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Butterfly Valves

Rev1
IssuedOct 12, 2026
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1 Scope

NOTE The boundary of the work is the valve as a shop-assembled unit: the body and its end connections, the seat and the disc, the shaft, bearings, and shaft seals, the manual operator or the mounting interface for a power actuator, the shop coating, and the tests that prove the unit before it ships, together with the installation and field tests that prove it in the line. (1.2)
NOTE A butterfly valve on a plant main is operated a few times a year and is expected to seal drop-tight each time for decades, usually against a differential pressure it has never seen in service until the day a section is drained. The parts that fail are the ones nobody sees: a seat that has taken a set, a shaft bearing that has seized in grit, an operator sized for a pressure the plant exceeded. That is why this standard is prescriptive about the class rating, the seating surfaces, the operator sizing, and the shop tests, and permissive about the body style, materials, and operator type the engineer legitimately selects by location. (1.3)
NOTE The AWWA standards divide butterfly valves by size: AWWA C504 covers 3 in. through 72 in., and AWWA C516 covers 78 in. and larger. Both describe a concentric, rubber-seated valve rated by class for a differential pressure and a flow velocity. MSS SP-67 and API 609 describe the resilient-seated and high-performance valves of industrial piping, which this standard admits where a size below 3 in. or a service outside water and wastewater calls for them. (1.4)
1.5 Valves shall conform to the design standard selected in the datasheet and shall be rated for the pressure class indicated for each valve on the valve schedule.
1.6 Valves in potable water service shall be certified to NSF/ANSI/CAN 61 and NSF/ANSI/CAN 372 for every wetted component, including the seat, the coating, and the lubricants.
NOTE A butterfly valve in a modulating control loop is a control valve and is furnished under Control Valves And ActuatorsControl Valves and ActuatorsResolves to the current adopted revision.sync/control-valves-and-actuators. The electric, pneumatic, or hydraulic actuator on a butterfly valve that opens and closes for isolation, with its position signals, is furnished under Valve And Gate ActuatorsValve and Gate ActuatorsResolves to the current adopted revision.sync/valve-and-gate-actuators. This standard furnishes the valve body such an actuator is mounted on, the mounting interface, and the torque data the actuator is sized from. (1.7)
NOTE The following are outside this scope and are governed by the companion standards named. (1.8)
  • Modulating control valves with their actuators and positioners: Control Valves And ActuatorsControl Valves and ActuatorsResolves to the current adopted revision.sync/control-valves-and-actuators; actuators, floor stands, and exposed extension stems on isolation valves: Valve And Gate ActuatorsValve and Gate ActuatorsResolves to the current adopted revision.sync/valve-and-gate-actuators
  • Eccentric plug valves for raw water, wastewater, and sludge: Eccentric Plug ValvesEccentric Plug ValvesResolves to the current adopted revision.sync/eccentric-plug-valves
  • General-duty valves in building hydronic piping: HVAC Piping ValvesGeneral-Duty Valves for HVAC PipingResolves to the current adopted revision.sync/hvac-piping-valves
  • General-duty valves in domestic water piping: Plumbing Piping ValvesGeneral-Duty Valves for Plumbing PipingResolves to the current adopted revision.sync/plumbing-piping-valves
  • Fire protection control valves listed to UL 1091: Fire Protection PipingFire Protection Piping and SpecialtiesResolves to the current adopted revision.sync/fire-protection-piping
  • The process piping, its flange bolting and gaskets, and its pressure test: 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, and Plastic Process PipingPlastic Process PipingResolves to the current adopted revision.sync/plastic-process-piping
  • Buried site distribution mains and the valve boxes on them: Water Distribution PipingSite Water Distribution PipingResolves to the current adopted revision.sync/water-distribution-piping
  • Common process administrative and execution provisions: Common Work Results ProcessCommon Work Results for Process EquipmentResolves to the current adopted revision.sync/common-work-results-process
  • Field-applied finish coat systems: High Performance CoatingsHigh-Performance CoatingsResolves to the current adopted revision.sync/high-performance-coatings
  • Valve tags and piping identification: Mechanical IdentificationMechanical IdentificationResolves to the current adopted revision.sync/mechanical-identification
NOTE The other process valve types are governed by Resilient Seated Gate ValvesResilient-Seated Gate ValvesResolves to the current adopted revision.sync/resilient-seated-gate-valves, Process Check ValvesProcess Check ValvesResolves to the current adopted revision.sync/process-check-valves, and Air Release And Vacuum ValvesAir Release and Vacuum ValvesResolves to the current adopted revision.sync/air-release-and-vacuum-valves; power operators and floor stands by Valve And Gate ActuatorsValve and Gate ActuatorsResolves to the current adopted revision.sync/valve-and-gate-actuators; slide gates by Slide Gates And Stop LogsSlide Gates and Stop LogsResolves to the current adopted revision.sync/slide-gates-and-stop-logs. (1.9)

2 Referenced Standards

2.1 Valves, materials, and installation shall comply with the latest adopted edition of each of the following unless a specific edition is cited.
2.2 Where the contract documents, the adopted codes, or a referenced standard conflict, the more stringent requirement shall govern unless the Engineer of Record directs otherwise in writing.
Standard Title
AWWA C504 Rubber-Seated Butterfly Valves, 3 In. Through 72 In.
AWWA C516 Large-Diameter Rubber-Seated Butterfly Valves, Sizes 78 In. and Larger
AWWA C550 Protective Interior Coatings for Valves and Hydrants
AWWA C541 Hydraulic and Pneumatic Cylinder and Vane-Type Actuators for Valves and Slide Gates
AWWA C542 Electric Motor Actuators for Valves and Slide Gates
AWWA C111/A21.11 Rubber-Gasket Joints for Ductile-Iron Pressure Pipe and Fittings
AWWA C606 Grooved and Shouldered Joints
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 B16.10 Face-to-Face and End-to-End Dimensions of Valves
ASME B16.42 Ductile Iron Pipe Flanges and Flanged Fittings: Classes 150 and 300
MSS SP-25 Standard Marking System for Valves, Fittings, Flanges, and Unions
MSS SP-67 Butterfly Valves
MSS SP-101 Part-Turn Valve Actuator Attachment: Flange and Driving Component Dimensions and Performance Characteristics
ISO 5211 Industrial Valves: Part-Turn Actuator Attachments
API 598 Valve Inspection and Testing
API 609 Butterfly Valves: Double-Flanged, Lug- and Wafer-Type
ASTM A126 Gray Iron Castings for Valves, Flanges, and Pipe Fittings
ASTM A276 / A276M Stainless Steel Bars and Shapes
ASTM A536 Ductile Iron Castings
ASTM A564 / A564M Hot-Rolled and Cold-Finished Age-Hardening Stainless Steel Bars and Shapes
ASTM A743 / A743M Castings, Iron-Chromium, Iron-Chromium-Nickel, Corrosion Resistant, for General Application
ASTM B148 Aluminum-Bronze Sand Castings
ASTM D429 Rubber Property: Adhesion to Rigid Substrates
ASTM D2240 Rubber Property: Durometer Hardness
NSF/ANSI/CAN 61 Drinking Water System Components: Health Effects
NSF/ANSI/CAN 372 Drinking Water System Components: Lead Content

