Slide Gates and Stop Logs
Initial publication
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to Rev 1
in Slide Gates and Stop Logs.
+---
+title: Slide Gates and Stop Logs
+category: Process / Gates
+description: >
+ When to use: Slide gates, weir gates, flap gates, and stop logs on the walls and in the channels of water, wastewater, reclaimed water, and industrial process structures, including fabricated stainless steel slide gates under AWWA C561, fabricated aluminum under AWWA C562, fabricated composite under AWWA C563, cast iron under AWWA C560, open-channel fabricated-metal slide and weir gates under AWWA C513, cast iron and fabricated flap gates at outfalls and backflow points, and aluminum, fiberglass, and stainless steel stop logs with their guides, lifting devices, and storage racks. Covers the gate schedule interface, the seating and unseating design heads and the leakage allowance, the frame, slide, guides, seats, and seals, the invert configuration, the stem, stem guides, stem cover, and the manual lift on a self-contained gate, the thrust and the mounting interface a power actuator or floor stand is furnished to, the wall thimble, the anchor bolts, the tolerance the concrete must meet, finishes, shop assembly and tests, installation, and the field leakage and operation tests.
+ Not intended for: Electric, pneumatic, and hydraulic actuators, floor stands and bench stands bought separately from the gate, and the extension stems that reach them (see [[sync/valve-and-gate-actuators]]); a gate that modulates against a process variable in a control loop, with the positioner that duty requires (see [[sync/control-valves-and-actuators]]); the liquid-retaining structure itself, its blockouts, the casting-in of the items this standard furnishes for it, and their grouting once set (see [[sync/water-retaining-concrete-structures]], [[sync/cast-in-place-concrete]], and [[sync/concrete-accessories]]); post-installed anchors (see [[sync/post-installed-anchors]]) and non-shrink grout (see [[sync/non-shrink-grout]]); the outfall headwall a flap gate mounts on (see [[sync/site-concrete-structures]]) and the storm sewer behind it (see [[sync/storm-drainage]]); site and perimeter slide gates under ASTM F1184 (see [[sync/fencing-and-gates]]); duct and damper slide gates (see [[sync/louvers-and-dampers]] and [[sync/dust-and-fume-collection]]); butterfly and eccentric plug valves (see [[sync/butterfly-valves]] and [[sync/eccentric-plug-valves]]); the process piping and wall pipes a flap gate or a thimble connects to (see [[sync/ductile-iron-process-piping]] and [[sync/steel-and-stainless-process-piping]]); field-applied finish coatings (see [[sync/high-performance-coatings]]); gate tags (see [[sync/mechanical-identification]]); and radial, roller, and bulkhead gates for dams and intake structures, elastomer duckbill check valves, screening and grit equipment, and clarifier mechanisms, which are not yet owned by a SynC standard.
+---
+
+# Scope {toc}
+
+## This standard covers the gates that control flow through the walls and channels of a process structure: the slide gate that closes an opening by lifting a slide in a frame, the weir gate that opens by lowering its slide so water passes over the top, the flap gate that swings shut against backflow, and the stop logs that are dropped into guides to isolate a channel while the gate it serves is repaired. {note}
+
+## The boundary of the work is each gate as a shop-assembled unit: the frame, the slide, the guides, the seats and seals, the stem and its guides and cover, the manual lift on a self-contained gate, the wall thimble or the anchor bolts that fix the frame to the structure, the stop log sections with their guides, lifting devices, and storage rack, the shop assembly and tests that prove the unit before it ships, and the installation and field tests that prove it in the structure. {note}
+
+## This standard is read with [[sync/common-work-results-process]], which carries once for every item of process equipment the equipment numbering and nameplates, the submittal procedures and the process equipment data sheet, the manufacturer experience and reference terms, the enclosure types of equipment-mounted electrical devices, the anchorage design responsibility, the factory test witnessing policy, the manufacturer's field services, startup, training, delivery and storage, the warranty term, and the spare parts basis. Nothing here restates them. {note}
+
+## A slide gate is closed a few times a year and is expected to hold a channel dry each time, against a head it has never carried since the plant was commissioned, so that a crew can enter the channel behind it. The things that fail are the ones the schedule did not state and the shop did not test: a slide that bows under an unseating head it was not designed for, a seal that was fitted to a frame the concrete pulled out of plane, a stem that buckled between guides set too far apart, a lift that a single operator cannot turn at the design head. That is why this standard is prescriptive about the design heads, the leakage allowance, the stem, the lift effort, and the tolerance of the concrete the frame meets, and permissive about the material, the invert, the seals, and the lift type the engineer selects by service. {note}
+
+## The AWWA gate standards divide by material and by duty. AWWA C560 describes the cast iron slide gate with bronze seating faces and adjustable wedges, the gate utilities bought for most of a century. AWWA C561, AWWA C562, and AWWA C563 describe fabricated slide gates of stainless steel, aluminum, and composite, with self-adjusting ultra-high-molecular-weight polyethylene seats, designed for a seating and an unseating head that can rise above the top of the gate. AWWA C513 describes the lighter open-channel fabricated-metal slide and weir gate whose design head does not exceed the top of its frame. There is no AWWA standard for flap gates or stop logs; this standard writes their requirements against the material standards and the practice of the plants that use them. {note}
+
+## Gates shall conform to the design standard selected in the datasheet and shall be designed for the seating head and the unseating head indicated for each gate on the gate schedule.
+
+## Gates, stop logs, and their seals in contact with water intended for drinking shall be certified to NSF/ANSI/CAN 61 and NSF/ANSI/CAN 372 for every wetted component, including the seats, the seals, and the stem lubricant.
+
+## The following are outside this scope and are governed by the companion standards named. {note}
+- Electric, pneumatic, and hydraulic actuators, floor stands and bench stands bought separately from the gate, and the extension stems and stem guides between the gate stem and a separately bought stand or actuator: [[sync/valve-and-gate-actuators]]
+- A gate that modulates against a process variable in a control loop, with its positioner: [[sync/control-valves-and-actuators]]
+- The liquid-retaining structure, its blockouts, the setting and holding in the forms of the items this standard furnishes to be cast in, the concrete placed around them, and their grouting once set: [[sync/water-retaining-concrete-structures]], [[sync/cast-in-place-concrete]], and [[sync/concrete-accessories]]
+- Post-installed anchors into hardened concrete: [[sync/post-installed-anchors]]; non-shrink grout under an anchor-mounted frame: [[sync/non-shrink-grout]]
+- The outfall headwall or end wall a flap gate is mounted on: [[sync/site-concrete-structures]]; the storm sewer behind it and the outfall end treatment: [[sync/storm-drainage]]
+- Site and perimeter slide gates in fencing under ASTM F1184: [[sync/fencing-and-gates]]
+- Duct and damper slide gates in air and dust-collection systems: [[sync/louvers-and-dampers]] and [[sync/dust-and-fume-collection]]
+- Butterfly valves and eccentric plug valves: [[sync/butterfly-valves]] and [[sync/eccentric-plug-valves]]
+- The wall pipe or process pipe a flap gate or a thimble connects to, its flange bolting, and its gasket: [[sync/ductile-iron-process-piping]] and [[sync/steel-and-stainless-process-piping]]
+- Common process administrative and execution provisions: [[sync/common-work-results-process]]
+- Field-applied finish coatings over a shop coating: [[sync/high-performance-coatings]]
+- Gate tags and the equipment identification nameplate: [[sync/mechanical-identification]]
+
+## Radial, roller, and bulkhead gates for dams and intake structures, elastomer duckbill check valves used in place of flap gates, screening and grit equipment, clarifier mechanisms, and overhead cranes and hoists are not yet owned by a SynC standard; water storage tanks are governed by [[sync/water-storage-tanks]]. Timber stop logs cut and fitted on site are outside this standard, which covers manufactured stop log sections with seals. {note}
+
+# Referenced Standards {toc}
+
+## Gates, stop logs, materials, and installation shall comply with the latest adopted edition of each of the following unless a specific edition is cited.
