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SynC · Editorial revision

Positive Displacement Pumps

Revision1
EditedOct 12, 2026
StatusCurrent
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Current revision. This is editorial revision 1, the current text of this standard. Read it on the standard's page.

SynC Standards Team — Specifier (Platform Standards) ✓ OfficialDiscloses employment SynC (SynC Platform Team)
Initial publication

1 Scope

1.1 Boundary of Work

NOTE This standard governs the positive displacement pump as a unit of supply: the pump end from its suction connection through its discharge connection, the drive train from the motor shaft to the pump shaft, the baseplate or support, the shaft seal, the relief device and the protective switches furnished with the pump, and the hopper and feed auger where the pump is fed dewatered solids. (1.1.1)
NOTE A positive displacement pump moves a fixed volume per revolution or per stroke and raises the pressure to whatever the discharge demands, so it needs three things a centrifugal pump does not: a relief path for a blocked discharge, protection against running without liquid, and a speed chosen for the abrasion the solids cause rather than for a point on a curve. Those three needs shape this standard. (1.1.2)
NOTE This standard is read with Common Work Results ProcessCommon Work Results for Process EquipmentResolves to the current adopted revision.sync/common-work-results-process, which carries the submittal procedures and the process equipment data sheet, the manufacturer qualification and unit responsibility, the site and service conditions, the equipment supports and anchorage basis, the vibration and airborne noise acceptance, the motor, drive, and control interface, guards, lubrication and first fills, the factory test and witnessing policy, the manufacturer's field services, startup, field performance and acceptance testing, training, delivery and storage, warranty, and spare parts and special tools for every item of process equipment; nothing there is restated here. (1.1.3)
NOTE Work outside this boundary is governed by the standards named below, and this standard defers to them rather than restating their requirements: (1.1.4)
  • The low-voltage motor, beyond the enclosure, service factor, duty, and inverter-duty features this standard states for it: Electric MotorsCommon Motor Requirements for Electrical EquipmentResolves to the current adopted revision.sync/electric-motors
  • The variable frequency drive, the starter, and the motor control center: Low Voltage Variable Frequency DrivesLow-Voltage Variable Frequency DrivesResolves to the current adopted revision.sync/low-voltage-variable-frequency-drives, Combination Motor StartersCombination and Manual Motor StartersResolves to the current adopted revision.sync/combination-motor-starters, and Motor Control CentersMotor Control CentersResolves to the current adopted revision.sync/motor-control-centers
  • Housekeeping pads, cast-in and post-installed anchors, non-shrink grout, and grouted base plates: Concrete PadsConcrete Equipment PadsResolves to the current adopted revision.sync/concrete-pads, Structural Steel Anchor BoltsAnchor Rods and Embedded SteelResolves to the current adopted revision.sync/structural-steel-anchor-bolts, Post Installed AnchorsPost-Installed Concrete and Masonry AnchorsResolves to the current adopted revision.sync/post-installed-anchors, Non Shrink GroutNon-Shrink GroutResolves to the current adopted revision.sync/non-shrink-grout, and Grouted Base PlatesGrouted Column Base Plates and Bearing PlatesResolves to the current adopted revision.sync/grouted-base-plates
  • Vibration isolators, inertia bases, flexible pipe connectors, and seismic restraint: Vibration Isolation And Seismic RestraintVibration Isolation and Seismic RestraintResolves to the current adopted revision.sync/vibration-isolation-and-seismic-restraint
  • Tagged pressure, level, temperature, and flow instruments, including the flow meter on a sludge line: Process InstrumentationProcess InstrumentationResolves to the current adopted revision.sync/process-instrumentation, Pressure InstrumentationPressure InstrumentationResolves to the current adopted revision.sync/pressure-instrumentation, and Flow MeasurementFlow MeasurementResolves to the current adopted revision.sync/flow-measurement
  • Control panels furnished with the pump or serving it, and the integration of the pump's points: Industrial Control PanelsIndustrial Control PanelsResolves to the current adopted revision.sync/industrial-control-panels and Control Systems IntegrationControl Systems Integration and TestingResolves to the current adopted revision.sync/control-systems-integration
  • The suction and discharge piping, its supports, and the flushing water piping to the connections this standard requires: Ductile Iron Process PipingDuctile Iron Process PipingResolves to the current adopted revision.sync/ductile-iron-process-piping, Steel And Stainless Process PipingSteel and Stainless Steel Process PipingResolves to the current adopted revision.sync/steel-and-stainless-process-piping, Plastic Process PipingPlastic Process PipingResolves to the current adopted revision.sync/plastic-process-piping, and Hangers And SupportsHangers and Supports for Mechanical Piping and EquipmentResolves to the current adopted revision.sync/hangers-and-supports
  • The check valve and the isolation valves on the discharge and suction: Process Check ValvesProcess Check ValvesResolves to the current adopted revision.sync/process-check-valves, Eccentric Plug ValvesEccentric Plug ValvesResolves to the current adopted revision.sync/eccentric-plug-valves, Knife Gate ValvesKnife Gate ValvesResolves to the current adopted revision.sync/knife-gate-valves, Resilient Seated Gate ValvesResilient-Seated Gate ValvesResolves to the current adopted revision.sync/resilient-seated-gate-valves, and Butterfly ValvesButterfly ValvesResolves to the current adopted revision.sync/butterfly-valves
  • The backflow preventer on a plant water flush or seal water connection: Backflow PreventionBackflow PreventionResolves to the current adopted revision.sync/backflow-prevention
  • The compressed air supply, filtration, and regulation serving an air-operated pump: Compressed Air SystemsCompressed Air SystemsResolves to the current adopted revision.sync/compressed-air-systems
  • The wet well, pit, gallery, and sump the pump sits in or draws from: Water Retaining Concrete StructuresWater-Retaining Concrete StructuresResolves to the current adopted revision.sync/water-retaining-concrete-structures
  • Field-applied finish coatings on the installed pump: High Performance CoatingsHigh-Performance CoatingsResolves to the current adopted revision.sync/high-performance-coatings
NOTE The process pump family is split four ways, and the other three members own what this one excludes: (1.1.5)
  • Horizontal end-suction, axially split-case double-suction, and self-priming centrifugal pumps for raw, settled, finished, service, seal, and plant water and for process transfer, including chemical process pumps: Horizontal Centrifugal Process PumpsHorizontal Centrifugal Process PumpsResolves to the current adopted revision.sync/horizontal-centrifugal-process-pumps
  • Line-shaft vertical turbine pumps in wet pits, cans, and wells, and submersible well pumps: Vertical Turbine PumpsVertical Turbine PumpsResolves to the current adopted revision.sync/vertical-turbine-pumps
  • Solids-handling wastewater pumps in every arrangement, submersible, dry-pit submersible, and self-priming, including chopper and screw-centrifugal pumps, for raw sewage, effluent, return and waste activated sludge, and plant drain: Submersible Solids Handling PumpsSubmersible Solids-Handling PumpsResolves to the current adopted revision.sync/submersible-solids-handling-pumps
NOTE Return activated sludge and dilute waste activated sludge are centrifugal duties at most plants and sit with the solids-handling standard; they enter this standard only where the process design selects a positive displacement pump for them, as it does for thickened waste activated sludge and for a plant that meters its wasting rate by pump speed. (1.1.6)
NOTE A positive displacement pump furnished as a component of a packaged system, such as the sludge feed pump of a dewatering package or the metering pump of a polymer feed skid, is governed by the standard for that system, and this standard applies to it only where the Contract Documents say so. Chemical metering pumps and their skids belong to a chemical feed systems standard not yet owned by a SynC standard, and the metering pumps of a building water treatment program stay with HVAC Water TreatmentHVAC Water TreatmentResolves to the current adopted revision.sync/hvac-water-treatment. (1.1.7)
NOTE A plant influent or sludge pump station built in a water-retaining structure with individually specified pumps is this family of standards; the factory-assembled site lift station with its own pumps, basin, valves, and panel is Packaged Pump StationsPackaged Pump and Lift StationsResolves to the current adopted revision.sync/packaged-pump-stations. (1.1.8)

1.2 Terms Used in This Standard

NOTE The following terms carry their Hydraulic Institute meanings throughout this standard: (1.2.1)
  • Rated capacity: the volume per unit time the pump delivers at the rated speed and the rated differential pressure, on the pumped fluid
  • Displacement: the theoretical volume per revolution or per stroke, before slip
  • Slip: the difference between displacement and delivered capacity, which rises with differential pressure and internal clearance and falls with viscosity
  • Volumetric efficiency: delivered capacity divided by displacement at the rated condition
  • Net positive inlet pressure available (NPIPA) and required (NPIPR): the rotary-pump terms of ANSI/HI 3.1-3.5 for the margin of inlet pressure above vapor pressure, with net positive suction head used in the same sense for reciprocating pumps under ANSI/HI 6.1-6.5
  • Acceleration head: the additional inlet pressure a reciprocating pump needs to accelerate the liquid column in the suction line on each stroke
  • Dry running: operation of the pump without liquid in the pumping elements, which destroys an elastomer stator or hose within minutes

2 Referenced Standards

2.1 Equipment, materials, and installation shall comply with the latest adopted edition of each of the following unless a specific edition is cited.
2.2 Where referenced standards conflict, the more stringent requirement shall govern unless the Engineer of Record directs otherwise in writing.
Standard Title
ANSI/HI 3.1-3.5 Rotary Pumps for Nomenclature, Definitions, Application, and Operation
ANSI/HI 3.6 Rotary Pump Tests
ANSI/HI 6.1-6.5 Reciprocating Power Pumps for Nomenclature, Definitions, Application, and Operation
ANSI/HI 6.6 Reciprocating Pump Tests
ANSI/HI 10.1-10.5 Air-Operated Pumps for Nomenclature, Definitions, Application, and Operation
ANSI/HI 10.6 Air-Operated Pump Tests
ANSI/HI 9.8 Rotodynamic Pumps for Pump Intake Design
ANSI/AGMA 6013 Standard for Industrial Enclosed Gear Drives
ANSI/ABMA 9 Load Ratings and Fatigue Life for Ball Bearings
ANSI/ABMA 11 Load Ratings and Fatigue Life for Roller Bearings
NEMA MG 1 Motors and Generators
NEMA 250 Enclosures for Electrical Equipment (1000 Volts Maximum)
NFPA 70 National Electrical Code (Articles 430 and 500 through 504)
NFPA 820 Standard for Fire Protection in Wastewater Treatment and Collection Facilities
ASME B16.1 Gray Iron Pipe Flanges and Flanged Fittings (Classes 25, 125, and 250)
ASME B16.5 Pipe Flanges and Flanged Fittings, NPS 1/2 Through NPS 24
ASME B16.42 Ductile Iron Pipe Flanges and Flanged Fittings (Classes 150 and 300)
ASME BPVC Section VIII, Division 1 Rules for Construction of Pressure Vessels
ASTM A48/A48M Gray Iron Castings
ASTM A536 Ductile Iron Castings
ASTM A743/A743M Castings, Iron-Chromium, Iron-Chromium-Nickel, Corrosion Resistant, for General Application
ASTM A276/A276M Stainless Steel Bars and Shapes
ASTM A564/A564M Hot-Rolled and Cold-Finished Age-Hardening Stainless Steel Bars and Shapes
ASTM B584 Copper Alloy Sand Castings for General Applications
ASTM D2000 Classification System for Rubber Products in Automotive Applications
ASTM D2240 Rubber Property, Durometer Hardness
SSPC-SP 6/NACE No. 3 Commercial Blast Cleaning
SSPC-SP 10/NACE No. 2 Near-White Metal Blast Cleaning
29 CFR 1910.219 Mechanical Power-Transmission Apparatus
GLUMRB Recommended Standards for Wastewater Facilities (Ten States Standards)
NOTE The Hydraulic Institute standards for rotary, reciprocating, and air-operated pumps are the product standards of this family; the rotodynamic standards for operating regions, NPSH margin, and vibration do not apply to a positive displacement pump, and this standard does not cite them. (2.3)