3 Submittals

3.1 Action Submittals

3.1.1 The Contractor shall submit the following for the Engineer of Record's review and return before any butterfly valve is released for manufacture:
  • Product data for each valve size, class, body style, and service, identifying the design standard, the pressure class, the body, disc, shaft, seat, seating surface, bearing, and shaft seal materials with their ASTM designations, and the laying length
  • Dimensioned drawings for each valve showing the end connections and flange drilling, the shaft orientation, the operator or actuator mounting position, the handwheel or nut location, the position indicator, and the clearance the disc sweeps beyond the body faces when open
  • Operator data for each manually operated valve, identifying the operator type, the gear ratio, the number of turns to close, the input effort at the class rating, and, for buried valves, the operating nut and the extension stem length
  • Torque data for each valve to be power actuated, stating the seating, unseating, and dynamic torque at the class differential pressure and velocity and the maximum shaft torque the valve withstands, and identifying the actuator mounting interface
  • Proof-of-design test certification for each valve design in accordance with the governing design standard
  • Coating system product data, including the AWWA C550 compliance statement, the dry film thickness, and the NSF/ANSI/CAN 61 listing where the valve is in potable water service
  • Elastomer compound data for the seat, stating the compound, the durometer hardness per ASTM D2240, and the service fluid and temperature range the manufacturer rates it for
  • Valve box and extension stem product data for buried valves, identifying the box type, the adjustment range, the lid marking, and the stem guide arrangement
  • A field test plan identifying the operating test, the leakage observation during the piping pressure test, and the record form
Action Submittals Requiredcheckbox
☑ Valve product data by size, class, body style, and service
☑ Dimensioned valve drawings with disc swing clearance
☑ Manual operator data
☑ Torque data and actuator mounting interface for power-actuated valves
☑ Proof-of-design test certification
☑ Coating system product data
☐ Seat elastomer compound data
☐ Valve box and extension stem product data
☑ Field test plan
3.1.2 Manufacture of a valve shall not begin until the submittal covering that valve has been returned by the Engineer of Record.
3.1.3 Each valve submittal shall be internally consistent across the valve, the operator, the coating, and the mounting interface, and the Contractor shall bear the cost of resubmission caused by internal inconsistency in its own submittal.

3.2 Closeout Submittals

3.2.1 The Contractor shall submit the following at substantial completion, before the butterfly valves are accepted:
  • Certified factory test reports for every valve, identified by serial number, recording the hydrostatic test, the leakage test, and the operational test with their pressures, durations, and results
  • Signed and dated field operating test records for every valve, recording the number of turns to close, the input effort, the position indicator agreement, and the direction of opening
  • The leakage observation record for every valve that bounded a piping pressure test section
  • Record drawings locating every buried valve by tie dimensions to permanent surface features, with the depth to the operating nut, the number of turns to close, and the direction of opening
  • Operation and maintenance data for each valve size and operator type, including seat adjustment and replacement, shaft seal replacement, and operator lubrication
  • Coating inspection records for shop coatings, recording the dry film thickness and the holiday test result for each valve
  • Spare parts receipt signed by the Owner's representative
  • Warranty documentation
Closeout Submittals Requiredcheckbox
☑ Certified factory test reports by serial number
☑ Field operating test records
☑ Leakage observation record during piping pressure tests
☑ Record drawings with buried valve ties, depth, turns, and direction
☑ Operation and maintenance data
☐ Shop coating inspection records
☐ Spare parts receipt
☑ Warranty documentation

4 Quality Assurance

4.1 Manufacturer Qualifications

4.1.1 Butterfly valves shall be the product of a manufacturer that has produced rubber-seated butterfly valves to the selected design standard for not less than five years and has valves of the same design, size, and class in water or wastewater service in North America.
4.1.2 The manufacturer shall furnish, on request, a list of not fewer than five installations of valves of the same design, size range, and class that have been in service for not less than five years.
4.1.3 Where the parties disagree whether a listed installation is of the same design, size range, and class, the Engineer of Record shall make the initial determination.
4.1.4 Replacement seats, shaft seals, bearings, and operator parts shall be available from the manufacturer for not less than fifteen years after shipment.

4.2 Proof of Design

4.2.1 Each valve design furnished shall have passed the proof-of-design tests the governing design standard prescribes for its size and class, and the proof-of-design certification shall be furnished as indicated in the datasheet.
Proof-of-Design Certificationradio
● Certified report of proof-of-design testing previously performed on the same design, size, and class
○ Proof-of-design testing performed on a valve of this contract and witnessed by the Engineer of Record
NOTE AWWA C504 requires each valve design to have been proven once, by tests that cycle the valve under differential pressure and then confirm that it still seals, and it allows a certified report of that earlier testing to stand for every later valve of the same design. Nearly every project accepts the report, because the test destroys nothing and proves the design rather than the unit. Witnessing a fresh test on a contract valve buys direct evidence at the cost of the test, the travel, and the schedule, and it is chosen where a design is new to the Owner or where the size is at the top of the manufacturer's range. (4.2.2)

4.3 Single-Source Responsibility

4.3.1 Butterfly valves of each design standard furnished under this standard shall be the product of a single manufacturer.
4.3.2 Each valve, its manual operator, and the mounting of any power actuator shall be furnished, assembled, adjusted, and tested by the valve manufacturer as a unit.
NOTE A valve shipped bare and fitted with an operator in the field arrives with nobody responsible for the stop settings, the torque match, or the indicator alignment. The valve manufacturer is the only party who knows the seating torque of its own valve, so the operator is mounted and the stops are set where that number is known. (4.3.3)

4.4 Marking

4.4.1 Each valve shall carry the markings the governing design standard requires, cast or on a permanently attached corrosion-resistant nameplate, including the manufacturer, the size, the pressure class, the design standard, the body material, and the year of manufacture.
4.4.2 Valve markings shall conform to MSS SP-25.
4.4.3 The direction of rotation to open shall be marked on the operator housing of every exposed valve and on the operating nut or the nut collar of every buried valve.