+
+## 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 C513 | Open-Channel, Fabricated-Metal Slide Gates and Open-Channel, Fabricated-Metal Weir Gates |
+| AWWA C560 | Cast-Iron Slide Gates |
+| AWWA C561 | Fabricated Stainless-Steel Slide Gates |
+| AWWA C562 | Fabricated Aluminum Slide Gates |
+| AWWA C563 | Fabricated Composite Slide Gates |
+| 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 C550 | Protective Interior Coatings for Valves and Hydrants |
+| ASTM A126 | Gray Iron Castings for Valves, Flanges, and Pipe Fittings |
+| ASTM A240 / A240M | Chromium and Chromium-Nickel Stainless Steel Plate, Sheet, and Strip |
+| ASTM A276 / A276M | Stainless Steel Bars and Shapes |
+| ASTM A479 / A479M | Stainless Steel Bars and Shapes for Use in Boilers and Other Pressure Vessels |
+| ASTM A193 / A193M | Alloy-Steel and Stainless Steel Bolting for High Temperature or High Pressure Service |
+| ASTM A194 / A194M | Carbon Steel, Alloy Steel, and Stainless Steel Nuts for Bolts for High Pressure or High Temperature Service |
+| ASTM F593 | Stainless Steel Bolts, Hex Cap Screws, and Studs |
+| ASTM F594 | Stainless Steel Nuts |
+| ASTM A380 / A380M | Cleaning, Descaling, and Passivation of Stainless Steel Parts, Equipment, and Systems |
+| ASTM A967 / A967M | Chemical Passivation Treatments for Stainless Steel Parts |
+| ASTM B209 / B209M | Aluminum and Aluminum-Alloy Sheet and Plate |
+| ASTM B221 | Aluminum and Aluminum-Alloy Extruded Bars, Rods, Wire, Profiles, and Tubes |
+| ASTM B584 | Copper Alloy Sand Castings for General Applications |
+| ASTM B98 / B98M | Copper-Silicon Alloy Rod, Bar, and Shapes |
+| ASTM D4020 | Ultra-High-Molecular-Weight Polyethylene Molding and Extrusion Materials |
+| ASTM D2000 | Rubber Products in Automotive Applications (elastomer seal classification) |
+| AWS D1.2 / D1.2M | Structural Welding Code: Aluminum |
+| AWS D1.6 / D1.6M | Structural Welding Code: Stainless Steel |
+| NSF/ANSI/CAN 61 | Drinking Water System Components: Health Effects |
+| NSF/ANSI/CAN 372 | Drinking Water System Components: Lead Content |
+
+# Submittals {toc}
+
+## Action Submittals {toc}
+
+### The Contractor shall submit the following for the Engineer of Record's review and return before any gate or stop log is released for manufacture:
+
+- Product data for each gate and stop log type, identifying the design standard, the frame, slide, guide, seat, seal, stem, lift, and fastener materials with their ASTM designations, and the stop log section material
+- Shop drawings for each gate, identified by its mark on the gate schedule, showing the opening and the slide dimensions, the seating and unseating design heads, the mounting and the thimble or anchor bolt layout, the invert configuration, the seal arrangement, the stem diameter, thread, and guide spacing, the lift or the actuator mounting interface, the position indicator, and the loads delivered to the structure at the frame, the stem guides, and the lift
+- Setting templates and dimensions for every thimble, embedded guide, and cast-in anchor bolt, issued to the concrete trade before the forms that receive them are built
+- Design verification for each gate on the basis indicated under Quality Assurance, stating the slide deflection, the stem buckling check, and the lift thrust at the design heads
+- Thrust data for each gate to be power actuated or operated from a separately furnished floor stand, stating the operating thrust at the seating and the unseating head, the stem diameter and thread, and the mounting interface
+- Stop log drawings showing the section height, the section weight, the seals, the lifting devices, and the storage rack
+- Finish and coating data for each material, including the AWWA C550 compliance statement for coated cast iron and the NSF/ANSI/CAN 61 listing where the gate is in potable water service
+- A field test plan identifying the leakage test head, the method of measuring leakage, the operation test, and the record form
+
+```datasheet
+label: Action Submittals Required
+type: checkbox
+options:
+ - "Product data by gate and stop log type"
+ - "Shop drawings per gate mark with loads to the structure"
+ - "Thimble, guide, and anchor bolt setting templates"
+ - "Design verification per gate"
+ - "Thrust data and mounting interface for actuated and stand-operated gates"
+ - "Stop log, lifting device, and storage rack drawings"
+ - "Finish and coating data"
+ - "Field test plan"
+default:
+ - "Product data by gate and stop log type"
+ - "Shop drawings per gate mark with loads to the structure"
+ - "Thimble, guide, and anchor bolt setting templates"
+ - "Design verification per gate"
+ - "Thrust data and mounting interface for actuated and stand-operated gates"
+ - "Stop log, lifting device, and storage rack drawings"
+ - "Finish and coating data"
+ - "Field test plan"
+constraint: all_of
+```
+
+### Manufacture of a gate shall not begin until the submittal covering that gate has been returned by the Engineer of Record.
+
+### Setting templates shall be issued to the concrete trade before the formwork that receives the thimble, guide, or anchor bolt is built, and the Contractor shall record the date each template was issued.