3 Submittals

3.1 Action Submittals

3.1.1 Submittals under this standard shall be made under the procedures of Common Work Results ProcessCommon Work Results for Process EquipmentResolves to the current adopted revision.sync/common-work-results-process, with the process equipment data sheet that standard requires completed for each pump.
3.1.2 The Contractor shall submit the following for review before any pump is released for fabrication:
  • Product data for each pump, identifying the pump type, model, size, number of stages or plungers, rotation, connection sizes and ratings, and shipping and operating weights
  • Certified performance curves for each pump plotted on water at the rated differential pressure and at the relief device set pressure, showing capacity, slip, and power against speed, with the manufacturer's correction for the viscosity and solids content of the pumped fluid stated
  • Selection report stating the rated capacity, the rated differential pressure, the selected speed as a percentage of the manufacturer's maximum continuous speed for the pumped fluid, the net positive inlet pressure required at that speed, and the brake horsepower at the relief device set pressure
  • Materials of construction for every wetted part, including the stator elastomer compound with its ASTM D2000 classification and durometer, the rotor base metal and surface treatment with plating thickness, the lobe, plunger, hose, or diaphragm material, and the seal faces and elastomers
  • Drive train data: gear reducer manufacturer, ratio, mechanical and thermal ratings, and service factor; coupling type and alignment tolerance; belt drive data; and motor data under Electric MotorsCommon Motor Requirements for Electrical EquipmentResolves to the current adopted revision.sync/electric-motors
  • Speed control data: the speed range, the turndown, and the constant-torque rating of the drive and motor across it
  • Relief device data: type, set pressure, capacity at set pressure, materials, and the return destination; rupture disc burst rating and holder data where furnished
  • Protective device data: the high-pressure switch or transmitter, the dry-run device, and the hose leak detector, with their setpoints and the wiring diagram of their interlocks
  • Shaft seal or packing data with the flush or lubrication arrangement, its flow rate, and its pressure
  • Baseplate drawing with the anchor bolt pattern, the grout dam and grout holes, and the operating and seismic loads
  • Suction and discharge piping arrangement review: the manufacturer's written confirmation of the arrangement shown on the drawings, including the net positive inlet pressure available, the pulsation provisions, and the relief return
  • Cake feed hopper drawings with the auger, bridge breaker, level sensing, and the pipeline pressure drop calculation where the pump is fed dewatered solids
  • Shop coating system data sheets
  • Listing of the motor and every electrical device for the hazardous location classification shown for the pump location
Action Submittals Requiredcheckbox
☑ Product data by pump
☑ Certified curves at rated and relief pressures with fluid correction
☑ Selection report with speed reserve and NPIP required
☑ Wetted materials with elastomer classification and plating thickness
☑ Drive train data
☑ Speed control and constant-torque data
☑ Relief device data
☑ Protective device data and interlock diagram
☑ Shaft seal or packing data with flush arrangement
☑ Baseplate drawing with loads
☑ Suction and discharge piping arrangement review
☐ Cake feed hopper drawings and pipeline calculation
☑ Shop coating system data
☐ Hazardous location listings
NOTE A positive displacement pump has no head-capacity curve; its curve is a family of capacity-against-speed lines, one per differential pressure, and the distance between the lines is the slip. The selection report matters because the speed the manufacturer chose decides how fast the stator, the lobes, or the hose wear, and the curve at the relief pressure is what sizes the motor. (3.1.3)

3.2 Closeout Submittals

3.2.1 In addition to the closeout submittals of Common Work Results ProcessCommon Work Results for Process EquipmentResolves to the current adopted revision.sync/common-work-results-process, the Contractor shall submit the following before the pumps are accepted:
  • Relief device record stating the set pressure as bench-tested at the factory and as verified in the field, and the burst rating of each rupture disc installed
  • Protective device setpoint record stating the high-pressure shutdown setpoint, the dry-run device setpoint or trip point, and the speed range as set in the drive
  • Factory performance test report for each pump tested, under the article on factory testing
  • Field performance test report recording the measured capacity, discharge pressure, speed, and motor current on the pumped fluid, plotted against the certified curve corrected for that fluid
  • Dimensional record of each stator bore and rotor, each set of lobes and wear plates, or each set of plungers and packing as shipped, for comparison at the first overhaul
Closeout Submittals Requiredcheckbox
☑ Relief device set pressure record
☑ Protective device setpoint record
☑ Factory performance test report
☑ Field performance test report on the pumped fluid
☐ As-shipped dimensional record of wear parts
NOTE Wear in a positive displacement pump shows up as a slow loss of capacity at the same speed rather than as a failure, and the operator who has the as-shipped dimensions and the startup capacity can tell a worn stator from a thickened sludge; the operator who has neither raises the speed until the pump fails. (3.2.2)

4 Quality Assurance

4.1 Manufacturer and Wear Parts

4.1.1 The stator, rotor, lobes, hose, plungers, and diaphragms shall be manufactured by the pump manufacturer, or manufactured to the pump manufacturer's design and warranted by the pump manufacturer as its own.
4.1.2 The reference installations the manufacturer identifies under Common Work Results ProcessCommon Work Results for Process EquipmentResolves to the current adopted revision.sync/common-work-results-process shall be of the pump type furnished, in sludge, scum, slurry, or solids service of a solids content comparable to the pumped fluid.
NOTE A manufacturer that sells a clean-liquid rotary pump into sludge service for the first time learns about abrasion on the Owner's stator, which is why the reference installations are required to be in a comparable service rather than merely of the same model. (4.1.3)

4.2 Drive Train Responsibility

4.2.1 The pump manufacturer shall select the gear reducer, the coupling or belt drive, and the motor for the pump, and shall mount and align the complete drive train on the common baseplate at the factory.
4.2.2 Where the variable frequency drive is furnished by another party under Common Work Results ProcessCommon Work Results for Process EquipmentResolves to the current adopted revision.sync/common-work-results-process, the pump manufacturer shall confirm in writing that the motor and the pump are rated for continuous operation across the speed range the drive will be set to.

4.3 Piping Arrangement Review

4.3.1 Before any pump is released for fabrication, the pump manufacturer shall review the suction and discharge piping arrangement shown on the process mechanical plans and sections and shall confirm in writing that the net positive inlet pressure available, the suction line size and length, the pulsation provisions, the relief return, and the flushing and cleanout connections are acceptable for the pump furnished.
4.3.2 Where the pump draws from a scum pit, a grit sump, or another open wet well, the manufacturer's review shall include the wet well geometry against ANSI/HI 9.8 for the submergence and the approach to the pump intake.
4.3.3 Where the pump is fed dewatered solids, the manufacturer's review shall include a pressure drop calculation for the cake pipeline at the rated capacity and the design solids content, and the calculation shall show the rated discharge pressure with the margin the manufacturer requires.
NOTE The review puts the party that knows the pump in front of the drawings while they can still change. A suction line that is one size too small, a relief valve that returns to the discharge side of the suction isolation valve, or a cake pipeline whose friction was estimated from water are the arrangement errors this review finds, and every one of them is a change order after the pump is set. (4.3.4)

5 Service Conditions

5.1 Pumped Fluid

5.1.1 The pumped fluid for each pump shall be as indicated in the datasheet, and every wetted part shall be selected for that fluid at its solids content, its temperature, and its abrasive and grease content.
Pumped Fluidselect
Primary sludge
Thickened waste activated sludge
Digested sludge
Scum and grease
Grit slurry
Dewatered cake
Water treatment residuals, alum or ferric sludge
Lime slurry
Septage or hauled waste
Polymer solution
Chemical sludge or process slurry
5.1.2 The design solids content of the pumped fluid shall be as indicated in the datasheet, expressed as percent total solids by weight.
Design Solids Contentrange
% total solids
0.51234568101215182025303540
Per drawings — the pump schedule and the process design criteria on the process mechanical drawings (deferred by default)
5.1.3 The pump and every wetted part shall be rated for continuous operation at the highest fluid temperature indicated in the datasheet.
Highest Continuous Fluid Temperaturerange
°F
326080100120140160180200212
Per drawings — the pump schedule on the process mechanical drawings (deferred by default)
NOTE Primary sludge carries grit, rags, and grease at low solids and is the service in which a pump sees the most abrasion per gallon; thickened waste activated sludge is a smooth, viscous fluid at four to eight percent solids that holds air and sheds water under shear; digested sludge is warm, gassy, and corrosive to iron at the vapor line; scum and grease float, congeal below roughly 90°F, and clog any passage that is not swept; grit slurry is water carrying sand, and it erodes a rotor or a lobe faster than any other service; dewatered cake at eighteen to thirty percent solids does not flow at all and has to be forced into the pump by an auger. Water treatment residuals are fine, non-abrasive, and thixotropic, lime slurry scales and settles wherever it stops, septage arrives at whatever solids the hauler brought, and polymer solution is viscous, shear-sensitive, and slippery. No single pump type suits all of these, which is why this field carries no default and the pump type field reads from it. (5.1.4)
NOTE Solids content is the one number that sets the viscosity, the abrasion, and the pressure drop of a sludge line together, and a pump bought for four percent sludge and fed eight percent after a thickener upgrade runs at twice the differential pressure and half the life. The schedule carries the design value because it belongs to the process design rather than to the pump. (5.1.5)

5.2 Suction Condition

5.2.1 The suction condition of each pump shall be as indicated in the datasheet.
Suction Conditionradio
○ Flooded suction from a tank, hopper, digester, or wet well above the pump
○ Suction lift from a pit, sump, or tank below the pump
○ Fed by a hopper and feed auger with dewatered solids
Per drawings — the process mechanical plans and sections (deferred by default)
5.2.2 Where the pump operates on a suction lift, the static suction lift from the lowest operating liquid level to the pump centerline shall be as indicated in the datasheet.
Static Suction Liftrange
ft
2468101215182025
Per drawings — the process mechanical sections and the pump schedule (deferred by default)
5.2.3 The net positive inlet pressure available and the suction lift capability of the pump shall be evaluated at the atmospheric pressure corresponding to AltitudeAltitudeParameterEach project supplies its own value.altitude.
NOTE A flooded suction is the condition nearly every sludge pump is designed for, because the sludge well or the digester sits above the pump room floor and the solids keep the pump primed. A lift is the condition of a scum pump pulling from a pit and of a portable pump, and it is where a positive displacement pump earns its keep, since a rotary or reciprocating pump pulls a vacuum that a centrifugal pump cannot; the lift it can sustain falls with the vapor pressure of warm sludge, with the gas the sludge holds, and with every foot of site elevation. A cake hopper is neither: the solids have no head and are pushed into the pump by the auger, and the pump's inlet condition is the auger's feed pressure. (5.2.4)

5.3 Installation Environment

5.3.1 Where the pump is installed outdoors or in an unheated space, the stator, hose, lobe, and diaphragm elastomers, the gear oil, and the hose lubricant shall be rated by their manufacturers for Site Ambient Temperature MinimumSite Ambient Temperature MinimumParameterEach project supplies its own value.site-ambient-temperature-minimum, and the gear reducer thermal rating shall be confirmed at Site Ambient Temperature MaximumSite Ambient Temperature MaximumParameterEach project supplies its own value.site-ambient-temperature-maximum.
5.3.2 The hazardous location classification of the pump location, the enclosure type of the equipment-mounted electrical devices, and the washdown and corrosive-atmosphere provisions shall be as required under Common Work Results ProcessCommon Work Results for Process EquipmentResolves to the current adopted revision.sync/common-work-results-process for the space shown on the hazardous area classification drawings and the process mechanical plans.