5 Service Conditions

5.1 Valve Schedule

5.1.1 The size, pressure class, body style, service fluid, location, duty, and method of operation of each valve shall be as indicated on the valve schedule.
5.1.2 Valves designated for power actuation shall be as indicated on the valve schedule, and their actuators shall be furnished under Valve And Gate ActuatorsValve and Gate ActuatorsResolves to the current adopted revision.sync/valve-and-gate-actuators.
NOTE Size and class are properties of each location on a project, and a standard that asserts either has decided the hydraulics. The valve schedule carries them per tag, and this standard carries what every valve of a given class and body style has in common. (5.1.3)

5.2 Isolation and Throttling Duty

5.2.1 Valves designated for throttling duty on the valve schedule shall be furnished with a seat, a disc, and an operator rated by the manufacturer for continuous partial-open operation at the differential pressure and velocity stated for that valve.
NOTE A rubber-seated butterfly valve throttles by holding its disc in the flow, and at small openings the velocity past the disc edge rises enough to cavitate and to vibrate the disc against its seat. Manufacturers publish the differential pressure at which each size cavitates at a given opening, and a valve designated for throttling is selected against that curve rather than against the class rating, which describes the closed valve. Valves that throttle continuously are also the ones that wear their shaft bearings, which is why the duty is declared per valve. (5.2.2)
5.2.3 Valves in isolation duty shall be operated to the fully open or fully closed position and shall not be left partially open except during a designated throttling operation.

5.3 Exposed and Buried Service

5.3.2 Each valve shall be furnished for exposed or buried service as indicated for its location on the valve schedule.
5.3.3 Operators on valves installed outdoors shall be furnished with a lubricant rated by its manufacturer for continuous service at Site Ambient Temperature MinimumSite Ambient Temperature MinimumParameterEach project supplies its own value.site-ambient-temperature-minimum and at Site Ambient Temperature MaximumSite Ambient Temperature MaximumParameterEach project supplies its own value.site-ambient-temperature-maximum.
5.3.4 Operators on buried valves, and operators on valves in vaults whose floor is below Seasonal High Groundwater ElevationSeasonal High Groundwater ElevationParameterEach project supplies its own value.seasonal-high-groundwater-elevation, shall be sealed for continuous submergence.
NOTE A vault below the water table floods, and an operator that was sealed for rain rather than for immersion fills with water on the first flood and seizes on the second. The groundwater elevation is a project fact, and the seal rating follows it. (5.3.5)

6 Design Standard and Pressure Class

6.1 Governing Design Standard

6.1.1 The design standard to which butterfly valves are manufactured shall be as indicated in the datasheet.
Design Standard for Butterfly Valvesselect
AWWA C504, with AWWA C516 for valves 78 in. and larger
MSS SP-67
API 609 Category A
API 609 Category B
NOTE AWWA C504 is the standard water and wastewater utilities buy against, and it carries the class system, the proof-of-design tests, the field-replaceable seat requirement at 30 in. and larger, and the operator input limits that the rest of this standard relies on. MSS SP-67 describes the resilient-seated wafer and lug valve of industrial and building piping, which is lighter, shorter, and available below 3 in., and it carries a cold-working-pressure rating rather than an AWWA class. API 609 Category A is the concentric resilient-seated industrial valve and Category B is the offset-disc high-performance valve, selected where the service temperature, the pressure, or the fluid is outside what a rubber seat on an iron body serves, as in a chemical feed line or a high-pressure industrial loop. A water or wastewater plant main is a C504 valve on nearly every project, which is why that is the default, and a project whose small or industrial lines need another standard records it here. (6.1.2)
6.1.3 Where AWWA C504 is selected, valves 78 in. and larger shall conform to AWWA C516.
6.1.4 Where MSS SP-67 is selected, valves shall be Type I, rated for tight shutoff, and shall carry a cold-working-pressure rating not less than the pressure indicated for the valve on the valve schedule.
6.1.5 Where API 609 is selected, valves shall be inspected and tested in accordance with API 598.

6.2 Pressure Class

6.2.1 Valves manufactured to AWWA C504 or AWWA C516 shall be of the pressure class indicated in the datasheet.
AWWA C504 Pressure Classselect
Class 25B
Class 75B
Class 150B
Class 250B
Per drawings — the valve schedule (deferred by default)
6.2.2 Each valve shall be rated for the class differential pressure applied across the closed disc in either direction.
NOTE AWWA C504 rates each class for a differential pressure equal to its class number in psi and for a flow velocity: Class 25B and Class 75B valves for 8 ft/s, and Class 150B and Class 250B valves for 16 ft/s. The velocity rating is a shaft and disc strength rating, not a hydraulic recommendation, and a valve that will see a higher velocity in service than its class allows is selected one class up regardless of its pressure. (6.2.3)
6.2.4 Flange drilling on Class 25B, Class 75B, and Class 150B valves shall conform to ASME B16.1 Class 125, and on Class 250B valves to ASME B16.1 Class 250.
6.2.5 Where a valve is installed in a dead-end position, at a blind flange, or where the downstream piping is to be removed while the upstream side remains pressurized, the valve shall be rated for the full class differential pressure with the downstream flange or pipe removed.

7 Body and End Connections

7.1 Body Material

7.1.1 The valve body material shall be as indicated in the datasheet.
Body Materialselect
Ductile iron, ASTM A536
Gray cast iron, ASTM A126 Class B
Stainless steel, ASTM A743 Grade CF8M
Aluminum bronze, ASTM B148
NOTE Ductile iron carries the same pressure rating as gray iron at a lighter section and survives the bolting stress and the impact that crack a gray iron body, which is why it has displaced gray iron in current water and wastewater practice. Gray iron remains a permitted body under AWWA C504 and is still specified where a utility's existing inventory is gray iron and interchangeability matters. A stainless steel body is selected where the fluid attacks coated iron, as in seawater, brine, or a chemical solution, and it removes the coating as a maintenance item at several times the cost. Aluminum bronze resists seawater and erosion and is selected for the same reasons at a comparable premium. (7.1.2)
7.1.3 Bodies shall be of one-piece construction with integral flanges or ends, except that two-piece bodies designed for mechanical seat retention are permitted on valves 30 in. and larger.
7.1.4 The body shall be designed so that the disc, the seat, the shaft seals, and the bearings can be serviced without removing the body from the line.

7.2 End Connections for Exposed Service

7.2.1 The end connection for valves in exposed service shall be as indicated in the datasheet.
End Connection, Exposed Serviceselect
Flanged, short body
Flanged, long body
Wafer
Lug
Grooved end
NOTE A flanged short-body valve bolts independently to each flange, holds pressure with either side removed, and is the body AWWA C504 lays out first; it is what most plant piping uses, which is why it is the default. A long body adds laying length where a valve must match an existing gate valve's face-to-face or where the disc swing needs room that a reducer would otherwise take. A wafer body is clamped between two flanges by through-bolts and is the lightest and cheapest, and it cannot hold pressure once either flange is unbolted. A lug body bolts to each flange by tapped lugs, so it serves a dead end the way a flanged valve does at closer to a wafer's weight, provided the lugs are rated for the dead-end load. A grooved end valve joins to grooved piping under AWWA C606 without flanges and is chosen where the piping system is grooved throughout. (7.2.2)
7.2.3 Flanged valves shall have laying lengths conforming to the governing design standard for the body style selected, and to ASME B16.10 for valves manufactured to MSS SP-67 or API 609.
7.2.4 Lug-body valves shall be rated by the manufacturer for dead-end service at the full class differential pressure with the downstream flange removed.
7.2.5 Wafer-body valves shall be installed only between two flanges that remain permanently bolted, and shall not be installed at a dead end, at a blind flange, or at an equipment connection that is removed for service.
7.2.6 Grooved-end valves shall have ends conforming to AWWA C606 and shall be rated for the class pressure with the coupling the piping standard furnishes.