+
+### A thimble template reviewed after the wall it belongs in has been poured is a drawing of a blockout that will be chipped. The date of issue is recorded so that a thimble set out of position can be traced to a late template or to a crew that set it without one, instead of being argued over when the frame does not fit. {note}
+
+## Closeout Submittals {toc}
+
+### The Contractor shall submit the following at substantial completion, before the gates and stop logs are accepted:
+
+- Shop assembly and test reports for every gate, identified by gate mark and serial number, recording the operation test and any shop leakage test with its head and result
+- Signed and dated field leakage test records for every slide gate and weir gate, recording the test head, the measured leakage, the allowance, and the result
+- Field operation test records for every gate, recording the turns from closed to open, the effort at the handwheel or crank, the position indicator agreement, and the seal contact
+- A record of the as-set position and elevation of every thimble, embedded guide, and anchor-mounted frame, noting any departure from the setting template
+- Operation and maintenance data for each gate and stop log type, including seal replacement, seat adjustment, stem lubrication, and the stop log lifting procedure
+- Spare parts receipt signed by the Owner's representative
+
+```datasheet
+label: Closeout Submittals Required
+type: checkbox
+options:
+ - "Shop assembly and test reports by gate mark"
+ - "Field leakage test records"
+ - "Field operation test records"
+ - "Record of as-set thimbles, guides, and frames"
+ - "Operation and maintenance data"
+ - "Spare parts receipt"
+default:
+ - "Shop assembly and test reports by gate mark"
+ - "Field leakage test records"
+ - "Field operation test records"
+ - "Record of as-set thimbles, guides, and frames"
+ - "Operation and maintenance data"
+ - "Spare parts receipt"
+constraint: all_of
+```
+
+# Quality Assurance {toc}
+
+## Single-Source Responsibility {toc}
+
+### The slide gates, weir gates, and flap gates of each design standard furnished under this standard shall be the product of a single manufacturer.
+
+### Each gate, its stem, its stem guides, its stem cover, its manual lift where self-contained, its thimble or anchor bolts, and the mounting interface for any separately furnished actuator or floor stand shall be furnished, shop assembled, adjusted, and tested by the gate manufacturer as a unit.
+
+### Stop logs, their guides, their lifting devices, and their storage rack for each channel shall be the product of a single manufacturer.
+
+### A gate shipped as a frame and a slide, with a stem from one supplier and a lift from another, arrives with nobody responsible for the thrust the stem must carry, the stops that keep the slide off the invert seal, or the indicator that is supposed to read closed when the seals touch. The gate manufacturer is the only party who knows the seating load of its own gate, so the stem and the lift are sized and mounted where that number is known. {note}
+
+## Design Verification {toc}
+
+### The design of each gate for its seating and unseating heads shall be verified on the basis indicated in the datasheet, and the verification shall be submitted with the shop drawings.
+
+```datasheet
+label: Gate Design Verification
+type: radio
+options:
+ - "Manufacturer's certification of design in accordance with the governing standard, with the slide deflection, stem, and lift thrust values stated"
+ - "Design calculations for each gate sealed by a professional engineer licensed in the state of the project"
+```
+
+### The governing standards set the stress and deflection limits and the stem and lift criteria, and a manufacturer that builds to them certifies each gate against them from its own design tables, which is what most projects accept because the gate is a standard product of a known design. Sealed calculations are bought where the gate is large, where the unseating head is high relative to the slide span, where the gate is a seismic or a life-safety isolation point, or where the Owner's standard requires a sealed design for every embedded item; they add an engineer's time to each gate and change nothing on a gate that was already within the standard. {note}
+
+### Where the parties disagree whether a gate design satisfies the governing standard at the scheduled heads, the Engineer of Record shall make the initial determination.
+
+## Welding and Fabrication {toc}
+
+### Stainless steel gates, frames, thimbles, and stop logs shall be welded in accordance with AWS D1.6 and aluminum gates and stop logs in accordance with AWS D1.2, by welders qualified under the project welding program of [[sync/welding-requirements]].
+
+### Stainless steel components shall be fabricated with tooling, abrasives, and handling surfaces that have not been used on carbon steel, and shall be cleaned and passivated after fabrication in accordance with ASTM A380 and ASTM A967.
+
+### Carbon steel ground into a stainless frame rusts on the first wet day and the rust streak is read as a failed gate; the shop keeps the two apart, and the passivation removes what the shop missed. {note}
+
+# Service Conditions {toc}
+
+## Gate Schedule {toc}
+
+### The opening width and height, the invert elevation, the seating head, the unseating head, the service fluid, and the location of each gate shall be as indicated on [[drawing: the gate schedule]].
+
+### Whether each location receives an upward-opening slide gate, a downward-opening weir gate, a flap gate, or a set of stop logs shall be as indicated on [[drawing: the gate schedule]].
+
+### Whether each slide gate and weir gate is wall-mounted over an opening or channel-mounted in embedded guides shall be as indicated on [[drawing: the gate schedule]].
+
+### Whether each slide gate and weir gate is self-contained, with the lift carried on a yoke integral with the frame, or non-self-contained, operated by a floor stand or actuator supported on the structure, shall be as indicated on [[drawing: the gate schedule]].
+
+### The operator of each gate, whether the manual lift of this standard, a floor stand, or an electric, pneumatic, or hydraulic actuator furnished under [[sync/valve-and-gate-actuators]], shall be as indicated on [[drawing: the gate schedule]].
+
+### The backflow head each flap gate closes against shall be as indicated on [[drawing: the gate schedule]].
+
+### Size, head, and mounting are properties of each opening in a structure, and a standard that asserts any of them has decided the hydraulics and the wall. The gate schedule carries them per mark, and this standard carries what every gate of a given material and type has in common. {note}
+
+## Design Heads and Leakage {toc}
+
+### Each slide gate and weir gate shall be designed for the seating head and the unseating head indicated for it on the gate schedule, measured from the invert of the opening to the water surface, with the slide, the frame, the guides, the stem, and the lift stressed within the limits the governing design standard allows at each head.
+
+### A seating head loads the slide against the frame and the water does the sealing; an unseating head pushes the slide away from its seats and the seals and the guides do it alone. The same gate leaks more and bows more under an unseating head, which is why the two are scheduled separately and a gate that can see pressure from either side carries both. A head that rises above the top of the gate, as at a conduit through a wall, is a wall-mounted gate under AWWA C560, C561, C562, or C563; a head that stays below the top of the frame, as in an open channel, is within AWWA C513. {note}
+
+### Leakage past a closed slide gate or weir gate under its seating head shall not exceed the allowance indicated in the datasheet, per foot of seating perimeter.
+
+```datasheet
+label: Allowable Leakage Under Seating Head
+type: range
+unit: gpm/ft
+options:
+ min: 0
+ max: 0.5
+ setpoints: [0, 0.05, 0.1, 0.2, 0.5]
+default: 0.1
+constraint: max
+```
+
+### Leakage past a closed slide gate or weir gate under its unseating head shall not exceed the allowance indicated in the datasheet, per foot of seating perimeter.