6 Capacity and Speed

6.1 Rated Duty

6.1.1 The number of pumps serving each service shall be as indicated in the datasheet.
Pumps per Servicerange
pumps
123456
Per drawings — the pump schedule on the process mechanical drawings (deferred by default)
6.1.2 Each pump shall deliver the rated capacity indicated in the datasheet on the pumped fluid at the rated differential pressure.
Rated Capacityrange
gpm
12510152030405075100150200250300400500600750100015002000
Per drawings — the pump schedule on the process mechanical drawings (deferred by default)
6.1.3 The rated discharge pressure of each pump shall be as indicated in the datasheet.
Rated Discharge Pressurerange
psig
1015202530405060759010012515017520025030040050060075010001500
Per drawings — the pump schedule on the process mechanical drawings (deferred by default)
6.1.4 The rated capacity shall be delivered with the slip at the rated differential pressure deducted, on the pumped fluid at its design solids content, and not on water.
6.1.5 Where a service is served by more than one pump, the standby arrangement and the pumps that run together shall be as indicated on the pump schedule and the process and instrumentation diagrams.

6.2 Speed and Speed Reserve

6.2.1 A rotary pump shall deliver the rated capacity at a speed not exceeding the value indicated in the datasheet.
Rotary Pump Speed at Rated Capacityrange
RPM
25507510015020025030035040045050060075090012001800
Per drawings — the pump schedule on the process mechanical drawings (deferred by default)
6.2.2 A reciprocating pump shall deliver the rated capacity at a stroke rate not exceeding the value indicated in the datasheet.
Reciprocating Pump Stroke Rate at Rated Capacityrange
strokes per minute
10203040506080100120150200300
Per drawings — the pump schedule on the process mechanical drawings (deferred by default)
6.2.3 The speed at which the pump delivers the rated capacity shall not exceed the percentage of the manufacturer's published maximum continuous speed for the pumped fluid indicated in the datasheet.
Speed at Rated Capacity, Percent of Maximum Continuous Speed for the Fluidrange
%
4050607075808590100
6.2.4 The manufacturer's published maximum continuous speed for the pumped fluid, the basis on which it was published, and the speed reserve remaining above the rated speed shall be stated in the selection report.
NOTE Speed is the wear rate in a positive displacement pump. The stator of a progressive cavity pump, the rubber of a lobe, and the wall of a hose each wear in proportion to the rubbing distance per gallon, so halving the speed and doubling the pump size roughly doubles the life of the wear parts for the same capacity; the cost is a larger pump, a larger reducer, and more floor. Manufacturers publish a maximum continuous speed for each fluid class, lowest for grit slurry and highest for clean viscous liquids, and the speed reserve field holds the selected speed below that limit so the operator can raise the speed to recover capacity as the pump wears rather than replacing the stator at the first loss of flow. (6.2.5)
NOTE Rotary lobe pumps and progressive cavity pumps in grit-bearing primary sludge are commonly held between 100 and 300 RPM, hose pumps lower still because the hose flexes once per shoe pass, and plunger pumps between 30 and 60 strokes per minute, where the ball checks have time to seat; a polymer solution or a non-abrasive residual tolerates speeds several times higher. A project writes the absolute cap where it has a wear history on the service, and the percentage reserve where it does not. (6.2.6)

6.3 Inlet Pressure

6.3.1 The Engineer of Record shall calculate the net positive inlet pressure available at the pump suction at the rated capacity, accounting for atmospheric pressure at the site, static head or lift, suction line friction on the pumped fluid at its design solids content and viscosity, the vapor pressure at the highest fluid temperature, and, for a reciprocating pump, the acceleration head per ANSI/HI 6.1-6.5.
6.3.2 The net positive inlet pressure available at the rated capacity shall be as indicated in the datasheet.
Net Positive Inlet Pressure Available at Rated Capacityrange
psi
12345681012152025304050
Per drawings — the pump schedule on the process mechanical drawings (deferred by default)
6.3.3 The net positive inlet pressure required by the pump at the rated speed on the pumped fluid shall be less than the net positive inlet pressure available by not less than the margin indicated in the datasheet.
Net Positive Inlet Pressure Marginrange
psi
12345710
6.3.4 Where the pumped fluid is thickened sludge, dewatered cake, or another fluid whose viscosity depends on shear rate, the net positive inlet pressure required shall be stated by the manufacturer for that fluid at the design solids content, not for water.
NOTE A positive displacement pump that is starved at the inlet does not cavitate the way a centrifugal pump does; the cavity simply does not fill, the capacity falls, and the pump runs on in a condition that reads like wear. Thickened sludge is the fluid that starves a pump most often, because its apparent viscosity rises steeply with solids content and the suction line friction with it, and a reciprocating pump adds the acceleration head of starting and stopping the whole suction column on every stroke. The margin field is small in absolute terms because the inlet pressure available on a flooded sludge well is itself only a few psi. (6.3.5)

6.4 Viscosity and Solids Correction

6.4.1 The pump selection, the drive power, and the net positive inlet pressure required shall be corrected by the manufacturer for the viscosity of the pumped fluid at the design solids content and the lowest fluid temperature, and the correction basis shall be stated in the selection report.
6.4.2 The brake horsepower used to size the motor and the reducer shall be the power at the relief device set pressure on the pumped fluid at its highest viscosity.
NOTE Municipal sludge above roughly three percent solids is not a Newtonian fluid: its apparent viscosity falls as shear rises, so it flows more easily at high velocity than at low, and the viscosity a manufacturer measured in a cup bears little relation to the viscosity in a moving pipeline. The correction the manufacturer applies is drawn from its own test data on sludge at the stated solids content, which is why the report has to say what the correction was based on. (6.4.3)

7 Pump Type

7.1 Type Selection

7.1.1 The pump type for each service shall be as indicated in the datasheet.
Pump Typeselect
Progressive cavity
Rotary lobe
Plunger, reciprocating
Piston, reciprocating
Peristaltic hose
Air-operated double-diaphragm
7.1.2 The pump orientation shall be as indicated in the datasheet.
Pump Orientationradio
○ Horizontal
○ Vertical, drive above the pump
Per drawings — the process mechanical plans and sections (deferred by default)
NOTE A progressive cavity pump delivers a smooth, nearly pulse-free flow across a wide pressure range, meters by speed, tolerates grit at low speed, and passes fibrous solids poorly; its stator is the wear part, it is long, and it is destroyed in minutes by dry running. A rotary lobe pump is short, is opened from the front for service in place, passes rags and larger solids, runs in either direction, and slips more at pressure than a progressive cavity pump, so it is less a metering pump and more a transfer pump; its lobes and wear plates are the wear parts. A plunger pump reaches the highest pressures of the family and keeps delivering on grit, rags, and gas-bound sludge that would stop the others, which is why it has pumped primary sludge for a century; it pulses, it is heavy, its ball checks pass what they can lift, and its capacity turndown comes from stroke or speed. A piston pump, double-acting, delivers more evenly than a plunger pump at the same stroke rate and is the design of hydraulically driven cake pumps for long cake pipelines at pressures in the hundreds of psi. (7.1.3)
NOTE A peristaltic hose pump has no seal, no valve, and nothing wetted but the hose, so it is indifferent to grit, lime, and polymer and it reverses and self-primes; it pulses, its hose is a consumable with a life measured in hundreds of hours at high pressure, and it is limited to the lower pressures and capacities of the family. An air-operated double-diaphragm pump needs no motor, runs dry and deadheads without harm, and is the pump of a scum pit, a sump, and a portable or hazardous-location duty; it consumes compressed air inefficiently, pulses, and its capacity falls as the discharge pressure rises toward the air pressure. The fluid field above decides most of this choice, and the number of candidates for a given fluid is usually two. (7.1.4)

8 Progressive Cavity Pump Construction

8.1 Rotor and Stator

8.1.1 Requirements in this article apply where a progressive cavity pump is selected in the datasheet.
8.1.2 The number of stages shall be as indicated in the datasheet.
Number of Stagesrange
stages
123468
Derived — the rated differential pressure and the differential pressure per stage indicated in this datasheet (by default)
8.1.3 The differential pressure carried by each stage at the rated discharge pressure shall not exceed the value indicated in the datasheet.
Differential Pressure per Stagerange
psi
3045607590
8.1.4 The rotor shall be of the base material indicated in the datasheet.
Rotor Base Materialselect
Alloy steel
Tool steel
Type 420 stainless steel
Type 316 stainless steel
Type 17-4 PH stainless steel
Duplex stainless steel
8.1.5 The rotor surface shall be as indicated in the datasheet.
Rotor Surface Treatmentselect
Hard chrome plating
Tungsten carbide thermal spray coating
Chromium oxide ceramic coating
Uncoated, polished base metal
8.1.6 Where the rotor is hard chrome plated, the plating thickness shall be not less than the value indicated in the datasheet, measured on the rotor surface after finishing.
Rotor Chrome Plating Thicknessrange
in.
0.0040.0060.0080.010.0120.0160.02
Default: Not less than 0.01 in.
8.1.7 The stator elastomer shall be of the compound indicated in the datasheet, classified under ASTM D2000, with the durometer hardness per ASTM D2240 stated in the submittal.
Stator Elastomerselect
Nitrile, NBR
Hydrogenated nitrile, HNBR
EPDM
Fluoroelastomer, FKM
Natural rubber
Polyurethane
8.1.8 The stator construction shall be as indicated in the datasheet.
Stator Constructionradio
● Elastomer bonded in a steel tube
○ Replaceable elastomer insert in a reusable tube
○ Adjustable stator with external compression adjustment
○ Uniform-wall elastomer in a profiled tube
8.1.9 The stator tube shall be furnished with the lifting and handling provisions the stator's weight requires, and the stator shall be removable from the pump without removing the suction housing from the piping.
NOTE The number of stages is arithmetic once the pressure per stage is chosen: a 150 psi duty at 75 psi per stage is a two-stage pump, and at 45 psi per stage a four-stage pump. The pressure per stage is the real decision. Seventy-five psi is the rating the stator geometry carries on clean viscous liquids, and the one most manufacturers publish; at that loading on grit-bearing sludge the slip rises quickly as the stator wears, so sludge pumps are commonly derated to 45 or 60 psi per stage, which lengthens the pump and extends the interval between stator changes. Ninety psi per stage is a rating some manufacturers publish for particular geometries and is a position for a clean, non-abrasive fluid where length is the constraint. (8.1.10)
NOTE Hard chrome over alloy or tool steel is the rotor nearly every sludge pump is shipped with; the chrome resists the grit and the steel is inexpensive to remachine, and once the chrome is through, the rotor is replaced or replated. A stainless base metal is chosen where the fluid attacks steel exposed at a chrome pinhole, as digested sludge and some chemical sludges do, and Type 316 or duplex under chrome is the rotor of a corrosive service; Type 420 and 17-4 PH harden and are chosen where the rotor runs uncoated. A tungsten carbide spray outlasts chrome several times over on grit slurry and costs several times as much, and a chromium oxide ceramic resists chemical attack that would lift chrome; an uncoated stainless rotor is a position for polymer, residuals, and other non-abrasive fluids. (8.1.11)
NOTE Nitrile is the stator of municipal sludge: it resists the grease and the hydrocarbons sludge carries, it is abrasion resistant, and it is the compound every manufacturer stocks, which is why it is the default. Hydrogenated nitrile keeps the same chemistry to a higher temperature and is bought for digested sludge heated above the limit of nitrile. EPDM resists hot water, polymer, and most inorganic chemicals and swells in grease, so it is the stator of a polymer or chemical duty and not of a sludge duty. Fluoroelastomer serves the chemical sludges and hot fluids that attack the others, at a price and with lower abrasion resistance. Natural rubber has the highest abrasion resistance of the family and the lowest tolerance for oils and heat, and it is the stator of a grit slurry or a lime slurry. Polyurethane resists abrasion and tearing and swells in hot water, and it is a position for a cold abrasive slurry. (8.1.12)
NOTE A bonded stator is the conventional construction: the elastomer is molded to the tube and the whole tube is the replacement part. A replaceable insert keeps the tube and replaces only the elastomer, which cuts the part cost and requires the insert to be seated correctly in the field. An adjustable stator lets the operator take up wear by compressing the elastomer from outside, which recovers slip without a stator change until the elastomer is spent, at the cost of a stator that someone has to adjust. A uniform-wall stator puts the same elastomer thickness around the whole cavity, which runs cooler, holds pressure at a lower stage count, and swells less in a hot fluid, and it is the construction of the higher-pressure and higher-temperature duties. (8.1.13)