7.3 End Connections for Buried Service

7.3.1 The end connection for valves in buried service shall be as indicated in the datasheet.
End Connection, Buried Serviceselect
Mechanical joint
Flanged, short body
Restrained mechanical joint
NOTE A mechanical joint end takes the gasket and gland of AWWA C111/A21.11, tolerates the deflection a trench imposes, and is assembled without the face alignment a flange needs, which is why it is the buried valve end on nearly every water main. A flanged buried valve is used at a vault wall, at a tee that is itself flanged, or where the utility's standard is to flange every buried valve and wrap it. A restrained mechanical joint is selected where the valve is a thrust point and the piping standard restrains the joints rather than blocking them. (7.3.2)
7.3.3 Mechanical-joint ends shall conform to AWWA C111/A21.11, and the glands, gaskets, and bolts shall be furnished with the valve.
7.3.4 Thrust restraint at a buried valve, whether by restrained joint or by thrust block, shall be provided under the standard governing the buried piping.

8 Disc, Seat, and Seating Surfaces

8.1 Disc Material

8.1.1 The disc material shall be as indicated in the datasheet.
Disc Materialselect
Ductile iron, ASTM A536
Gray cast iron, ASTM A126 Class B
Stainless steel, ASTM A743 Grade CF8M
Aluminum bronze, ASTM B148
NOTE The disc carries the full class differential pressure as a plate loaded across its shaft, so its material is a strength selection first. Ductile iron carries that load at the section a stainless or bronze seating edge is applied to and is the disc on most valves. Gray iron carries it at a heavier section and is the lower-cost disc where the utility's inventory is gray iron. A stainless steel disc is selected where the coating on an iron disc would be the first thing the fluid attacked, as in seawater, brine, or a chemical solution, and an aluminum bronze disc for the same services where erosion is also present. (8.1.2)
8.1.3 Discs shall rotate through 90° from the fully open to the fully closed position and shall be free of external ribs or stiffeners that cross the flow path.
8.1.4 The disc shall be secured to the shaft with corrosion-resistant pins, keys, or a taper fit so that the connection carries the full operator torque and the full dynamic torque without loosening.
8.1.5 Disc-to-shaft pins shall be of the same material as the shaft or of a material the manufacturer rates as galvanically compatible with the shaft and the disc in the service fluid.

8.2 Seat Location and Retention

8.2.1 The seat shall be located as indicated in the datasheet.
Seat Locationradio
○ Seat on the body, mating a metal seating edge on the disc
○ Seat on the disc, mating a metal seating surface in the body
8.2.2 The seat shall be retained as indicated in the datasheet.
Seat Retentionradio
○ Bonded or vulcanized to the body or disc
○ Mechanically retained, adjustable and replaceable in the field
NOTE A seat on the body leaves the disc as a plain plate with a metal edge, so the disc is light, the seat is a ring that is replaced from the body side, and the full body bore is rubber-lined where the seat sits. A seat on the disc puts the rubber on the moving part and leaves the body with a metal seating ring, so the body coating is not interrupted and the seat is replaced with the disc. Neither is the norm across manufacturers, and a utility that standardizes on one does so to match its stock of spares. A bonded or vulcanized seat has no retaining hardware to loosen, so it is the simpler seat and the one with no field adjustment. A mechanically retained seat is adjusted and replaced in the line, which is why AWWA C504 requires it at 30 in. and larger, where removing a valve to reseat it means a crane and an outage. (8.2.3)
8.2.4 On valves 30 in. and larger, the seat shall be mechanically retained, adjustable around its full circumference, and replaceable in the field without removing the valve from the line and without removing the operator, the disc, or the shaft.
8.2.5 Seat-retaining hardware shall be of the same stainless steel as the shaft or of a stainless steel the manufacturer rates as galvanically compatible with it.
8.2.6 Bonded and vulcanized seats shall have an adhesion to the base metal not less than the value the governing design standard requires when tested in accordance with ASTM D429.
8.2.7 Seats shall be designed so that the seating edge contacts the seat over the full 360° of the circumference at the closed position and so that the disc does not touch the seat at any intermediate position of travel.

8.3 Seat Elastomer

8.3.1 The seat elastomer shall be as indicated in the datasheet.
Seat Elastomerselect
EPDM
Nitrile (Buna-N)
Natural rubber
Neoprene
Fluoroelastomer
NOTE The seat is the only part of the valve that seals, so its compound is matched to the fluid first. EPDM resists chlorine and chloramine, ozone, and the hot water of a wash cycle, and it is attacked by petroleum oils and greases, which makes it the usual seat in treated and potable water and a poor one in raw wastewater that carries grease. Nitrile resists oils, grease, and hydrocarbons and swells in chloraminated water over time, which makes it the usual seat in wastewater, sludge, and raw water and a poor one downstream of chloramination. Natural rubber has the best abrasion resistance of the group and is selected for grit-laden water at the cost of ozone and oil resistance. Neoprene sits between EPDM and nitrile on oil resistance and is specified where a utility's stock is neoprene. Fluoroelastomer resists chemicals that attack all four and is selected for chemical feed and industrial service at several times the cost. No compound is the norm across the water and wastewater services this standard covers, so none is defaulted. (8.3.2)
8.3.3 The seat compound shall be rated by its manufacturer for the service fluid and the service temperature range indicated for the valve on the valve schedule.
8.3.4 Seats in potable water service shall be of a compound certified to NSF/ANSI/CAN 61.
8.3.5 Seat hardness shall be within the range the valve manufacturer publishes for the compound when tested in accordance with ASTM D2240, and the durometer value shall be stated on the elastomer compound data submitted.