+
+```datasheet
+label: Allowable Leakage Under Unseating Head
+type: range
+unit: gpm/ft
+options:
+ min: 0
+ max: 0.5
+ setpoints: [0, 0.05, 0.1, 0.2, 0.5]
+default: 0.2
+constraint: max
+```
+
+### The fabricated-gate standards allow a leakage on the order of a tenth of a gallon per minute for each foot of seating perimeter under seating head, and twice that under unseating head, and a gate built to them meets those values without special order, which is why they are the defaults. A tighter allowance is bought for a gate that isolates a channel for confined entry, a chemical contact basin, or a clearwell, and it costs a resilient seal on every edge and a shop leakage test to prove it; zero leakage is a procurable claim for a flush-bottom gate with resilient seals on all four sides, and it is held only while the seals are new. A looser allowance is accepted on a gate that diverts flow between channels that are both wet, where a few gallons a minute go nowhere. {note}
+
+### The leakage allowance of a cast iron gate under AWWA C560 shall be the allowance that standard states for a metal-seated gate, where the datasheet allowance is tighter than the standard permits for that gate.
+
+## Exposure {toc}
+
+### The fasteners, stem, stem guides, and lift of every gate in a wastewater wet well, a headworks, a grit chamber, a sludge channel, or a chemical contact basin shall be of stainless steel of the type the gate manufacturer rates for the atmosphere of that space, and not less resistant than the gate they serve.
+
+### Stems, stem guides, stem covers, and lifts installed outdoors shall be rated by their manufacturer for continuous service at [[parameter: site-ambient-temperature-minimum]] and at [[parameter: site-ambient-temperature-maximum]], and the lubricant in an outdoor lift shall be rated for the same range.
+
+### Seat and guide clearances of fabricated gates installed outdoors or in an unheated structure shall accommodate the thermal movement of the ultra-high-molecular-weight polyethylene seats between [[parameter: site-ambient-temperature-minimum]] and [[parameter: site-ambient-temperature-maximum]] without binding the slide at either extreme.
+
+### Ultra-high-molecular-weight polyethylene grows and shrinks with temperature several times as much as the stainless frame it sits in, and a seat fitted tight in a heated shop binds the slide on the first hot afternoon or opens a gap on the first cold night. The manufacturer sets the clearance from the temperature range of the site, which is a project fact. {note}
+
+### Gates, stems, and lifts installed where they are submerged, including in a wet well that floods to the operating floor, shall be furnished with lifts sealed for submergence and with stem threads and guides that operate wet.
+
+# Gate Material and Design Standard {toc}
+
+## Governing Design Standard {toc}
+
+### The material and the design standard to which slide gates and weir gates are manufactured shall be as indicated in the datasheet.
+
+```datasheet
+label: Slide Gate Material and Design Standard
+type: select
+options:
+ - "Fabricated stainless steel, AWWA C561, with AWWA C513 for open-channel gates"
+ - "Fabricated aluminum, AWWA C562, with AWWA C513 for open-channel gates"
+ - "Fabricated composite, AWWA C563"
+ - "Cast iron with bronze seating faces, AWWA C560"
+default: "Fabricated stainless steel, AWWA C561, with AWWA C513 for open-channel gates"
+```
+
+### A fabricated stainless steel gate is what nearly every new water and wastewater structure is built with: it is light enough to set without a crane in most sizes, its polyethylene seats adjust themselves, it needs no coating, and it is the gate every current manufacturer builds first, which is why it is the default. A fabricated aluminum gate weighs half as much again less, costs less, and is selected for open channels, weir gates, and low heads in water that does not attack aluminum, at the cost of isolation from the concrete and a lower stiffness that limits the span at a given head. A composite gate is selected for a chemical contact basin, a brine channel, or a seawater intake where stainless steel pits, and it is built to a stiffness rather than a strength and costs the most. A cast iron gate with bronze seats and wedges is the gate a utility with a century of them already in service buys to match its stock of parts and its crews' habits, and it is selected where a thick-walled gate under a very high head is wanted; it weighs the most, is coated, and its wedges are adjusted by hand. {note}
+
+### Fabricated metal gates whose design head does not exceed the top of the frame may conform to AWWA C513 in place of the fabricated-gate standard selected, and every gate whose seating or unseating head rises above the top of the frame shall conform to AWWA C560, C561, C562, or C563 as selected.
+
+## Stainless Steel Type {toc}
+
+### Where fabricated stainless steel is selected, the frame, slide, guides, yoke, thimble, and reinforcing of each gate shall be of the stainless steel type indicated in the datasheet.
+
+```datasheet
+label: Stainless Steel Type
+type: radio
+options:
+ - "Type 304 or 304L"
+ - "Type 316 or 316L"
+```
+
+### Type 304 resists treated water, raw water, and the atmosphere of a water plant gallery, and it is the stock stainless of every plate thickness and shape. Type 316 adds molybdenum for chloride and sulfide service, which is the atmosphere of a wastewater headworks or wet well, a chloraminated contact basin, a coastal plant, and a brine or softener waste channel, at a higher cost per pound. The low-carbon grades are used where the gate is welded, because the heat-affected zone of the standard grade loses corrosion resistance in some exposures. Neither type is the norm across the water and wastewater services this standard covers, so neither is defaulted. {note}
+
+### Stainless steel plate and sheet shall conform to ASTM A240, and bars and shapes to ASTM A276 or ASTM A479, in the type selected.
+
+### Stainless steel fasteners shall conform to ASTM F593 and ASTM F594, or to ASTM A193 Grade B8 or B8M with ASTM A194 Grade 8 or 8M nuts, of the type matching the gate.
+
+## Aluminum Alloys {toc}
+
+### Where fabricated aluminum is selected, plate shall conform to ASTM B209 in alloy 5052-H32 or 6061-T6, and extrusions to ASTM B221 in alloy 6061-T6 or 6063-T6.
+
+### Aluminum gate and stop log surfaces in contact with concrete, grout, or a dissimilar metal shall be isolated by a bituminous coating, a neoprene isolator, or a non-metallic washer at every bearing and every fastener.
+
+### Bare aluminum against fresh concrete is etched by the alkalinity of the cement, and bare aluminum against stainless steel in water forms a galvanic couple in which the aluminum is consumed at the contact line. The isolation breaks both at every point the metals meet, and the stainless fasteners of an aluminum gate are isolated the same way. {note}
+
+## Cast Iron Gates {toc}
+
+### Where cast iron is selected, frames, slides, wedges, and thimbles shall be gray iron castings conforming to ASTM A126 Class B, and seating faces shall be bronze conforming to ASTM B584 or ASTM B98, machined and secured to the frame and slide so that the faces mate over the full seating perimeter.
+
+### Cast iron gates shall be furnished with adjustable side wedges, and with top and bottom wedges where the unseating head requires them under AWWA C560, so that the seating faces close to the leakage allowance in the closed position and clear in travel.
+
+### Seating faces on a cast iron gate are machined bronze on both the frame and the slide, and the wedges press one against the other as the slide reaches the bottom of its travel. A wedge set too tight scores the faces on every stroke, and one set too loose leaks; the adjustment is made at the shop assembly and again in the structure after the frame is grouted, which is why the field test records the seal contact. {note}
+
+## Composite Gates {toc}
+
+### Where fabricated composite is selected, the frame and slide shall be of fiberglass-reinforced plastic conforming to AWWA C563, with a resin the manufacturer rates for the service fluid and for ultraviolet exposure where the gate is outdoors, and with every fastener, pin, and stem of stainless steel of the type the manufacturer rates for the service.