8.2 Drive Shaft and Joints

8.2.1 The joints connecting the rotor to the drive shaft shall be of the type indicated in the datasheet.
Rotor Drive Joint Typeradio
○ Sealed pin joint
○ Sealed crowned-gear joint
○ Flexible shaft without joints
8.2.2 Each pin or gear joint shall be sealed from the pumped fluid by an elastomer sleeve retained by stainless steel bands, and the joint cavity shall be filled with the manufacturer's joint lubricant at the factory.
8.2.3 The connecting rod and the drive shaft shall be of the material indicated in the datasheet.
Connecting Rod and Drive Shaft Materialselect
Type 316 stainless steel
Type 17-4 PH stainless steel
Type 420 stainless steel
Alloy steel, hard chrome plated
8.2.4 The drive shaft shall carry a renewable sleeve or a hardened and polished surface through the seal, and the shaft shall be supported by bearings in the bearing housing rather than by the reducer output bearings unless the pump is furnished as an integral gearmotor unit the manufacturer rates for that load.
NOTE A pin joint is the simplest and least expensive joint, carries the torque on a single pin and bushing, and is the joint of small and medium sludge pumps; its pin and bushings wear and are inspected through the suction housing port. A crowned-gear joint carries the torque on a full set of teeth, runs at a lower contact stress, and is the joint of large pumps and of the high-torque cake pumps, at a higher price; both depend on the sleeve to keep sludge out of the lubricant. A flexible shaft has no joints to seal or wear and no lubricant to lose, and it is limited to the small pumps whose torque and rotor eccentricity a flexing rod can carry. (8.2.5)
NOTE Type 316 is the rod and shaft of most sludge pumps, immune to the fluid and strong enough for the torque; 17-4 PH is bought where the torque of a large or high-pressure pump exceeds what Type 316 carries at the rod diameter available; Type 420 hardens for a shaft that runs a seal directly on its surface; chrome-plated alloy steel is the lowest first cost and corrodes at the first break in the plating. (8.2.6)

8.3 Suction Housing and Access

8.3.1 The suction housing shall be furnished with the features indicated in the datasheet.
Progressive Cavity Pump Housing Featurescheckbox
☑ Cleanout port on the suction housing with a gasketed, bolted cover
☐ Inspection port large enough to inspect and change the drive joint through the housing
☐ Maintain-in-place construction with the stator and rotor removable without disturbing the suction or discharge piping
☑ Drain connection at the low point of the suction housing
☐ Bearing housing drain to carry seal leakage clear of the bearings
8.3.2 The suction housing shall be of the casing material selected under the article on connections and casing material, and the discharge flange and stator tube shall be rated for the relief device set pressure.
NOTE The cleanout port is the operator's only way to reach a rag wrapped on the joint or a stone wedged at the stator entry without pulling the stator, and a pump without one is a pump that is dismantled for every blockage. Maintain-in-place construction, in which the stator slides off and the rotor withdraws through a gap in the discharge piping, turns a stator change from a two-day job with a pipe fitter into a half-day job for the pump mechanic; it costs a longer footprint and a spool in the discharge. (8.3.3)

8.4 Dry-Run Protection

8.4.1 Each progressive cavity pump shall be furnished with the dry-run protection indicated in the datasheet, and the dry-run device shall stop the pump through a hardwired interlock in the starter or drive and shall alarm to the plant control system under Control Systems IntegrationControl Systems Integration and TestingResolves to the current adopted revision.sync/control-systems-integration.
Dry-Run Protectioncheckbox
☑ Temperature sensor embedded in the stator elastomer
☐ Motor power monitor relay with an underload trip
☐ Suction pressure or vacuum switch
☐ Flow switch on the discharge
☐ Low level interlock from the feed tank or wet well
8.4.2 The dry-run trip shall lock out the pump until it is reset locally, and the pump shall not restart automatically after a dry-run trip.
NOTE A stator run dry heats at the rotor contact line to the point of charring in a minute or two, and the damage is complete before an operator notices. A sensor embedded in the elastomer reads that temperature rise directly and is the protection nearly every manufacturer builds in and nearly every specification requires, which is why it is the default. A power monitor reads the drop in motor load when the pump empties and also catches a broken joint; it does not see a stator running warm on a half-full suction. A suction switch and a flow switch each watch a symptom one step removed, and a level interlock on the feed tank prevents the condition rather than detecting it. Projects commonly select the stator sensor with one of the others. (8.4.3)

9 Rotary Lobe Pump Construction

9.1 Lobes

9.1.1 Requirements in this article apply where a rotary lobe pump is selected in the datasheet.
9.1.2 The lobe profile shall be as indicated in the datasheet.
Lobe Profileradio
○ Two-lobe, bi-wing
○ Three-lobe
○ Multi-lobe, four or more lobes
○ Helical lobe
9.1.3 The lobes shall be of the material indicated in the datasheet.
Lobe Materialselect
Nitrile-covered steel core
Hydrogenated nitrile-covered steel core
EPDM-covered steel core
Fluoroelastomer-covered steel core
Polyurethane-covered steel core
Type 316 stainless steel, uncovered
Hardened alloy steel, uncovered
9.1.4 The lobes shall be secured to their shafts so that they can be removed and replaced through the front cover without disturbing the timing gears or the shaft seals.
NOTE Fewer lobes means a larger pocket per revolution: a two-lobe rotor passes the largest solid and pulses the most, a three-lobe rotor is the general-purpose profile of sludge service, and a multi-lobe rotor delivers the smoothest flow with the smallest passage. A helical lobe twists the pocket along the shaft so that the flow is nearly pulse-free and the lobes mesh gradually, which lowers noise and pulsation on long discharge lines at a higher rotor cost. (9.1.5)
NOTE An elastomer-covered lobe seals against the housing with a slight interference, so the pump holds its capacity against pressure and the rubber takes the grit; the cover is renewed by replacing the lobe. Nitrile is the cover of municipal sludge for the reasons it is the stator of a progressive cavity pump, hydrogenated nitrile extends it to hot digested sludge, EPDM serves polymer and inorganic chemistry, fluoroelastomer serves hot and aggressive fluids, and polyurethane resists abrasion in a cold slurry. A metal lobe runs with a clearance rather than an interference, slips more, and tolerates temperatures and chemicals no elastomer does; hardened steel is chosen for grit at low pressure and stainless for a corrosive clean fluid. (9.1.6)

9.2 Wear Plates and Housing Access

9.2.1 The pump chamber shall be lined with replaceable wear plates on the front cover and the rear wall, and with a replaceable radial liner where the manufacturer's design provides one, each of the material indicated in the datasheet.
Wear Plate Materialselect
Hardened alloy steel
Type 316 stainless steel
Duplex stainless steel
Tungsten carbide hard-faced steel
9.2.2 The front cover shall be removable with hand tools, without disconnecting the suction or discharge piping, to expose the lobes, the wear plates, and the shaft seals for inspection and replacement in place.
9.2.3 The timing gears and bearings shall be housed in an oil-filled gear case separated from the pump chamber by the shaft seals and by an intermediate chamber that drains to the exterior, so that seal leakage is visible at the drain and cannot reach the gear oil.
9.2.4 Both shafts shall be supported on bearings in the gear case, and the lobes shall be overhung from those bearings with no bearing or bushing in the pumped fluid.

10 Plunger and Piston Pump Construction

10.1 Plungers and Power End

10.1.1 Requirements in this article apply where a plunger or piston pump is selected in the datasheet.
10.1.2 The number of plungers or pistons per pump shall be as indicated in the datasheet.
Plungers per Pumprange
plungers
1234
10.1.3 Capacity adjustment shall be provided as indicated in the datasheet.
Capacity Adjustmentradio
○ Variable speed with a fixed stroke
○ Manually adjustable stroke length at constant speed
○ Variable speed and manually adjustable stroke length
10.1.4 The plungers shall be of the material indicated in the datasheet.
Plunger Materialselect
Alloy steel, hard chrome plated
Type 17-4 PH stainless steel, hard chrome plated
Type 316 stainless steel, hard chrome plated
Solid ceramic
Ceramic-coated steel
Tungsten carbide coated steel
10.1.5 The power end shall be lubricated as indicated in the datasheet, with the crankshaft and connecting rods running in an enclosed crankcase and the crosshead guided so that no side load reaches the plunger.
Power End Lubricationradio
● Splash lubrication from an oil bath in the crankcase
○ Forced lubrication with a pump-driven oil pump
○ Grease-lubricated bearings
10.1.6 The crankcase shall be furnished with an oil level sight gauge, a fill connection, a vented breather, and a drain piped to a point where it can be reached with the pump installed.
NOTE A simplex pump delivers one pulse per revolution and is the smallest and least expensive; a duplex pump halves the pulsation, and a triplex pump, with its three plungers on cranks 120 degrees apart, delivers the flow evenly enough that the discharge piping sees only a few percent of variation, which is why triplex is the arrangement of larger sludge and cake duties and of any long discharge line. Quadruplex pumps appear at the largest capacities. Capacity adjustment by speed keeps the stroke, and therefore the ball lift, the same at every rate and suits a drive-fed pump; an adjustable stroke changes capacity with the pump running at constant speed and is the adjustment of a pump on an across-the-line starter, at the cost of a short stroke that lifts the balls less. (10.1.7)
NOTE Chrome-plated steel is the plunger of general sludge service and the least expensive to renew; a plated stainless core is chosen where digested or chemical sludge corrodes the steel at a plating defect; a solid ceramic plunger is immune to the fluid and outlasts chrome on grit several times over, and it shatters if struck, so it is handled and packed with care; ceramic and carbide coatings put a hard surface on a steel core at a cost between the two. Splash lubrication is the standard power end of a crank-driven sludge pump and needs only an oil level; forced lubrication is the power end of a large, continuously running pump whose bearings a splash will not reach, and grease serves the smallest pumps. (10.1.8)