8.4 Metal Seating Surface

8.4.1 The metal seating edge or seating ring that mates with the rubber seat shall be of the material indicated in the datasheet.
Metal Seating Surface Materialselect
Type 316 stainless steel
Type 304 stainless steel
Nickel-copper alloy
NOTE The metal seating surface is the one surface the rubber seat is compressed against on every closure, so it has to stay smooth and free of corrosion product for the life of the seat. Type 316 stainless steel resists chloride pitting in wastewater and in chloraminated water and is what most water and wastewater specifications call for. Type 304 resists the same services where chlorides are low, at a modest saving. A nickel-copper alloy resists seawater and brine where both stainless grades pit, at a premium. (8.4.2)
8.4.3 The metal seating surface shall be secured to the disc or body by a method the manufacturer rates for the class differential pressure, and shall be machined and polished to a finish that seals against the rubber seat without cutting it.
8.4.4 Where the seating surface is a separate ring, it shall be of a single piece or of segments joined so that no seam is exposed to the seat at the closed position.

9 Shaft, Bearings, and Shaft Seals

9.1 Shaft Material and Configuration

9.1.1 The shaft material shall be as indicated in the datasheet.
Shaft Materialselect
Type 304 stainless steel, ASTM A276
Type 316 stainless steel, ASTM A276
Type 17-4 PH stainless steel, ASTM A564
Nickel-copper alloy
NOTE The shaft carries the full operator torque into the disc and the full dynamic torque out of it, and in a wet bearing it is the part that corrodes where it is loaded. Type 304 is the AWWA C504 baseline and serves treated water where chlorides are low. Type 316 resists chloride pitting at the bearing and is specified across wastewater and chloraminated water at a small premium. Type 17-4 PH has roughly twice the yield strength of the austenitic grades and is selected where the class and the size push the shaft diameter past what the body can house, as on a large Class 250B valve, and it is less corrosion resistant than Type 316. A nickel-copper alloy resists seawater and brine where every stainless grade pits. No grade is the norm across the sizes and services this standard covers. (9.1.2)
9.1.3 The shaft configuration shall be as indicated in the datasheet.
Shaft Configurationradio
○ One-piece shaft through the disc
○ Two-piece stub shafts
Manufacturer's standard (by default)
NOTE A one-piece shaft passes through the disc and carries torque with no joint in the shaft itself, and it is what small and medium sizes are built with. Two-piece stub shafts enter the disc from each side and leave the disc hub open to the flow between them, so a large disc is lighter and its flow area larger, and the two stubs must each be pinned to the disc. Each manufacturer builds each size one way, and the choice follows the design rather than the project. (9.1.4)
9.1.5 Shaft diameter shall be not less than the diameter the governing design standard requires for the size and class of the valve.
9.1.6 Shafts shall turn in bearings and shall not bear directly on the body or the disc.

9.2 Bearings and Thrust Bearing

9.2.1 Shaft bearings shall be of the material indicated in the datasheet.
Shaft Bearing Materialselect
Self-lubricating bronze
PTFE-lined stainless steel or bronze
Nylon or acetal polymer
Manufacturer's standard (by default)
9.2.2 Shaft bearings shall be of the sleeve type, self-lubricating, and corrosion resistant in the service fluid, and shall not require lubrication from outside the valve.
NOTE A bronze sleeve bearing wears slowly and tolerates grit, and it is galvanically active against a stainless shaft in brackish water. A PTFE-lined bearing has the lowest friction, which reduces the operator torque at the seat, and its liner is cut by grit that a bronze bearing tolerates. A polymer bearing is corrosion-free and inexpensive and has the lowest load rating, so it serves small sizes and low classes. Each manufacturer builds each size and class around one of them, and the choice follows that design. (9.2.3)
9.2.4 Bearing loads at the class differential pressure shall not exceed the limit the governing design standard sets for the bearing and shaft materials.
9.2.5 Each valve shall be furnished with a two-way thrust bearing that holds the disc centered in the seat throughout the pressure range, without external adjustment.

9.3 Shaft Seals

9.3.1 Shaft seals shall be of the type indicated in the datasheet.
Shaft Seal Typeselect
Self-adjusting split V-type packing
O-ring seals
Pull-down packing
Manufacturer's standard (by default)
NOTE Self-adjusting V packing takes up its own wear under a spring and needs no attention until it is replaced, and it holds the shaft friction a little higher than O-rings. O-ring seals have the lowest friction and are replaced as a set, and they depend on a smooth shaft finish that grit in the bearing area can scratch. Pull-down packing is adjusted by hand with a gland and is the oldest of the three, chosen by utilities whose crews adjust packing on every valve they own. All three are permitted by AWWA C504, and each manufacturer offers one or two as its design. (9.3.2)
9.3.3 Shaft seals shall be replaceable without removing the valve from the line, without removing the disc or the shaft, and without removing the operator.
9.3.4 Where a shaft seal is below the operator and is not accessible with the operator mounted, the valve shall be furnished with an extension between the body and the operator that exposes the seal.

10 Manual Operators

10.1 Operator Type for Exposed Service

10.1.1 Manual operators on valves in exposed service shall be of the type indicated in the datasheet.
Manual Operator, Exposed Serviceselect
Worm-gear operator with handwheel
Traveling-nut operator with handwheel
Worm-gear operator with chainwheel
Worm-gear operator with 2 in. square operating nut
Notched-plate lever handle
10.1.3 Manual operators on valves manufactured to AWWA C504 or AWWA C516 shall be of the worm-gear or traveling-nut type, totally enclosed, self-locking, and capable of holding the disc at any position between fully open and fully closed without creep under the class differential pressure and velocity.
10.1.4 Notched-plate lever handles shall be furnished only on valves manufactured to MSS SP-67 or API 609 in sizes 6 in. and smaller.
10.1.5 Manual operators on exposed valves shall be furnished with a position indicator that shows the disc position continuously from fully open to fully closed and that is visible from the operating position.
10.1.6 Manual operators shall be furnished with adjustable mechanical stops at the fully open and fully closed positions that carry the full operator output without transmitting it to the disc or the seat.
10.1.7 Chainwheel operators shall have the chain looped to within 3 ft of the operating floor and guided so that it cannot leave the wheel.
10.1.8 Gearing in manual operators shall run in grease in a housing sealed against the entry of water and dust, and the housing on an exposed valve shall be furnished with a grease fitting or a filled-for-life designation on the nameplate.

10.2 Operator Type for Buried Service

10.2.1 Manual operators on valves in buried service shall be of the type indicated in the datasheet.
Buried-Service Operator Typeradio
○ Worm-gear operator
○ Traveling-nut operator
Manufacturer's standard (by default)
NOTE Both operator types are permitted for buried service under AWWA C504, and a buried operator is never seen again after backfill, so the type matters less than the sealing. Each manufacturer builds its buried operator one way for each size range. (10.2.2)
10.2.3 Buried-service operators shall be totally enclosed, packed with grease, and sealed with O-rings or an equivalent seal at every shaft and cover for continuous submergence.
10.2.4 Buried-service operators shall terminate in a 2 in. square operating nut conforming to the dimensions of AWWA C504, with the direction of opening cast or stamped on the nut or on a collar at its base.
10.2.5 Buried-service operators shall be furnished with a stem guide or a stuffing box at the operating nut that keeps soil from entering the operator through the nut shaft.