+
+### Composite gates shall be designed to the deflection limit the governing standard sets, and the slide reinforcing shall be stated on the shop drawings.
+
+# Slide Gate Frame, Slide, and Seals {toc}
+
+## Frame and Guides {toc}
+
+### The frame of each slide gate and weir gate shall be a rigid welded or cast unit that carries the slide in guides along its full travel, with the guides extending above the opening far enough that the slide is held in the guides over not less than one half its height at the fully open position.
+
+### Guides shall be fitted with replaceable ultra-high-molecular-weight polyethylene guide bars on fabricated gates and with machined bearing surfaces on cast iron gates, so that the slide runs without metal-to-metal contact in travel.
+
+### The frame of a wall-mounted gate shall be furnished with a flange for mounting on a wall thimble or a machined back for mounting on anchor bolts, as selected under the Wall Thimbles and Anchorage section of this standard, and the frame of a channel-mounted gate shall be furnished with guides for embedding in the channel walls.
+
+### Self-contained gates shall be furnished with a yoke integral with the frame that carries the lift, designed for the full thrust of the lift at the effort limit without transmitting the thrust to the thimble or the anchor bolts.
+
+## Slide {toc}
+
+### The slide shall be a plate reinforced with welded or formed members so that its deflection under the greater of the seating and the unseating head does not exceed the limit the governing design standard sets, which for AWWA C561 is 1/360 of the span.
+
+### The slide shall be guided so that it cannot leave the guides at any position of travel, including the fully open position under the design head.
+
+### The stem connection to the slide shall be a nut pocket or a lug designed for the full thrust of the lift in both directions, and the connection shall transmit no bending into the stem when the slide is cocked in its guides to the limit of the guide clearance.
+
+### A slide that deflects more than its seals can follow leaks along the sides first and at the bottom corners next, and the leakage grows with the head until the seal is unloaded entirely. The deflection limit is what makes the leakage allowance a number the gate can meet at the scheduled head rather than at the head it happened to be tested at. {note}
+
+## Invert Configuration {toc}
+
+### The invert of each slide gate shall be configured as indicated in the datasheet.
+
+```datasheet
+label: Invert Configuration
+type: radio
+options:
+ - "Flush bottom, with a resilient invert seal set flush with the channel floor"
+ - "Conventional, with a frame invert member and seat across the bottom of the opening"
+```
+
+### A flush-bottom gate has no frame member across the bottom of the opening; the slide closes against a resilient seal set in the channel floor, so grit, rags, and sludge pass under the open gate and nothing collects against a sill. It is the gate of a wastewater or sludge channel and of any opening whose invert is the channel floor, and it depends on the invert seal being set true to the floor and the concrete finished flat under it. A conventional invert carries a seat across the bottom of the opening on the frame itself, so the gate seals on four sides of its own frame and the floor finish does not matter; it is the gate of a conduit through a wall, of a clean water channel, and of any gate whose opening is above the floor. Neither is the norm across the services this standard covers. {note}
+
+### Flush-bottom gates shall be furnished with a resilient invert seal mounted on the bottom of the slide or on the frame invert member, and the frame shall be set so that the seal closes against the finished channel floor without a step or a gap.
+
+## Seats and Seals {toc}
+
+### Fabricated gates shall be furnished with self-adjusting seats of ultra-high-molecular-weight polyethylene conforming to ASTM D4020 on the frame and the slide, retained so that the seats are replaceable without removing the frame from the structure.
+
+### Fabricated gates shall be furnished with a resilient seal across the top of the opening, of a J-bulb, P, or wedge section, mounted on the frame or the slide so that it is compressed by the slide in the closed position and clears the slide in travel.
+
+### Resilient seals shall be of neoprene or ethylene propylene diene monomer rubber classified under ASTM D2000 and rated by the seal manufacturer for the service fluid, and seals in potable water service shall be of a compound certified to NSF/ANSI/CAN 61.
+
+### Seals on the invert and the sides of a weir gate, and the top seal of a slide gate under an unseating head, shall be mounted so that the pressure of the water presses the seal against the slide rather than away from it.
+
+### A seal that the head pushes closed seals better as the head rises, and a seal that the head pushes open leaks more as the head rises; which way the seal faces is decided by which side of the gate the unseating head is on, and a gate that sees both heads carries seals that work both ways. The polyethylene seats carry the slide and take the wear, and the rubber seals do the sealing where the seats alone would weep; the two are separate parts so that each is replaced on its own schedule. {note}
+
+### Seat and seal retaining hardware shall be of the same stainless steel type as the gate or of a stainless steel the manufacturer rates as galvanically compatible with it.
+
+# Stems and Lifts {toc}
+
+## Stem Type {toc}
+
+### Slide gates and weir gates shall be furnished with stems of the type indicated in the datasheet.
+
+```datasheet
+label: Stem Type
+type: radio
+options:
+ - "Rising stem"
+ - "Non-rising stem"
+default: "Rising stem"
+```
+
+### A rising stem lifts with the slide and shows the gate position by how far it stands above the lift, so the operator reads the gate from across the room and the threads stay above the water in a cover where they are lubricated and inspected; it is the stem of nearly every gate in a plant, which is why it is the default. A non-rising stem turns in a nut on the slide and stays at one height, so it fits under a low ceiling, a walkway, or a hatch, and its threads run wet in the channel where they wear and where the position is read only from an indicator on the lift. {note}
+
+### Rising stems shall be furnished with a stem cover and a position indicator as required under this section, and non-rising stems shall be furnished with a position indicator on the lift that reads the slide position through full travel.
+
+## Stem Material and Threads {toc}
+
+### Stems shall be of the stainless steel indicated in the datasheet, conforming to ASTM A276 or ASTM A479, of solid round bar through the full length.
+
+```datasheet
+label: Stem Material
+type: radio
+options:
+ - "Type 304 stainless steel"
+ - "Type 316 stainless steel"
+derived: "the gate material and the stainless steel type selected for the gate"
+default: derived
+```
+
+### The stem is the one part of a gate that is loaded, threaded, and wetted at once, so its grade follows the atmosphere of the space the way the frame's does: a Type 304 frame carries a Type 304 stem, a Type 316 frame a Type 316 stem, and a cast iron, aluminum, or composite gate carries the stainless stem the space calls for. A project whose stems see a worse exposure than its frames, as where a lift stands in a chlorine room above a clean water channel, records a different grade here. {note}
+
+### Stem threads shall be machine cut or rolled 29° Acme or stub Acme threads of the diameter and pitch the governing design standard requires, with a finish that runs in a bronze lift nut without galling.
+
+### Stems shall be designed to carry, in compression, the thrust the lift delivers at the effort limit multiplied by the factor the governing design standard requires, without buckling at the stem guide spacing furnished, and the stem diameter and the guide spacing shall be stated on the shop drawings.