10.2 Check Valves

10.2.1 Each pumping chamber shall be fitted with a suction check valve and a discharge check valve of the type indicated in the datasheet, each removable for inspection through its own cover without disturbing the piping or the plunger.
Plunger Pump Check Valve Typeradio
○ Free ball check valve
○ Guided ball check valve
○ Spring-loaded ball check valve
○ Disc or poppet check valve
10.2.2 The check valve balls shall be of the material indicated in the datasheet.
Check Valve Ball Materialselect
Hardened alloy steel
Type 440C stainless steel
Type 316 stainless steel
Nitrile-covered steel core
Polyurethane-covered steel core
Ceramic
10.2.3 The check valve seats shall be of the material indicated in the datasheet.
Check Valve Seat Materialselect
Hardened alloy steel
Type 316 stainless steel
Type 440C stainless steel
Cobalt-chromium hard-faced steel
Nitrile-lined steel
NOTE A free ball sits on its seat under its own weight and lifts with the flow, so it passes any solid it can lift over and seats on grit by rolling to a fresh surface each stroke; it is the valve that made the plunger pump the primary sludge pump, and it is the slowest to seat. A guided ball travels in a cage that limits its lift and returns it squarely, which allows a higher stroke rate at the cost of a cage that rags can foul. A spring-loaded ball seats before reverse flow begins, which is what a high-pressure cake pump needs and what a grit slurry wears out. A disc or poppet valve seats on a flat face, seals best on a clean fluid, and holds a solid open. (10.2.4)
NOTE Hard steel balls and seats are the pair of general sludge service and are renewed as a set; a stainless pair is chosen where the sludge corrodes steel; a rubber-covered ball on a metal seat seals on grit and rags that hold a hard ball off its seat, and the cover wears; a ceramic ball on a hard-faced seat is bought for grit slurry and lime, where it outlasts steel many times over. The seat is normally the harder of the pair, so that the ball, which is the cheaper part to replace, takes the wear. (10.2.5)

10.3 Packing and Pulsation Control

10.3.1 Each plunger shall run through an adjustable stuffing box with a lantern ring and a connection for the lubrication or flush indicated in the datasheet.
Plunger Packing Lubricationradio
○ Manual grease cups at each stuffing box
○ Automatic grease lubricator driven from the pump
○ Plant water flush through the lantern ring
10.3.2 Pulsation control shall be provided as indicated in the datasheet, with each dampener sized by the pump manufacturer for the stroke volume, the stroke rate, and the piping arrangement, and charged to the pressure the manufacturer states.
Pulsation Controlcheckbox
☐ Bladder-type pulsation dampener on the discharge
☐ Suction stabilizer on the suction
10.3.3 A pulsation dampener whose shell falls within the scope of ASME BPVC Section VIII, Division 1 shall be built and stamped under it, with a bladder of an elastomer compatible with the pumped fluid and a charging valve and gauge.
NOTE Grease cups are the lubrication of most plunger sludge pumps and depend on an operator who turns them; an automatic lubricator driven from the crankshaft delivers a measured shot on every stroke and removes that dependence for the price of a lubricator and its reservoir; a water flush keeps grease out of the sludge, which a dewatering process downstream can care about, and needs a plant water connection with a backflow preventer. A discharge dampener absorbs the pulse of each stroke so that the piping, the flow meter, and the check valves downstream see a steady flow, and a suction stabilizer does the same job on the inlet side, where the acceleration head is otherwise subtracted from the inlet pressure available; neither is defaulted because a short, stiff discharge from a triplex pump often needs neither and a long line from a simplex pump needs both. (10.3.4)

11 Peristaltic Hose Pump Construction

11.1 Hose and Compression

11.1.1 Requirements in this article apply where a peristaltic hose pump is selected in the datasheet.
11.1.2 The hose shall be of the material indicated in the datasheet, reinforced with textile plies, and rated by the manufacturer for the rated discharge pressure on the pumped fluid.
Hose Materialselect
Natural rubber
Nitrile, NBR
EPDM
Chlorosulfonated polyethylene, CSM
Fluoroelastomer-lined, FKM
11.1.3 The hose shall be compressed by the mechanism indicated in the datasheet.
Hose Compression Mechanismradio
○ Rotating shoes
○ Rollers
11.1.4 The pump casing shall be filled with the hose lubricant indicated in the datasheet, and the lubricant type and quantity shall be stated on the pump nameplate and in the operation and maintenance manual.
Hose Lubricantradio
○ Glycerin-based lubricant
○ Silicone-based lubricant
○ NSF H1 food-grade lubricant
Manufacturer's standard (by default)
NOTE Natural rubber is the hose of abrasive service, with the highest resilience and abrasion resistance of the family and the lowest tolerance for oils, grease, and heat, which makes it the hose of a lime slurry, a grit slurry, and a residuals duty and a poor hose for scum. Nitrile resists the oils and grease of sludge and scum at a somewhat shorter flex life. EPDM resists polymer, hot water, and oxidizing chemicals and swells in grease. Chlorosulfonated polyethylene resists strong oxidizers and ozone. A fluoroelastomer-lined hose carries the chemical resistance of the lining on a flexible carcass for the fluids that attack everything else, at the highest price. A shoe compresses the hose along a surface and runs in a lubricant bath, which is the construction of the higher-pressure pumps; rollers compress along a line, generate less heat and need less drive power, and are the construction of the lower-pressure pumps. (11.1.5)

11.2 Hose Failure Detection and Connections

11.2.1 Each hose pump shall be furnished with the hose failure detection indicated in the datasheet, wired to stop the pump and to alarm to the plant control system under Control Systems IntegrationControl Systems Integration and TestingResolves to the current adopted revision.sync/control-systems-integration.
Hose Failure Detectionradio
● Leak detector in the pump casing, wired to stop the pump
○ Casing sight glass with visual inspection only
11.2.2 The hose shall terminate in flanged inserts of a material compatible with the pumped fluid, clamped so that the hose can be replaced through the casing cover without disconnecting the piping.
11.2.3 The casing shall be furnished with a drain at its low point and a fill port for the lubricant, and the lubricant shall be contained so that a hose failure cannot discharge lubricant into the piping.
NOTE A hose fails by rupture at the end of its flex life, and when it does the pumped fluid enters the lubricant bath and, if the pump keeps running, is pumped out through the casing drain or the breather onto the floor. A leak detector reads the fluid in the casing and stops the pump within a revolution; a sight glass tells the next operator who walks past. (11.2.4)

12 Air-Operated Double-Diaphragm Pump Construction

12.1 Wetted Parts

12.1.1 Requirements in this article apply where an air-operated double-diaphragm pump is selected in the datasheet.
12.1.2 The wetted body shall be of the material indicated in the datasheet.
Diaphragm Pump Body Materialselect
Aluminum
Cast iron
Type 316 stainless steel
Polypropylene
Polyvinylidene fluoride, PVDF
12.1.3 The diaphragms shall be of the material indicated in the datasheet.
Diaphragm Materialselect
Nitrile, NBR
Thermoplastic elastomer, TPE
EPDM
Fluoroelastomer, FKM
Polyurethane
PTFE with an elastomer backup diaphragm
12.1.4 The check valves shall be of the type indicated in the datasheet, of a material matched to the diaphragm material or of stainless steel.
Diaphragm Pump Check Valve Typeradio
○ Ball check valves
○ Flap check valves
NOTE Aluminum is the body of a general-purpose portable pump, light and inexpensive, and it corrodes in digested sludge and in any chemical fluid; cast iron is the body of a fixed sludge and scum duty; stainless steel serves a corrosive fluid and a washdown area; polypropylene and PVDF are the bodies of chemical and polymer service and are limited in temperature and in the pressure the plastic carries. Nitrile diaphragms serve sludge and scum, a thermoplastic elastomer flexes longer in abrasive service, EPDM serves polymer and inorganic chemicals, fluoroelastomer serves hot and aggressive fluids, polyurethane resists abrasion, and a PTFE-faced diaphragm with an elastomer backup carries chemical resistance the others lack at a shorter flex life. Ball checks seal best and pass solids up to roughly a quarter of the port; flap checks pass a solid nearly the size of the port and seal less well, and they are the valve of a scum and rag duty. (12.1.5)

12.2 Air Supply and Accessories

12.2.1 The pump shall be rated to deliver the rated capacity at the rated discharge pressure with the air supply pressure indicated in the datasheet at the pump inlet, and the air consumption at that condition shall be stated in the submittal.
Air Supply Pressure at the Pumprange
psig
40608090100110125
Per drawings — the compressed air schedule and the pump schedule (deferred by default)
12.2.2 The air valve shall be of a non-stalling, lubrication-free design that restarts from any position after a stop, and the air exhaust shall be muffled.
12.2.3 The pump shall be furnished with the accessories indicated in the datasheet.
Diaphragm Pump Accessoriescheckbox
☑ Air filter and pressure regulator with gauge at the pump
☐ Solenoid air valve for remote start and stop
☐ Stroke counter or cycle sensor
☐ Discharge pulsation dampener
☐ Exhaust muffler piped to a point outside the pump enclosure or pit
☐ Portable cart with suction and discharge hoses and a lifting bail
12.2.4 A pump installed in a location classified under NFPA 820 shall be bonded to the grounding system through a grounding lug on the pump body, and its diaphragms and body shall be of a conductive construction the manufacturer rates for that location.
NOTE A diaphragm pump is driven by the air pressure difference across the diaphragm, so the discharge pressure it can reach is the air pressure less the losses in the air valve, and a 60 psig plant air system cannot drive 50 psig of sludge head; the air schedule carries the supply pressure because the air system, not the pump, decides it. The regulator is defaulted because an unregulated pump runs at whatever the header supplies and consumes air in proportion; the solenoid valve is what lets a level controller start and stop the pump, and the stroke counter is what lets it be totalized. (12.2.5)

13 Shaft Sealing

13.1 Seal Type

13.1.1 The shaft seal of each progressive cavity, rotary lobe, plunger, and piston pump shall be of the type indicated in the datasheet, rated for the seal chamber pressure at the relief device set pressure and for the pumped fluid at its highest temperature.
Shaft Seal Typeradio
○ Compression packing with a lantern ring
○ Single mechanical seal, component
○ Single cartridge mechanical seal
○ Dual mechanical seal with a barrier or buffer fluid
○ Lip seals
13.1.2 The seal faces of a mechanical seal shall be of the combination indicated in the datasheet.
Mechanical Seal Face Combinationselect
Silicon carbide against silicon carbide
Tungsten carbide against tungsten carbide
Silicon carbide against tungsten carbide
Carbon against silicon carbide
13.1.3 Where the pumped fluid carries grit or fibrous solids, the seal faces shall be a hard face against a hard face.
13.1.4 Seal elastomers shall be of the same compound family as the stator, lobe, or hose elastomer selected for the pump, unless the seal manufacturer rates a different compound for the fluid.
NOTE Compression packing tolerates grit, is adjusted and repacked by a mechanic with no special tools, and leaks by design; it is still the seal of most plunger pumps and of many progressive cavity pumps in primary sludge, where a mechanical seal would be destroyed by the grit it cannot flush. A component mechanical seal leaks nothing when it is set correctly and is set by measurement in the field; a cartridge seal arrives pre-set on its own sleeve and is the seal most specifications now write for a rotary pump in sludge, because a plant mechanic can change it without a seal shop. A dual seal with a clean barrier or buffer fluid keeps the inner faces in a fluid that is not sludge, which is bought for a digested sludge pump whose leakage would release gas into the room, and it brings a barrier fluid system to maintain. Lip seals are the seals of small lobe pumps and of the intermediate chamber of a lobe pump gear case, and they are not a seal for pressure. (13.1.5)
NOTE Silicon carbide against silicon carbide is the pair most sludge seals are built with: both faces are harder than the grit, so nothing embeds, and silicon carbide carries heat away well enough to survive a brief dry start. Tungsten carbide against tungsten carbide is tougher against impact and is chosen where the fluid carries hard lumps, at a lower corrosion resistance in digested sludge. The mixed pair puts the toughness of tungsten carbide on one face and the heat conduction of silicon carbide on the other. Carbon against silicon carbide is the clean-liquid pair; it runs cooler and forgives a dry start, and it is lapped flat by any grit the fluid carries, which is why the clause above confines it to fluids without grit, such as polymer solution and residuals. (13.1.6)