10.3 Direction of Rotation

10.3.1 Valves shall open in the direction of rotation indicated in the datasheet.
Direction of Rotation to Openradio
● Counterclockwise (open left)
○ Clockwise (open right)
NOTE Most North American utilities open their valves counterclockwise, and a plant whose valves open the other way from the distribution system around it has an operator closing a valve that was meant to be opened on the day it matters. A minority of utilities, often whole regions, open clockwise, and a project in their territory follows the owning utility's practice without exception. The direction is set once for a project and is cast on every operator. (10.3.2)
10.3.3 Every valve on the project shall open in the same direction of rotation, and the direction shall match the practice of the utility that will operate the valves.

10.4 Operator Sizing

10.4.1 Each manual operator shall be sized to seat, unseat, and hold the disc at the class differential pressure and the class flow velocity with an input effort not exceeding the limits the governing design standard sets for a handwheel, a chainwheel, and an operating nut.
10.4.2 Operators for valves designated for throttling duty on the valve schedule shall additionally be sized for the dynamic torque at the throttling condition stated for that valve.
10.4.3 The valve manufacturer shall publish, for each valve size and class, the number of turns of the handwheel or nut from fully open to fully closed, and that number shall be stated on the operator data submitted.
NOTE Operators sized to the class rating rather than to the project's operating pressure are what let a valve be closed on the day the pressure is at its highest, which is the day a main breaks and the pressure on the closed disc is the full static head of the system. An operator sized to the normal operating pressure is sized to the one condition under which nobody needs to close the valve. (10.4.4)
10.4.5 An operator that cannot seat or unseat the valve at the class differential pressure within the published input effort shall be replaced by the Contractor with an operator that can, at the Contractor's cost.

11 Power Actuation Interface

NOTE Electric actuators under AWWA C542 and pneumatic and hydraulic cylinder actuators under AWWA C541 on butterfly valves, and the valve's open, closed, and position signals to the supervisory system, are furnished under Valve And Gate ActuatorsValve and Gate ActuatorsResolves to the current adopted revision.sync/valve-and-gate-actuators; the actuator and positioner of a butterfly valve in a modulating control loop are furnished under Control Valves And ActuatorsControl Valves and ActuatorsResolves to the current adopted revision.sync/control-valves-and-actuators. This standard furnishes the valve, the mounting interface, and the torque data. (11.1)
11.2 For each valve designated for power actuation, the valve manufacturer shall furnish the seating torque, the unseating torque, the dynamic torque at the class differential pressure and velocity, the dynamic torque at any throttling condition stated on the valve schedule, and the maximum torque the shaft and the disc connection withstand.
11.3 The torque data furnished shall be the basis on which the actuator is sized under Valve And Gate ActuatorsValve and Gate ActuatorsResolves to the current adopted revision.sync/valve-and-gate-actuators, and the valve manufacturer shall confirm in writing that the selected actuator's rated output does not exceed the maximum shaft torque of the valve.
11.4 The actuator mounting flange and the drive connection on the valve shall conform to ISO 5211 or MSS SP-101, or shall be of the valve manufacturer's design where the valve size exceeds the range of those standards.
11.5 Each power actuator shall be mounted on its valve by the valve manufacturer, with the open and closed stops set and the assembly cycled through full travel before shipment.
11.6 Valves designated for power actuation shall be furnished with a manual override on the actuator or with a declutchable manual operator, so that the valve can be operated with the actuator de-energized.
NOTE The maximum shaft torque is the number that protects the valve from its own actuator. An electric actuator sized with a generous margin and a torque switch set at the top of its range can twist a stub shaft out of a disc on the first stall, and the valve manufacturer is the only party who knows where that limit is. (11.7)

12 Coatings and Linings

12.1 Shop Coating System

12.1.1 Ferrous interior and exterior surfaces of each valve body and disc, except seating surfaces, bearing surfaces, and machined flange faces, shall be coated at the factory in accordance with AWWA C550 with the system indicated in the datasheet.
Shop Coating System on Ferrous Surfacesselect
Fusion-bonded epoxy, AWWA C550
Two-part liquid epoxy, AWWA C550
Not applicable, corrosion-resistant alloy body and disc
Manufacturer's standard (by default)
NOTE Fusion-bonded epoxy is applied as a powder to a heated casting and cures into a hard, holiday-free film that bonds to blast-cleaned iron better than any liquid coating, and it is applied only in a shop equipped to heat the casting. Two-part liquid epoxy to the same standard is applied by spray in any coating shop and is the system a manufacturer uses where its castings are too large to heat. Both meet AWWA C550, both are certified to NSF/ANSI/CAN 61 by the manufacturers that offer them, and the choice follows the manufacturer's process rather than the project. A stainless steel or aluminum bronze body and disc are not coated. (12.1.2)
12.1.3 Shop coatings on valves in potable water service shall be certified to NSF/ANSI/CAN 61.
12.1.4 Shop coatings shall be applied over a surface prepared and to a dry film thickness in accordance with AWWA C550, and shall be holiday tested in accordance with that standard before shipment.
12.1.5 Coating that is damaged in shipment or installation shall be repaired with the coating manufacturer's repair material in accordance with the coating manufacturer's written procedure, and a repair that cannot restore a holiday-free film shall be cause for rejection of the valve.
12.1.6 Stainless steel, aluminum bronze, and nickel-copper surfaces shall not be coated.

12.2 Exterior Finish on Exposed Valves

12.2.1 The exterior finish on valves in exposed service shall be as indicated in the datasheet.
Exterior Finish, Exposed Valvesradio
○ Shop epoxy as the finished coating
○ Shop epoxy as the primer for a field-applied finish coat
12.2.3 Where the datasheet selects a field-applied finish coat, the shop epoxy shall be compatible with the finish coat system furnished under High Performance CoatingsHigh-Performance CoatingsResolves to the current adopted revision.sync/high-performance-coatings, and the valve manufacturer shall state the surface preparation the finish coat requires over its epoxy.
12.2.4 Where the datasheet selects a field-applied finish coat, the operator housing and handwheel shall be finished in the field under High Performance CoatingsHigh-Performance CoatingsResolves to the current adopted revision.sync/high-performance-coatings in the color the finish scheme assigns to valve operators.