+
+### Stems in more than one section shall be joined by threaded or keyed couplings of the same material as the stem, pinned so that the coupling cannot back off in either direction of rotation.
+
+### Stem guides shall be furnished at the spacing the governing design standard requires for the stem diameter, so that the slenderness ratio of the stem between guides does not exceed 200, with a guide not more than the spacing above the lift nut on a self-contained gate.
+
+### Stem guides shall be adjustable in two directions, bushed with bronze or ultra-high-molecular-weight polyethylene, and mounted on brackets of the gate material anchored to the structure with stainless steel anchors.
+
+### A stem is a slender column loaded in compression every time the gate is closed against its head, and it buckles between guides before it yields. The guide spacing is set by the stem diameter and not by the convenience of the wall, which is why the spacing is on the shop drawings and the guides are adjustable so that the stem runs straight once the frame is set. {note}
+
+## Stem Cover and Position Indicator {toc}
+
+### Rising stems shall be furnished with a stem cover of the type indicated in the datasheet, extending the full rise of the stem above the lift, vented and capped against rain.
+
+```datasheet
+label: Stem Cover
+type: radio
+options:
+ - "Clear polycarbonate or acrylic tube with a position-indicating scale"
+ - "Aluminum or stainless steel pipe with a position indicator window"
+default: "Clear polycarbonate or acrylic tube with a position-indicating scale"
+```
+
+### A clear tube shows the stem and its scale from anywhere on the floor and is the cover nearly every plant gate carries, which is why it is the default; it yellows under years of sun and is replaced as a part. A metal pipe cover survives a plant where covers are struck by equipment and hoses, and it shows the position only at the window. {note}
+
+### Each lift shall be furnished with a position indicator that reads the slide position continuously from fully closed to fully open and that is visible from the operating position.
+
+## Manual Lifts on Self-Contained Gates {toc}
+
+### Each self-contained gate shall be furnished with a manual lift of the type indicated in the datasheet, mounted on the yoke of the gate.
+
+```datasheet
+label: Manual Lift Type on Self-Contained Gates
+type: select
+options:
+ - "Handwheel lift, direct drive"
+ - "Handwheel-operated geared lift"
+ - "Crank-operated geared lift"
+ - "Lift with a 2 in. square operating nut for a portable operator"
+derived: "the operating thrust at the greater of the seating and unseating head and the effort limit at the handwheel or crank"
+default: derived
+```
+
+### The lift is sized from the thrust the gate needs at its worst head and the effort an operator is allowed to apply, so the type follows from those two numbers: a direct handwheel moves a small gate at a low head, a geared handwheel or crank multiplies the effort where the thrust is more than a wheel can deliver within the limit, and a square nut replaces the wheel where the gate is reached with a portable operator or a tee wrench from a hatch. A project that wants every lift to match, or that keeps portable operators rather than wheels, records the type here instead. {note}
+
+### Manual lifts shall be furnished with a bronze lift nut conforming to ASTM B584 threaded to the stem, running in ball or roller thrust bearings above and below the nut, in a housing sealed against the entry of water and dust and fitted with a grease fitting.
+
+### Geared lifts shall be self-locking so that the slide holds any position between fully open and fully closed under the design head without creep, and the gearing shall run in grease in a housing sealed as the lift nut housing is sealed.
+
+### Each lift shall open the gate with an effort at the rim of the handwheel or at the crank handle not exceeding the value indicated in the datasheet, with the gate under the greater of its seating and unseating heads.
+
+```datasheet
+label: Operating Effort at the Handwheel or Crank
+type: range
+unit: lb
+options:
+ min: 25
+ max: 60
+ setpoints: [25, 30, 40, 50, 60]
+default: 40
+constraint: max
+```
+
+### A 40 lb pull is the limit the fabricated-gate standards set for a handwheel or a crank, and it is the effort an operator sustains for the dozens of turns a gate takes to open, which is why it is the default. A lower limit is bought where the gates are operated by one person on every shift, or where the Owner's safety program sets a lower manual-handling limit, and it costs a lower gear ratio and more turns. A higher limit is accepted on a gate that is opened once a year by a crew. {note}
+
+### The direction of rotation to open shall be marked on the lift housing, and each lift shall open counterclockwise unless the gate schedule indicates otherwise for the project.
+
+### Manual lifts shall be furnished with adjustable mechanical stops at the fully open and fully closed positions that carry the full lift output without transmitting it to the slide or the seals.
+
+## Mounting Interface for Separately Furnished Operators {toc}
+
+### For each gate operated by an electric, pneumatic, or hydraulic actuator or by a floor stand furnished under [[sync/valve-and-gate-actuators]], the gate manufacturer shall furnish the operating thrust at the seating head, the operating thrust at the unseating head, the stem diameter, the thread form and pitch, the number of turns through full travel, and the maximum thrust the stem and the slide connection withstand.
+
+### The thrust data furnished shall be the basis on which the actuator or the floor stand is sized under [[sync/valve-and-gate-actuators]], and the gate manufacturer shall confirm in writing that the selected operator's rated thrust does not exceed the maximum thrust of the stem.
+
+### The gate manufacturer shall furnish the stem to the top of the stem guide nearest the gate on a non-self-contained gate, with a coupling at its end that the extension stem under [[sync/valve-and-gate-actuators]] matches, and the yoke, the actuator mounting flange, and the stem nut on a self-contained gate that is power actuated.
+
+### Actuators conforming to AWWA C542 or AWWA C541 shall be mounted on the gate by the gate manufacturer where the gate is self-contained, with the open and closed stops set and the assembly cycled through full travel before shipment.
+
+### The maximum stem thrust is the number that protects the gate from its own actuator. An electric actuator with its torque switch set high bends a stem into its guides on the first stall against a closed slide, and the gate manufacturer is the only party who knows where that limit is. {note}
+
+# Weir Gates {toc}
+
+## Weir gates shall be downward-opening gates of the material and design standard selected for slide gates, with the slide lowered by the stem to pass flow over its top edge and raised to close.
+
+## The top edge of a weir gate slide shall be straight and level within 1/16 in. across its width and shall be finished without a burr, so that the slide edge serves as the weir crest at every position.
+
+## Weir gates shall seal on the two sides and the invert of the opening with resilient seals mounted so that the head presses the seals against the slide, and the frame shall extend below the invert far enough to guide the slide at its lowest position.
+
+## Weir gates shall be furnished with a lift that holds the slide at any position between fully raised and fully lowered without creep, and with a position indicator graduated so that the crest elevation is read from the indicator.
+
+## A weir gate meters flow by its crest, and the crest is the top of the slide, so a slide edge that is out of level by an eighth of an inch across a six foot gate passes a different flow at each end and the indicator reads a crest that exists nowhere. The level tolerance and the graduated indicator are what make a weir gate a flow control rather than a slide gate installed upside down. {note}
+
+# Flap Gates {toc}
+
+## Flap Gate Construction {toc}
+
+### Flap gates shall be constructed as indicated in the datasheet, designed to close against the backflow head indicated for each gate on the gate schedule and to open under the forward head the manufacturer publishes.