13.2 Seal Flush and Packing Lubrication

13.2.1 The seal flush or packing lubrication arrangement shall be as indicated in the datasheet.
Seal Flush Arrangementradio
○ None, the seal or packing runs in the pumped fluid
○ Plant water flush through the lantern ring or seal chamber
○ Grease lubrication of the packing through the lantern ring
○ Barrier or buffer fluid system serving a dual seal
13.2.2 Where a plant water flush is furnished, the flush shall be supplied through a solenoid valve that opens when the pump runs, a flow indicator, a pressure regulator set above the seal chamber pressure, and a backflow preventer under Backflow PreventionBackflow PreventionResolves to the current adopted revision.sync/backflow-prevention, with the flush assembly mounted on the pump baseplate by the pump manufacturer.
13.2.3 Where compression packing is furnished, the stuffing box leakage shall be collected in a drip pan or gland drain piped to the nearest floor drain, and the operation and maintenance manual shall state the leakage rate the packing requires.
13.2.4 Where a dual seal is furnished, the barrier or buffer fluid reservoir, its level and pressure switches, and its connections shall be furnished by the pump manufacturer and mounted on the pump or its baseplate.
NOTE A seal running in sludge is the arrangement of most rotary sludge pumps with a cartridge seal of hard faces, and it works because the faces can take the grit; a water flush keeps the seal chamber clear of solids and cools the faces, and it dilutes the sludge by a few gallons per minute per pump, which a thickener or a digester downstream notices over a year. Grease through the lantern ring is the lubrication of packing on a plunger pump and keeps grit out of the packing rings. The flush solenoid is interlocked with the pump so that the flush does not run into a stopped pump, and the flow indicator is what tells the operator the flush has failed before the seal does. (13.2.5)

14 Drive Train

14.1 Drive Arrangement

14.1.1 The drive arrangement for each motor-driven pump shall be as indicated in the datasheet.
Drive Arrangementselect
Foot-mounted gear reducer coupled to the motor and to the pump on a common baseplate
Integral gearmotor flange-mounted to the pump
Shaft-mounted gear reducer on the pump shaft with a V-belt drive from the motor
V-belt drive from the motor to the pump without a reducer
Direct coupling from the motor to the pump without a reducer
Hydraulic motor drive from a separate hydraulic power unit
14.1.2 Gear reducers shall be enclosed helical or helical-bevel units rated under ANSI/AGMA 6013, with the output torque rating and the thermal rating stated in the submittal, and with the service factor applied to the motor nameplate horsepower not less than the value indicated in the datasheet.
Gear Reducer Service Factorrange
11.251.51.752
14.1.3 Gear reducer bearings shall be selected for a rating life under ANSI/ABMA 9 or ANSI/ABMA 11 of not less than the value indicated in the datasheet at the rated speed and the torque at the relief device set pressure.
Gear Reducer Bearing Rating Liferange
hours
1000017500250004000050000100000
14.1.4 Gear reducers shall be furnished with an oil level sight gauge, a fill and breather, a drain reachable with the pump installed, and the oil the manufacturer specifies for the installed orientation.
NOTE A foot-mounted reducer with couplings at both ends is the drive of a large sludge pump: every element is a standard catalog unit, each is replaced alone, and the baseplate carries the alignment. An integral gearmotor bolts the motor to the reducer and the reducer to the pump with no coupling to align, which is the drive of most small and medium progressive cavity and lobe pumps and costs a reducer that is specific to the pump. A shaft-mounted reducer hangs on the pump shaft with a belt from a motor beside it, which is the drive of a plunger pump and of a pump whose speed the plant wants to change by swapping a sheave. A belt alone, without a reducer, serves a lobe pump or a plunger pump at a ratio a single belt drive can carry. Direct coupling at motor speed suits only a pump designed to run at 1200 or 1800 RPM, such as a small lobe pump on polymer. A hydraulic drive moves the motor and its enclosure out of the pit and delivers very high torque at very low speed, which is the drive of a cake pump feeding a long pipeline, and it brings a hydraulic power unit to maintain. (14.1.5)
NOTE A service factor of 1.5 on the motor nameplate is the reducer rating most sludge pump specifications carry for a progressive cavity or lobe pump on a drive, and 1.75 to 2.0 is written for a plunger pump, whose torque pulses with each stroke, and for a pump started across the line against a full line. A factor of 1.0 or 1.25 is a position for a continuous, uniform load such as a polymer pump. The bearing life numbers follow the same logic, with 25,000 hours a common floor for a continuous-duty reducer and 50,000 or more written where the Owner expects the reducer to outlast two pumps. (14.1.6)

14.2 Speed Control

14.2.1 Speed control for each pump shall be as indicated in the datasheet.
Speed Controlradio
○ Constant speed
● Variable frequency drive
○ Mechanical variable-speed belt drive
○ Hydraulic variable-speed drive
14.2.2 Where a variable frequency drive is selected, the pump shall deliver the rated capacity at the rated speed and shall be rated for continuous operation down to the minimum speed set by the turndown ratio indicated in the datasheet, at the full rated discharge pressure.
Speed Turndown Ratiorange
123456810
14.2.3 Where a variable frequency drive is selected, the drive shall be furnished under Low Voltage Variable Frequency DrivesLow-Voltage Variable Frequency DrivesResolves to the current adopted revision.sync/low-voltage-variable-frequency-drives or Motor Control CentersMotor Control CentersResolves to the current adopted revision.sync/motor-control-centers with its constant-torque overload rating, and the motor shall be rated for constant torque across the turndown indicated, with a separately powered cooling blower where the motor manufacturer requires one at the minimum speed.
14.2.4 Where a variable frequency drive is selected, the drive shall be set with a minimum speed limit at the turndown indicated, and the pump manufacturer shall state the minimum speed below which the pump is not rated for continuous operation on the pumped fluid.
14.2.5 Where a mechanical variable-speed belt drive is selected, the drive shall be furnished with a handwheel or electric actuator for speed adjustment, a speed indicator, and belts rated for the full motor torque at the lowest speed.
14.2.6 Where a belt drive is furnished, the belts shall be V-belts or synchronous belts on sheaves rated for not less than 1.5 times the motor nameplate horsepower, with the sheaves and belts guarded under 29 CFR 1910.219.
NOTE A positive displacement pump meters by speed, and a drive is the way the operator sets the sludge withdrawal rate from the control room rather than at a valve, which is why a drive is now specified on nearly every sludge pump and is the default. The load is constant torque: the pump needs the same torque at 10 percent speed as at 100 percent because the pressure is the same, so the drive is sized on its constant-torque rating and the motor needs cooling it does not get from its own fan at low speed. A mechanical variable-speed drive does the same job with a belt and a variable-pitch sheave, needs no drive electronics or inverter-duty motor, and is adjusted at the pump; a hydraulic drive varies speed by displacement and is the choice where the drive is already hydraulic. Constant speed is the position for a pump that runs on a level or a timer, such as a scum pump, and for a plunger pump with an adjustable stroke. (14.2.7)
NOTE A turndown of four to one is what most sludge feed duties use, so that a pump sized for the peak day can match the average day; ten to one is written for a digester feed or a dewatering feed pump that trims to a process setpoint, and it demands a motor the manufacturer rates for 10 percent speed. A ratio of one is a constant-speed pump and leaves the field consistent with that selection. (14.2.8)

14.3 Coupling

14.3.1 Couplings between the motor and the reducer and between the reducer and the pump shall be of the type indicated in the datasheet, selected by the pump manufacturer for the torque at the relief device set pressure, the starting method, and the misalignment the installation can produce.
Coupling Typeselect
Elastomeric jaw coupling
Elastomeric tire coupling
Grid coupling
Metallic disc coupling
Rigid flanged coupling
Not applicable, integral gearmotor without a coupling
14.3.2 The coupling between the reducer and the pump shall include a spacer or shall be arranged so that the shaft seal can be changed without moving the reducer or the motor.
14.3.3 Couplings shall be guarded under Common Work Results ProcessCommon Work Results for Process EquipmentResolves to the current adopted revision.sync/common-work-results-process, and the guard shall be removable without disturbing the alignment.
NOTE An elastomeric jaw or tire coupling absorbs the torque pulses of a plunger pump and the starting shock of a pump that starts against a full line, isolates the motor electrically from the pump, and wears its element, which is inspected through the guard. A grid coupling carries more torque in the same diameter and damps torsional vibration through its spring grid, which is why it is the coupling of large plunger pumps. A metallic disc coupling has no wear element and no damping and is chosen where a long life without maintenance matters more than shock absorption. A rigid coupling is used only between a reducer and a pump that share a rigid frame. (14.3.4)

15 Pump Motor

15.1 Motor Rating

15.1.1 The motor for each pump shall be furnished under Electric MotorsCommon Motor Requirements for Electrical EquipmentResolves to the current adopted revision.sync/electric-motors, rated at the nameplate horsepower indicated in the datasheet, for continuous duty.
Motor Nameplate Horsepowerrange
hp
0.50.7511.52357.5101520253040506075100125150200250
Per drawings — the pump schedule and the motor schedule (deferred by default)
15.1.2 The motor service factor shall be as indicated in the datasheet.
Motor Service Factorrange
11.151.25
Default: Not less than 1.15
15.1.3 The motor nameplate horsepower shall equal or exceed the brake horsepower of the pump at the relief device set pressure, at the maximum speed, on the pumped fluid at its highest viscosity, with the reducer and belt losses added and without using the service factor.
15.1.4 The motor design letter shall be selected under Electric MotorsCommon Motor Requirements for Electrical EquipmentResolves to the current adopted revision.sync/electric-motors so that the starting torque exceeds the breakaway torque of the pump with the pumping elements wetted and the discharge line full, at the reduced torque a soft starter or drive delivers where one is furnished.
15.1.5 Where a variable frequency drive is selected under this standard, the motor shall be rated for inverter duty under NEMA MG 1 Part 31 and for constant torque across the speed turndown indicated.
NOTE A positive displacement pump does not run out, so the motor is sized at the pressure the relief device allows rather than at a runout point, and that pressure is the rated pressure plus the relief margin. A progressive cavity pump with a new stator has an interference fit that demands two or three times its running torque to break away, and a plunger pump starting against a full line sees its full stroke torque on the first revolution, which is why the design letter is a selection rather than an assumption; a drive softens both starts. (15.1.6)

15.2 Motor Enclosure

15.2.1 The motor enclosure shall be as indicated in the datasheet.
Motor Enclosureselect
Totally enclosed fan cooled, TEFC
Totally enclosed fan cooled, severe duty with corrosion-resistant finish
Totally enclosed nonventilated, TENV
Totally enclosed blower cooled, TEBC
Open drip proof, ODP
Explosionproof
Washdown duty
15.2.2 Where the motor is installed outdoors, the enclosure shall be totally enclosed with a drain and breather at its low point.
15.2.3 Where the motor is installed in a location classified under NFPA 820 or NFPA 70 Articles 500 through 504, the enclosure shall be listed for the class, division, and group of that location.
15.2.4 Where the motor is installed in a washdown area, the enclosure shall be of washdown construction with sealed bearings and a gasketed conduit box.