13 Buried Service Provisions

13.1 Valve Boxes

13.1.1 Each buried valve shall be furnished with a valve box of the type indicated in the datasheet, extending from the valve to finished grade, except where the valve is installed on a site distribution main whose valve box is furnished under Water Distribution PipingSite Water Distribution PipingResolves to the current adopted revision.sync/water-distribution-piping.
Valve Box Typeselect
Cast-iron two-piece slide-type box
Cast-iron three-piece screw-type box
Precast concrete valve vault with access cover
NOTE A two-piece slide box telescopes to grade and is set without threading, so it adjusts in the trench and again at final grading, and it carries no load to the valve if the lower section sits on a base plate clear of the operator. A three-piece screw box is adjusted by turning the upper section and holds its setting against traffic and frost better than a slide box, and it is the box of utilities that have standardized on it. A precast vault gives a crew room to reach the operator, the shaft seals, and a power actuator, and it is used on large valves, on valves that are operated often, and wherever a valve is to be actuated electrically. (13.1.2)
13.1.3 Valve boxes shall be cast iron, of a two-piece or three-piece adjustable design, with a base section that bears on the soil or on a base plate and not on the valve body or operator, and with a lid marked for the service.
13.1.4 The valve box shall be set plumb and centered over the operating nut, and the upper section shall be adjusted to finished grade after final grading.
13.1.5 The valve box lid shall be marked "WATER" for potable and raw water, "SEWER" for wastewater and sludge, and "RECLAIMED" for reclaimed water, in letters cast into the lid.
NOTE A valve box that bears on the valve transfers the weight of every vehicle that drives over the lid into the operator housing, and the housing cracks or the operator binds in the first winter. The base section sits on the soil, on a base plate, or on a concrete collar poured around the operator, never on the valve. (13.1.6)

13.2 Extension Stems

13.2.1 Where the operating nut of a buried valve would otherwise be deeper below finished grade than the depth indicated in the datasheet, an extension stem shall be furnished that brings the operating nut to within that depth of grade.
Operating Nut Depth Below Finished Graderange
in.
12182436486072
NOTE An operating key reaches a nut a few feet down without trouble and loses its purchase as the depth grows, and a crew that cannot find or seat the key on a deep nut leaves the valve as it found it. Utilities set the depth their crews work to, commonly within a few feet of grade, and a deeper main gets an extension stem that brings the nut up. The depth is the utility's practice rather than the valve's, which is why it is not defaulted. (13.2.2)
13.2.3 Extension stems shall be of steel or stainless steel, sized to carry the full operator input torque, fitted with a 2 in. square operating nut at the top and a socket that engages the valve nut at the bottom, and held centered in the valve box by a stem guide.
13.2.4 Extension stems shall be pinned or bolted to the valve operating nut so that the stem cannot lift off the nut when the key is withdrawn.
NOTE Floor stands and the extension stems that operate exposed valves from a floor above are furnished under Valve And Gate ActuatorsValve and Gate ActuatorsResolves to the current adopted revision.sync/valve-and-gate-actuators; this article covers extension stems inside valve boxes on buried valves only. (13.2.5)

14 Factory Testing

14.1 Production Tests

14.1.1 Each valve shall be hydrostatically shell tested at the factory in accordance with the governing design standard, at the pressure and for the duration that standard prescribes for its class, with no leakage through the body, the shaft seals, or the body joints.
14.1.2 Each valve shall be leakage tested at the factory with the disc closed and the class differential pressure applied to each side of the disc in turn, for the duration the governing design standard prescribes, with no leakage past the seat.
14.1.3 Each valve shall be operationally tested at the factory by cycling it through full travel with its manual operator or its mounted actuator, and the stops, the position indicator, and the direction of opening shall be verified during that cycle.
14.1.4 Valves manufactured to API 609 shall be inspected and tested in accordance with API 598, and the shell test and the seat test of API 598 shall satisfy the production tests of this article.
NOTE The leakage test is performed in each direction because an isolation valve is closed from whichever side the pressure happens to be on, and a seat that seals against flow from one side does not necessarily seal against flow from the other. A valve that passes in one direction and fails in the other has a seat that is misaligned or a disc that is off center, both of which the thrust bearing is supposed to prevent. (14.1.5)
14.1.6 A valve that fails any factory test shall be corrected and retested, and the Contractor shall bear the cost of the correction and the retest.
14.1.7 Certified test reports identifying each valve by serial number shall be furnished for every valve before shipment, and no valve shall be shipped without one.

14.2 Test Witnessing

14.2.1 Factory tests shall be witnessed as indicated in the datasheet.
Factory Test Witnessingselect
Certified test reports accepted, no witnessing
Witnessed by the Engineer of Record for every valve
Witnessed by the Engineer of Record for designated valves
14.2.2 Where witnessing of designated valves is selected, the valves to be witnessed shall be as indicated on the valve schedule.
NOTE A certified report from a manufacturer that tests every valve as a matter of course is what nearly every project accepts, and the cost of witnessing every valve is a trip to the factory for each shipment. Witnessing is bought for the valves whose failure would drain a plant, which on most projects are the few largest, and the valve schedule designates them. Witnessing every valve is chosen where the Owner has had a shipment fail in the field or where the manufacturer is new to the Owner. (14.2.3)
14.2.4 Where witnessing is selected, the Contractor shall give the Engineer of Record not less than ten business days notice of the test date.
14.2.5 Where witnessing is selected, the Contractor shall bear the cost of the Engineer of Record's attendance at a retest that follows a failed test.

15 Delivery, Storage, and Handling

15.1 Valves shall be shipped with the disc in the position the manufacturer designates for shipment and storage, with the end openings covered to keep debris off the seat and the seating surface, and with the covers left in place until the valve is set in the line.
15.2 Valves shall be lifted by the body, by lifting lugs the manufacturer provides, or by slings around the body, and shall not be lifted by the operator, the actuator, the handwheel, the shaft, or the disc.
15.3 Valves shall be stored off the ground on timbers or pallets, under cover, with the operator or actuator protected from weather, and valves with rubber seats shall be stored out of direct sunlight.
NOTE Rubber takes a set where it is compressed and left, and it degrades under ultraviolet light; a valve stored closed in the sun for a construction season arrives at the line with a seat that has already lost the resilience it seals with. The manufacturer's shipping position relieves the seat, and the cover keeps the sun off it. (15.4)
15.5 Each valve shall be delivered with its certified test reports, its mechanical-joint accessories where furnished, its operating nut or handwheel, and its extension stem and valve box where furnished, and the Contractor shall verify the delivery against the approved submittal before the valve is moved to the trench or the piping.
15.6 The Contractor shall bear the cost of repairing or replacing a valve damaged in delivery, storage, or handling.