+
+```datasheet
+label: Flap Gate Construction
+type: select
+options:
+ - "Cast iron body and cover with bronze seats"
+ - "Fabricated stainless steel with a resilient seal"
+ - "Fabricated aluminum with a resilient seal"
+```
+
+### A cast iron flap gate with bronze seats is the flap gate of the outfall and the storm pump station: heavy enough to close itself against a surge, seated metal to metal so that debris cannot cut a seal, and tolerant of being underwater for decades, at a weight that needs a crane and a cover that takes a head of several inches to open. A fabricated stainless steel flap gate with a resilient seal opens at a lower forward head, seals tighter, and resists a wastewater or brackish exposure that pits a cast iron body, at a higher cost and with a seal that is replaced. A fabricated aluminum flap gate is the lightest and lowest cost, opens at the lowest head, and is selected for a clean water or storm application in a structure where corrosion of aluminum is not a concern. {note}
+
+### Flap gate covers shall be hinged on pins of stainless steel of the type the manufacturer rates for the service, in bushings of bronze or ultra-high-molecular-weight polyethylene, so that the cover swings freely and seats evenly without adjustment.
+
+### Flap gate hinges shall be of the configuration indicated in the datasheet.
+
+```datasheet
+label: Flap Gate Hinge
+type: radio
+options:
+ - "Double-pivot hinge links"
+ - "Single-pivot hinge"
+```
+
+### A double-pivot hinge carries the cover on two links so that the cover swings away from the seat before it rotates, lifts clear of debris on the seat, and seats flat under the backflow head whatever its angle; it is the hinge of the cast iron flap gate and of any flap gate over 12 in. A single-pivot hinge is simpler and is the hinge of a small fabricated gate where the cover is light enough to seat on its own. {note}
+
+### Flap gates shall be furnished with a cover that the manufacturer rates to open under the forward head stated on the shop drawings, and the shop drawings shall state the head at which the cover begins to open and the head at which it is fully open.
+
+## Flap Gate Mounting {toc}
+
+### Flap gates shall be mounted as indicated in the datasheet.
+
+```datasheet
+label: Flap Gate Mounting
+type: select
+options:
+ - "Flange-mounted on a wall thimble or a pipe flange"
+ - "Spigot-mounted into the end of the pipe"
+ - "Wall-mounted on anchor bolts with a sealed back"
+```
+
+### A flange mount bolts the gate to a thimble cast in the wall or to the flange of the wall pipe, so the gate is removed and reseated by unbolting it, and it is the mount of a new structure where the thimble or the wall pipe is cast in. A spigot mount sets the gate into the end of the pipe itself and is used at an existing outfall where there is no flange and no room to anchor to the wall. A wall mount on anchor bolts puts the gate on the face of a headwall around an opening, with a sealant or a gasket between the back of the gate and the wall, and it is the mount of an existing headwall and of a gate larger than the pipe it closes. {note}
+
+### Where a flap gate is flange-mounted on a wall thimble, the thimble shall be furnished with the gate under the Wall Thimbles and Anchorage section of this standard, and where it is mounted on the flange of a wall pipe, the wall pipe is furnished under the piping standard and the gate manufacturer shall furnish the flange drilling to it.
+
+### Where a flap gate is mounted on an outfall headwall, the headwall and the opening through it are furnished under [[sync/site-concrete-structures]], and the gate manufacturer shall furnish the anchor bolt template and the opening dimension the headwall is formed to.
+
+# Stop Logs {toc}
+
+## Stop Log Sections {toc}
+
+### Stop logs shall be furnished as manufactured sections of the material indicated in the datasheet, stacked in guides to the height indicated for each location on the gate schedule.
+
+```datasheet
+label: Stop Log Material
+type: select
+options:
+ - "Aluminum extrusions"
+ - "Fiberglass-reinforced plastic pultrusions"
+ - "Fabricated stainless steel"
+```
+
+### Aluminum stop logs are the lightest of the three for the stiffness they give, are extruded in one piece with their seal grooves, and are what most plant channels are furnished with; they are isolated from the concrete and from stainless guides at every contact. Fiberglass pultrusions weigh about the same, never corrode, and are selected for a chemical, brine, or seawater channel where aluminum pits, at a lower stiffness that limits the span at a given head. Fabricated stainless steel stop logs carry the highest head at a given span and resist the wastewater atmosphere that attacks aluminum, and they weigh the most, which limits the section height a crew can handle. {note}
+
+### Each stop log section shall span the full width of the guides, shall be designed for the head indicated for the location on the gate schedule with the section at the bottom of the stack, and shall nest with the section above and below it so that the stack cannot displace under the head.
+
+### No stop log section shall weigh more than the value indicated in the datasheet, and the section height shall be chosen so that the weight is met.
+
+```datasheet
+label: Stop Log Section Weight
+type: range
+unit: lb
+options:
+ min: 25
+ max: 300
+ setpoints: [25, 50, 75, 100, 150, 200, 300]
+constraint: max
+```
+
+### Stop logs are handled by hand from the top of the channel with a hook, and a section a crew cannot lift is one that is left in the rack while the channel floods. A section under a hundred pounds is set by two people without a hoist, a lighter one by a single operator, and a heavier one only where a hoist or a crane reaches the guides; the weight follows the Owner's handling practice and the hoist at the location rather than the gate, which is why it is not defaulted. {note}
+
+## Stop Log Seals and Guides {toc}
+
+### Each stop log section shall be furnished with a resilient seal along its bottom edge that seals against the section below or against the invert, and with resilient seals at each end that seal against the guides, of a compound classified under ASTM D2000 and rated for the service fluid.
+
+### Stop log guides shall be mounted as indicated in the datasheet, of the same material as the stop logs or of stainless steel isolated from aluminum logs, extending from the invert to the top of the channel wall.
+
+```datasheet
+label: Stop Log Guide Mounting
+type: radio
+options:
+ - "Embedded guides cast into the channel walls"
+ - "Surface-mounted guides on anchor bolts"
+```
+
+### Embedded guides are set in blockouts and grouted flush with the wall under the water-retaining structure standard, so the channel wall is smooth and nothing projects into the flow; they are the guides of a new structure. Surface-mounted guides bolt to the face of the wall and are the guides of an existing channel and of a channel whose wall was not blocked out, at the cost of a projection into the channel and an anchor bolt pattern in the wall. {note}
+
+### Guides shall be furnished with a bottom stop or a sill that locates the lowest section on the invert seal, and with a top entry that admits a section without binding.
+
+## Stop Log Lifting Devices and Storage {toc}
+
+### Stop logs shall be furnished with the lifting devices indicated in the datasheet, each rated for the heaviest section it handles.