16 Discharge Relief and Pressure Protection

16.1 Relief Device

16.1.1 Each pump shall be furnished with a relief device on the discharge side, located between the pump discharge connection and the first valve in the discharge piping, with no valve between the pump and the relief device.
16.1.2 The relief device shall be of the type indicated in the datasheet.
Discharge Relief Deviceradio
○ External spring-loaded relief valve
○ Rupture disc in a holder with a burst indicator
○ Internal relief valve within the pump body
○ High-pressure shutdown only, without a mechanical relief device
16.1.3 Where a relief valve or rupture disc is furnished, its discharge shall be piped to the destination indicated in the datasheet.
Relief Discharge Destinationradio
○ The pump suction, upstream of the suction isolation valve
○ The feed tank, hopper, or wet well the pump draws from
○ A drain or containment
16.1.4 The relief device shall be set to open at the rated discharge pressure plus the margin indicated in the datasheet, and the set pressure shall not exceed the pressure rating of the pump casing, the stator tube, or the discharge piping.
Relief Set Pressure Margin Above Rated Discharge Pressurerange
%
10152025304050
16.1.5 A relief valve shall pass the full rated capacity of the pump at the set pressure with not more than 10 percent rise in pressure, shall be of a design the manufacturer rates for the pumped fluid at its solids content, and shall be bench-set and sealed at the factory with the set pressure stamped on its nameplate.
16.1.6 Where a rupture disc is furnished, the burst indicator shall stop the pump and alarm, and spare discs shall be furnished in the quantity indicated in the datasheet for each size and rating installed.
Spare Rupture Discs per Sizerange
discs
23461012
16.1.7 Where the discharge piping of two or more pumps joins a common header, each pump shall have its own relief device upstream of its discharge check valve.
NOTE A positive displacement pump against a closed valve raises the discharge pressure until something yields, and within seconds the something is the stator tube, a flange gasket, the reducer, or the motor overload, which is why the relief device sits between the pump and the first valve with nothing in between. An external relief valve resets itself and returns the flow, so a closed valve costs nothing but a warm pump, and in sludge it needs a design whose seat is not packed with grit on the first lift; a rupture disc has no moving part to foul and opens once, after which the pump is down until the disc is changed, which is why it carries a burst indicator and spares. An internal relief valve is a feature of some lobe and diaphragm pumps and relieves within the body, so the pump churns its own fluid and heats it. Shutdown only, on a pressure switch, is a position some projects take on a progressive cavity pump in a short line with a drive, on the reasoning that the switch trips faster than the pressure rises; it leaves nothing in place when the switch fails. (16.1.8)
NOTE Returning the relief flow to the suction is the compact arrangement and works for a brief relief, since the pump heats the recirculated fluid on every pass and a sustained relief returns hot sludge to its own inlet; returning to the feed tank or the wet well dissipates the heat and the pressure in the volume there and is the arrangement of a pump that can be left relieving; a drain is the arrangement of a hose pump or a chemical duty where the relief flow is small and the fluid is not worth recovering. A margin of 10 to 25 percent above the rated pressure keeps the relief device from weeping at the rated point while holding the casing and the drive within rating; 50 percent is a position for a cake pipeline whose pressure swings widely as the cake dries. (16.1.9)

16.2 High-Pressure Shutdown

16.2.1 Each pump shall be furnished with the high-pressure protection indicated in the datasheet, set below the relief device set pressure, which shall stop the pump through a hardwired interlock and shall alarm to the plant control system under Control Systems IntegrationControl Systems Integration and TestingResolves to the current adopted revision.sync/control-systems-integration.
High-Pressure Protectionradio
○ Pressure switch on the discharge, wired to stop the pump
○ Pressure transmitter on the discharge, with the shutdown executed in the plant control system
○ Pressure switch for shutdown and pressure transmitter for indication
16.2.2 The pressure switch or transmitter shall be furnished with the pump, mounted on the discharge between the pump and the relief device, isolated from the pumped fluid by a diaphragm seal with a flushing connection, and tagged and integrated under Process InstrumentationProcess InstrumentationResolves to the current adopted revision.sync/process-instrumentation and Control Systems IntegrationControl Systems Integration and TestingResolves to the current adopted revision.sync/control-systems-integration.
16.2.3 A high-pressure trip shall lock out the pump until it is reset locally, and the pump shall not restart automatically after a high-pressure trip.
NOTE A switch wired straight into the starter or the drive trips without depending on a controller, a network, or a program, which is why it is the protection most specifications write; a transmitter gives the operator the trend that shows a line slowly plugging weeks before the trip, and a shutdown executed in the controller is only as fast and as reliable as the controller. Furnishing both, the switch for the trip and the transmitter for the trend, is the position of a plant that runs its sludge pumps from a control room. The diaphragm seal is what keeps a sludge pressure tap from plugging within the first month. (16.2.4)

17 Connections, Casing, and Piping Interface

17.1 Connections and Casing Material

17.1.1 The suction and discharge connections shall be of the type indicated in the datasheet, rated for the relief device set pressure.
Pump Connection Typeselect
Flanged, ASME B16.1 Class 125
Flanged, ASME B16.1 Class 250
Flanged, ASME B16.42 Class 150
Flanged, ASME B16.42 Class 300
Flanged, ASME B16.5 Class 150
Flanged, ASME B16.5 Class 300
Grooved end
Threaded, NPT
17.1.2 The pump casing, suction housing, and pump chamber shall be of the material indicated in the datasheet.
Pump Casing Materialselect
Cast iron
Ductile iron
Type 316 stainless steel casting
Duplex stainless steel casting
17.1.3 Cast iron castings shall conform to ASTM A48/A48M, Class 30 or higher, ductile iron castings to ASTM A536, and stainless steel castings to ASTM A743/A743M for the grade furnished.
17.1.4 Exposed fasteners on the pump, the baseplate, and the drive train shall be Type 316 stainless steel, and fasteners on the gear reducer and motor shall be the manufacturers' standard with a corrosion-resistant finish.
17.1.5 The orientation of the suction and discharge connections shall be as shown on the process mechanical plans and sections.
NOTE Class 125 iron flanges match the flanged ductile iron sludge piping of most plants and cover rated pressures to 175 psi at the pump, which is where most sludge duties fall; Class 250 iron and Class 300 steel or ductile iron flanges are needed on a plunger or cake pump whose relief pressure exceeds the lower class, and the discharge of such a pump is often one class higher than its suction. Grooved and threaded connections are the connections of small and portable pumps. A cast iron casing is the casing of nearly every sludge pump, which is why it is the default; ductile iron is chosen for the higher-pressure casings and where the pump is subject to impact; a stainless casing is bought for digested or chemical sludge, septage with a high chloride content, and polymer, and duplex for the most corrosive of those. (17.1.6)

17.2 Flushing and Cleanout Connections

17.2.1 Each pump shall be furnished with the flushing and cleanout connections indicated in the datasheet, each located between the pump and its isolation valves, and the piping, valves, and backflow protection serving them shall be furnished under the piping standards and Backflow PreventionBackflow PreventionResolves to the current adopted revision.sync/backflow-prevention.
Flushing and Cleanout Connectionscheckbox
☑ Suction-side cleanout with a blind flange or capped tee
☑ Discharge-side cleanout with a blind flange or capped tee
☑ Plant water flushing connection on the suction side
☑ Plant water flushing connection on the discharge side
☑ Suction and discharge pressure gauge connections with isolation valves and diaphragm seals
☐ Sampling tap on the discharge
17.2.2 Flushing connections shall be sized not smaller than 1 in., and cleanouts shall be the full size of the connecting pipe up to 4 in. and not smaller than 4 in. on larger pipe.
NOTE A sludge line is cleared by flushing it with plant water or by rodding it through a cleanout, and both have to be reachable with the pump isolated, which is why the connections sit between the pump and its valves. The flushing connections are defaulted because a sludge pump that cannot be flushed before a shutdown is a pump whose stator is cast in dried sludge when it is next started. (17.2.3)

17.3 Suction and Discharge Piping Arrangement

17.3.1 The suction piping shall be not smaller than the pump suction connection and shall be arranged with no reduction in size, no high point that traps gas, and the fewest fittings the layout allows between the source and the pump, as shown on the process mechanical plans and sections.
17.3.2 The suction and discharge piping shall be supported and anchored under the piping standards so that no load from the piping, including the pulsation load of a reciprocating pump, is carried by the pump connections.
17.3.3 Where flexible connectors are furnished at the pump connections under Vibration Isolation And Seismic RestraintVibration Isolation and Seismic RestraintResolves to the current adopted revision.sync/vibration-isolation-and-seismic-restraint, they shall be rated for the relief device set pressure and for the pumped fluid, and they shall be restrained against the pressure thrust.
17.3.4 Where a discharge check valve is furnished under Process Check ValvesProcess Check ValvesResolves to the current adopted revision.sync/process-check-valves, it shall be installed downstream of the relief device and the pressure protection.
17.3.5 Where the pump is a reciprocating pump or a hose pump, the discharge piping between the pump and any flow meter under Flow MeasurementFlow MeasurementResolves to the current adopted revision.sync/flow-measurement shall include the pulsation dampener selected under this standard or a straight run the meter manufacturer accepts for the pulsation.
NOTE The suction line of a positive displacement pump is where its capacity is won or lost: a sludge pump pulls a vacuum on a line that is too long or too small until gas comes out of the sludge and fills the cavities, and the pump then delivers a fraction of its displacement while turning at full speed. A check valve belongs downstream of the relief device, because a check valve between the pump and the relief device is a valve that can close against the pump. (17.3.6)

17.4 Cake Feed Hopper

17.4.1 Where the pump is fed dewatered solids, the hopper and feed arrangement shall be as indicated in the datasheet and shall be furnished by the pump manufacturer as part of the pump unit.
Cake Feed Hopper Arrangementradio
○ Not required, the pump draws liquid sludge
○ Hopper with a single feed auger
○ Hopper with twin feed augers
○ Hopper with a feed auger and a bridge breaker
○ Hopper with a feed auger and a boundary layer injection ring on the discharge
17.4.2 The hopper shall be of Type 304 or Type 316 stainless steel, flanged to receive the dewatering equipment discharge or conveyor at the elevation shown on the process mechanical sections, and shall be furnished with a level switch or transmitter that stops the pump on low level.
17.4.3 The feed auger shall be driven by its own gear reducer and motor, interlocked to run with the pump, with the auger speed selected by the manufacturer for the cake solids content and the pump displacement.
17.4.4 Where a boundary layer injection ring is furnished, it shall inject the lubricant the manufacturer specifies, typically polymer solution or water, through a ring at the pump discharge at a rate the manufacturer states, with the injection pump and its controls furnished with the pump unit.
NOTE Dewatered cake does not flow into a pump; it bridges across the hopper and has to be forced into the suction. A single auger serves a narrow hopper fed from one point, twin augers sweep a wider hopper under a belt press or a centrifuge discharge, and a bridge breaker is an arm that rotates above the auger to collapse a bridge in a tall hopper of sticky cake. A boundary layer injection ring coats the pipe wall with a thin film of lubricant so that the cake slides on it, which can cut the pipeline pressure by more than half on a long run and is what makes a pipeline of several hundred feet practical. (17.4.5)