16 Installation

16.1 Exposed Valves

16.1.1 Before a valve is set, the Contractor shall verify that the inside diameter of the pipe, fitting, lining, or reducer on each side of the valve clears the disc through its full swing, and where it does not, the Contractor shall install a spool or a spacer between the valve and the obstruction.
NOTE The disc of a butterfly valve swings past the body faces when it opens, and a pipe or a fitting whose bore is smaller than the valve's nominal size stops it before it is fully open. Lined pipe, pipe of a heavier wall, a reducer bolted directly to the valve, and a check valve or a flap valve flanged to it are the common obstructions, and a disc that strikes one on the first opening is damaged on the edge that seals. (16.1.2)
16.1.3 Flanged valves shall be installed with the mating flanges aligned, parallel, and concentric before the bolts are tightened, and the valve shall not be used to draw misaligned piping together.
16.1.4 Wafer and lug valves shall be centered between the mating flanges with the disc in the position the manufacturer designates for installation, and the flange bolts shall be tightened evenly in a crossing pattern in not fewer than three passes.
16.1.5 The shaft of each valve in horizontal piping shall be oriented as indicated in the datasheet.
Shaft Orientation in Horizontal Pipingradio
○ Horizontal
○ Vertical
16.1.7 Valves shall be supported independently of the piping so that no piping load, thrust, or vibration is carried into the valve body, and the supports shall be furnished under the standard governing the piping.
16.1.8 Each exposed valve shall be installed with clearance for the operator, the handwheel, the actuator, and the removal of the shaft seals and the seat, and the clearance shall be not less than the manufacturer's published service clearance.
16.1.9 Flange bolting and gaskets at each valve shall be furnished and installed under the standard governing the piping, and shall be rated for the class pressure of the valve.
16.1.10 Where a valve is installed against a flat-faced cast iron or ductile iron flange, a full-face gasket shall be used and a raised-face mating flange shall not be used.
16.1.11 Each valve shall be cycled through full travel after the flanges are tightened and before the piping is tested, and a valve whose disc contacts the piping, the lining, or the gasket at any position shall be removed and reinstalled with the obstruction corrected.

16.2 Buried Valves

16.2.1 Buried valves shall be set on compacted bedding of the same material and to the same depth as the bedding of the adjacent pipe, with the operating nut vertical and centered under the valve box.
16.2.2 Each buried valve shall be operated through its valve box with an operating key, from fully open to fully closed and back, before backfill is placed above the valve and again after backfill is complete.
16.2.3 Backfill around a buried valve shall be placed and compacted under the standard governing the buried piping, and the valve box shall be held plumb and centered on the operating nut throughout backfill.
16.2.4 Where the valve box lid is in a pavement, the box shall be set so that the lid is flush with the finished pavement, and where it is in a landscaped area, the lid shall be set flush with the finished grade or raised as the Owner's standard requires.
16.2.5 Buried valves shall be located on the record drawings by not fewer than two tie dimensions to permanent surface features, with the depth from the lid to the operating nut and the number of turns to close.
NOTE A buried valve that cannot be found is a valve that does not exist on the day the main breaks. Two ties to features that will still be there in twenty years, and a depth and a turn count that tell the crew what they are reaching for, are what make the valve usable by someone who did not install it. (16.2.6)
16.2.7 Where a buried valve is on a site distribution main, the valve box, its setting, and the record ties shall be as required under Water Distribution PipingSite Water Distribution PipingResolves to the current adopted revision.sync/water-distribution-piping, and this article shall apply to the valve itself.

16.3 Field Testing

16.3.1 Each valve shall be operated through full travel after installation, and the Contractor shall record the number of turns to close, the input effort at the handwheel or nut, the agreement of the position indicator with the actual disc position, and the direction of opening.
16.3.2 A valve whose input effort at the handwheel or nut exceeds the limit the governing design standard sets, or whose position indicator does not agree with the disc, shall be corrected by the Contractor before the piping is tested.
16.3.3 Each valve that bounds a section of piping under hydrostatic test shall be observed for leakage past the closed disc during the test, and a valve that leaks past its seat at the test pressure of the piping shall be removed, repaired or replaced, and retested.
16.3.4 The field test shall be witnessed by the party indicated in the datasheet.
Field Test Witnessselect
Engineer of Record or the Engineer's representative
Owner's operations representative
Contractor's quality control representative
NOTE The Engineer of Record witnesses the test on most projects because the test record is the Engineer's evidence that the valve matches its submittal. An Owner's operator witnesses where the plant staff will operate the valves and wants to see each one work before it is handed over, which is common on a plant expansion. A contractor's quality control representative witnesses where the contract carries a quality control program and the Engineer reviews its records rather than attending. (16.3.5)
16.3.6 The Contractor shall give the witnessing party not less than five business days notice of a scheduled field test.
16.3.7 The Contractor shall bear the cost of correcting a valve that fails a field test and of the retest, including the cost of the witness's attendance at the retest.
16.3.8 The piping pressure test itself shall be performed under the standard governing the piping, and a butterfly valve shall not be used to isolate a test section at a test pressure exceeding the class differential pressure of the valve.

17 Warranty

17.1 The Contractor shall warrant each butterfly valve, its operator, and the mounting of any power actuator against defects in materials and workmanship for the period indicated in the datasheet, measured from the date of substantial completion.
Valve Warranty Periodrange
years
1235
Default: Not less than 1 years
17.2 Where the contract General Conditions specify a longer warranty period than the datasheet, the longer period shall govern.
17.3 A valve that leaks past its seat at or below the class differential pressure, leaks through its shaft seals or body, or cannot be operated within the input effort limits of the governing design standard within the warranty period shall be repaired or replaced by the Contractor at no cost to the Owner.
17.4 The Contractor shall bear the cost of excavating and backfilling to reach a buried valve for a warranted repair, of draining and refilling the piping the repair requires, and of repairing any other work damaged by the failure or by the repair.
17.5 A repaired or replaced valve shall carry a warranty running for a full new term from the date the repair is accepted, or for the remainder of the original term, whichever ends later.
NOTE The cost that goes unassigned in a valve warranty is never the valve. It is the excavation to reach a buried one, the outage to drain the main it sits in, and the disinfection of a potable main that was opened. Naming those costs is what makes the warranty worth having on a valve that cost less than the trench around it. (17.6)

18 Spare Parts

18.1 The Contractor shall furnish the spare parts indicated in the datasheet, packaged, labeled with the valve size and class they fit, and delivered to the Owner before substantial completion.
Spare Parts Furnishedcheckbox
☑ One shaft seal set for each valve size and shaft seal type
☐ One replacement seat for each size of valve 30 in. and larger with a field-replaceable seat
☐ One operator repair kit for each manual operator size
☑ Two operating keys for the 2 in. square nut, sized for the deepest valve on the project
☐ One set of seat-retaining hardware for each size with a mechanically retained seat
18.2 Spare parts shall be the products of the valve manufacturer and shall be interchangeable with the parts installed in the valves furnished.
NOTE A shaft seal is the one wearing part every butterfly valve has and the one a crew replaces in place, so a set per size is the spare that is used. A replacement seat for a large valve is a long-lead casting-matched part that is worth holding where the valve isolates something the plant cannot do without. Operating keys are furnished because a buried valve without a key within reach is a valve nobody can close. (18.3)
18.4 The spare parts list, with the manufacturer's part numbers, shall be included in the operation and maintenance data.

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