18 Baseplate and Mounting

18.1 The pump, the reducer, and the motor shall be mounted on a common baseplate of the type indicated in the datasheet, stiff enough that the alignment set at the factory holds under the torque at the relief device set pressure.
Baseplate Typeselect
Fabricated carbon steel baseplate, shop coated
Fabricated Type 304 stainless steel baseplate
Fabricated Type 316 stainless steel baseplate
Cast iron baseplate
Structural steel skid without grout, for a skid-mounted or portable pump
Not applicable, vertical close-coupled or hopper-mounted pump
18.2 The baseplate shall be furnished with grout holes, vent holes, a grout dam, leveling screws or shims, and anchor bolt holes, and shall be grouted under Common Work Results ProcessCommon Work Results for Process EquipmentResolves to the current adopted revision.sync/common-work-results-process unless a skid without grout is selected.
18.3 The baseplate shall be furnished with a drip rim and a drain connection where compression packing or a water flush is selected, so that leakage is collected and piped to a drain rather than spread on the floor.
18.4 Where the pump is a reciprocating pump, the baseplate and its anchorage shall be designed by the manufacturer for the unbalanced forces and moments of the pump at the rated stroke rate, and those forces shall be stated on the baseplate drawing.
18.5 Where the pump is mounted vertically, the pump shall be supported on a stand or a floor flange furnished by the manufacturer, with the drive above the pump and a drain below the seal.
18.6 Coupling alignment shall be verified in the field after grouting and again after the first run at operating temperature, within the coupling manufacturer's published tolerance, and both readings shall be recorded in the startup report.

19 Factory Testing

19.1 Performance Test

19.1.1 Each pump shall receive the factory performance test indicated in the datasheet, conducted on water under ANSI/HI 3.6 for a progressive cavity, rotary lobe, or hose pump, ANSI/HI 6.6 for a plunger or piston pump, and ANSI/HI 10.6 for an air-operated pump.
Factory Performance Testradio
○ Certified performance test of every pump at the rated speed and the rated and relief pressures
○ Certified performance test of one pump of each size, with the manufacturer's production test on the others
○ Manufacturer's production test with the certified catalog curve
19.1.2 The performance test shall record the capacity, the slip, the speed, and the input power at the rated differential pressure and at the relief device set pressure, and for a variable-speed pump at the minimum speed as well.
19.1.3 The measured capacity at the rated speed and the rated differential pressure, corrected to the pumped fluid by the manufacturer's stated correction, shall be not less than the rated capacity, within the acceptance tolerance the applicable Hydraulic Institute test standard assigns.
19.1.4 A pump that fails the performance test shall be corrected and retested at the manufacturer's cost before shipment, and the witnessing of the test shall be on the basis selected under Common Work Results ProcessCommon Work Results for Process EquipmentResolves to the current adopted revision.sync/common-work-results-process.
NOTE Testing every pump catches the stator that was molded undersize or the lobes that were timed wrong, and it is the basis most specifications write for a sludge pump above a few horsepower; testing one of each size trusts the manufacturer's process for the rest and halves the test cost on a project with many identical pumps; the production test alone is the position for small standard pumps and for a hose or diaphragm pump, whose capacity is a function of the hose or diaphragm and the air pressure rather than of a machined clearance. (19.1.5)

19.2 Hydrostatic and Component Tests

19.2.1 Each pump casing, suction housing, stator tube, and pump chamber shall be hydrostatically tested at the factory at 1.5 times the relief device set pressure for not less than 10 minutes with no leakage.
19.2.2 Each relief valve shall be bench-tested at the factory to the set pressure, sealed, and certified, and each rupture disc lot shall be certified by the disc manufacturer for its burst rating.
19.2.3 Each assembled pump and drive train shall be run at the factory to verify rotation, freedom from abnormal noise, and the operation of the dry-run device, the hose leak detector, and the high-pressure switch where those devices are furnished with the pump.
19.2.4 The dimensional record of the wear parts required under the closeout submittals shall be taken at the factory before the pump is assembled for shipment.

20 Field Testing

20.1 After startup under Common Work Results ProcessCommon Work Results for Process EquipmentResolves to the current adopted revision.sync/common-work-results-process, each pump shall be field tested on the pumped fluid at the rated speed, and the Contractor shall record the capacity, measured by the flow meter under Flow MeasurementFlow MeasurementResolves to the current adopted revision.sync/flow-measurement or by drawdown of the feed tank, together with the discharge pressure, the suction pressure or vacuum, the speed, and the motor current.
20.2 The measured capacity shall be plotted against the certified curve corrected for the pumped fluid, and the field performance test basis and tolerance shall be as selected under Common Work Results ProcessCommon Work Results for Process EquipmentResolves to the current adopted revision.sync/common-work-results-process.
20.3 For a variable-speed pump, the field test shall be repeated at the minimum speed set by the turndown ratio, and the pump shall deliver a steady flow at that speed without stalling or surging.
20.4 The dry-run device, the hose leak detector, and the high-pressure switch shall each be tripped by simulation during the field test, and the lockout and alarm of each shall be recorded.
20.5 Where an external relief valve is furnished, its operation shall be demonstrated by slowly closing the discharge isolation valve with the manufacturer's representative present, and the pressure at which the valve opens shall be recorded and compared with the set pressure; where a rupture disc is furnished, the demonstration shall stop at the high-pressure shutdown.
20.6 Vibration acceptance of each pump shall be on the manufacturer's published field acceptance limits basis under Common Work Results ProcessCommon Work Results for Process EquipmentResolves to the current adopted revision.sync/common-work-results-process, because the Hydraulic Institute vibration standard for rotodynamic pumps does not cover a positive displacement pump.
20.7 Where the plant cannot supply the pumped fluid at the design solids content at the time of the test, the test shall be run on the fluid available, the solids content shall be measured and recorded, and the capacity shall be corrected to the design solids content by the manufacturer's stated correction.
NOTE A sludge pump tested on water performs on water, and the number the Owner needs is the capacity on sludge at the solids content the plant actually makes, which is why the field test is run on the process fluid and the relief valve is proved against a real line. Closing the discharge on a pump with only a rupture disc proves nothing but the disc, which is why that demonstration stops at the switch. (20.8)

21 Shop Coating

21.1 Ferrous surfaces of the pump, the reducer, and the baseplate that are not wetted and not machined shall be shop coated with the system indicated in the datasheet, and stainless steel and nonferrous surfaces shall be left uncoated.
Shop Coating Systemradio
○ Epoxy primer and epoxy finish over SSPC-SP 6 blast cleaning
○ Epoxy primer over SSPC-SP 6 blast cleaning, finish coated in the field
○ Epoxy primer and polyurethane finish over SSPC-SP 10 blast cleaning
Manufacturer's standard (by default)
21.2 Where the pump is finish coated in the field, the finish coat shall be applied under High Performance CoatingsHigh-Performance CoatingsResolves to the current adopted revision.sync/high-performance-coatings with a system compatible with the shop primer, and the pump manufacturer shall state the primer and its recoat window in the submittal.
21.3 Machined surfaces, shafts, and the interior of a cast iron casing shall be protected for shipment with a removable rust preventive.
21.4 Shop coating damaged in shipment or installation shall be repaired by the Contractor with the same system before the pump is accepted.

22 Delivery, Storage, and Handling

22.1 Stators, hoses, elastomer-covered lobes, and diaphragms shall be stored in a dark, cool, dry space away from ozone sources, electric motors, and sunlight, for not longer than the shelf life the elastomer manufacturer publishes before installation.
22.2 A progressive cavity pump stored longer than the period the manufacturer permits with the rotor in the stator shall have the rotor withdrawn or the stator removed and stored separately, and the condition shall be logged in the storage record required under Common Work Results ProcessCommon Work Results for Process EquipmentResolves to the current adopted revision.sync/common-work-results-process.
22.3 Hose pumps shall be shipped and stored with the hose relaxed and the shoes or rollers rotated clear of the hose, or with the hose removed, as the manufacturer instructs.
22.4 Gear reducers shall be shipped with the oil the manufacturer specifies for shipment, and the shipping oil shall be drained and replaced with the operating oil at the installed orientation before the first run.
NOTE An elastomer that sits compressed under a rotor for a year takes a set at the contact line and the pump starts with a leak path already in it; a hose left under a shoe does the same thing in weeks. Both are visible only after startup, as a capacity that never reaches the curve. (22.5)

23 Warranty

23.1 The pump warranty period and coverage shall be as required under Common Work Results ProcessCommon Work Results for Process EquipmentResolves to the current adopted revision.sync/common-work-results-process, and the wear parts named below shall be warranted against defects in materials and workmanship for not less than the period indicated in the datasheet from the date of substantial completion.
Wear Parts Warranty Periodrange
months
612182436
23.2 The wear parts for the purpose of the warranty are the stator and rotor, the lobes and wear plates, the plungers, packing, and ball checks, the hose, and the diaphragms.
23.3 The warranty shall not exclude wear from abrasion unless the manufacturer stated in the submittal the solids content and the abrasive content for which the wear parts were selected, and the pumped fluid is shown to have exceeded them.
23.4 The warranty shall exclude damage from dry running only where the dry-run protection selected under this standard was furnished, interlocked, and demonstrated, and was defeated or bypassed by the Owner.
NOTE A manufacturer warrants a stator against a bonding failure or a bad mold, not against the sludge wearing it out, and a warranty written without stating what the stator was selected for lets every failure be called wear. Stating the design solids and abrasive content in the submittal is what makes a premature failure a claim; the dry-run clause works the same way in the other direction. (23.5)

24 Spare Parts

24.1 The spare parts indicated in the datasheet shall be furnished for each pump size and type installed, in addition to the spare parts basis selected under Common Work Results ProcessCommon Work Results for Process EquipmentResolves to the current adopted revision.sync/common-work-results-process.
Spare Parts Furnishedcheckbox
☐ One stator for each progressive cavity pump size
☐ One rotor for each progressive cavity pump size
☐ One set of drive joint seals, sleeves, bands, and lubricant for each progressive cavity pump size
☐ One set of lobes for each rotary lobe pump size
☐ One set of wear plates for each rotary lobe pump size
☐ One set of plungers for each plunger pump size
☐ One set of check valve balls and seats for each plunger pump size
☐ Two hoses for each hose pump size, with inserts and lubricant
☐ One set of diaphragms and check valves for each diaphragm pump size
☐ One mechanical seal or one set of packing for each pump size
☐ One set of gaskets and O-rings for each pump size
☐ One relief valve for each size and set pressure installed
24.2 Spare parts shall be the products of the pump manufacturer, packaged for long-term storage in the condition the storage article of this standard requires for elastomers, and labeled with the pump equipment number, the pump model, and the manufacturer's part number.
24.3 The Contractor shall furnish one set of the special tools the manufacturer's manual identifies for stator removal, rotor withdrawal, lobe removal, hose replacement, or ball check extraction, labeled with the equipment numbers they serve.
NOTE The stator, the hose, and the lobes are consumables with a life measured in months to a few years in sludge, and a plant that has one on the shelf changes it in a morning; a plant that has to order one runs on its standby pump for the weeks it takes to arrive, and on many plants the standby is one pump for the service. The list carries no default because the parts a project needs follow the pump types it selects. (24.4)