+
+```datasheet
+label: Stop Log Lifting Devices Furnished
+type: checkbox
+options:
+ - "Manual lifting hooks with handles, one pair for each stop log width"
+ - "Lifting beam with self-latching hooks for hoist or crane handling, one for each stop log width"
+ - "Lifting lugs or handles on each section"
+default:
+ - "Manual lifting hooks with handles, one pair for each stop log width"
+ - "Lifting lugs or handles on each section"
+constraint: all_of
+```
+
+### Stop logs shall be stored on a rack as indicated in the datasheet, sized to hold every section furnished for the channels it serves.
+
+```datasheet
+label: Stop Log Storage Rack
+type: select
+options:
+ - "Wall-mounted rack adjacent to the guides it serves"
+ - "Freestanding rack serving several channels"
+ - "Not furnished, stored in the guides or by the Owner"
+```
+
+### Where a freestanding storage rack is selected, its location shall be as indicated on [[drawing: the process mechanical plans]].
+
+### A rack on the wall beside the guides keeps the logs where they are used and within reach of the crew that drops them, and it needs wall space beside every channel. A freestanding rack in one place holds the logs for several channels of the same width and leaves the walls clear, at the cost of carrying the logs to the channel. Leaving the logs in the guides stores them where they are needed and blocks the channel they sit in, and some Owners store them in a building on pallets instead; neither needs a rack. {note}
+
+### Stop log sections shall be marked with the channel and the position in the stack they belong to, by stamping or engraving on a surface visible with the section in the rack.
+
+# Wall Thimbles and Anchorage {toc}
+
+## Frame Attachment {toc}
+
+### Wall-mounted slide gates, weir gates, and flange-mounted flap gates shall be attached to the structure as indicated in the datasheet.
+
+```datasheet
+label: Wall-Mounted Frame Attachment
+type: select
+options:
+ - "Cast-in wall thimble, with the frame bolted to the thimble flange"
+ - "Anchor bolts, with the frame grouted to the wall"
+ - "Anchor bolts, with a compressible seal between the frame and the wall"
+```
+
+### A wall thimble is cast into the wall and gives the frame a machined flange to bolt to, so the frame is set true to the thimble rather than to the concrete, the seal between gate and wall is a gasket on a flange, and the gate is removed by unbolting it; it is the attachment of a new structure, and it has to be in the forms before the pour. Anchor bolts with a grouted frame set the frame on bolts and fill the gap between the frame and the wall with non-shrink grout, so the frame bears on the wall over its full back and the wall's own flatness matters less; they are the attachment of an existing wall and of a new wall where no thimble was cast. Anchor bolts with a compressible seal set the frame against the wall on a mastic or a gasket without grout, so the gate is removed without chipping grout, and they depend on the wall being flat to the tolerance this standard sets. No attachment is the norm across new and existing structures, so none is defaulted. {note}
+
+### Anchor bolts, nuts, and washers for frames, stem guides, lifts, stop log guides, and storage racks shall be stainless steel of the type matching the gate, and shall be furnished by the gate manufacturer with the setting template.
+
+## Wall Thimbles {toc}
+
+### Wall thimbles shall be of the profile indicated in the datasheet, with a flange machined flat and drilled to match the gate frame, and with a water stop flange or ribs cast or welded around the body to key into the concrete.
+
+```datasheet
+label: Wall Thimble Profile
+type: radio
+options:
+ - "F-section, with the mounting flange flush with the wall face"
+ - "E-section, with the mounting flange projecting from the wall face"
+default: manufacturer
+```
+
+### Wall thimbles shall be of the material indicated in the datasheet.
+
+```datasheet
+label: Wall Thimble Material
+type: select
+options:
+ - "Type 304 stainless steel"
+ - "Type 316 stainless steel"
+ - "Cast iron, ASTM A126 Class B"
+derived: "the gate material and the stainless steel type selected for the gate"
+default: derived
+```
+
+### An F-section thimble has its flange flush with the face of the wall and its body cast into the wall thickness, so the gate frame sits on the wall face and the thimble is sized to the wall; an E-section thimble carries its flange proud of the wall and is used where the wall is thin or where the gate is set off the face. Each manufacturer builds its thimbles one way for each gate size and wall thickness, and the choice follows the manufacturer's design. The thimble material follows the gate it carries: a stainless gate on a stainless thimble of the same type, a cast iron gate on a cast iron thimble, and an aluminum or composite gate on the stainless thimble the space calls for, because a thimble of a different metal from the frame bolted to it corrodes one or the other at the flange. {note}
+
+### Wall thimbles shall be furnished with a gasket of a compound classified under ASTM D2000 between the thimble flange and the gate frame, full face, and with stainless steel studs or bolts in the thimble flange.
+
+### The thimble length shall be not less than the wall thickness at the opening, and where the thimble is shorter than the wall, the gate manufacturer shall state on the setting template which face of the wall the flange is set flush with.
+
+## Anchor Bolts for Anchor-Mounted Frames {toc}
+
+### Anchor bolts for frames mounted without a thimble shall be of the type indicated in the datasheet, set from the gate manufacturer's template.
+
+```datasheet
+label: Anchor Bolts for Anchor-Mounted Frames
+type: radio
+options:
+ - "Cast-in anchor bolts set in the forms from the template"
+ - "Adhesive anchors set in the hardened wall"
+```
+
+### Cast-in anchor bolts are set in the forms from the template and are in the wall before the gate arrives, so the frame bolts to them without drilling and the bolts develop their load in sound concrete; they depend on the template being right and on the crew setting it. Adhesive anchors are drilled after the wall is poured, from the frame itself or from the template, so the frame fits where it is drilled; they are the anchors of an existing wall and of a new wall whose pour came before the gate submittal, and they are qualified and installed under the post-installed anchor standard. {note}
+
+### Cast-in anchor bolts shall be set and held in the forms under [[sync/water-retaining-concrete-structures]] and [[sync/concrete-accessories]], and adhesive anchors shall be qualified, installed, and inspected under [[sync/post-installed-anchors]].
+
+### Where a frame is grouted to the wall, the grout shall be non-shrink grout furnished and placed under [[sync/non-shrink-grout]], filling the space between the frame and the wall over the full back of the frame without voids.
+
+## Tolerance of the Mounting Surface {toc}
+
+### The face of the wall under an anchor-mounted frame, and the face of a thimble flange after the concrete is placed, shall be flat within the value indicated in the datasheet over the full extent of the frame, and plumb within the same value over the height of the frame.
+
+```datasheet
+label: Mounting Surface Flatness
+type: range
+unit: in.
+options:
+ min: 0.0625
+ max: 0.25
+ setpoints: [0.0625, 0.125, 0.1875, 0.25]
+default: 0.125
+constraint: max
+```
+
+### A frame bolted to a wall that is out of plane is pulled out of plane with it, and the seats and seals that were fitted in the shop to a flat frame then seal in some places and gap in others. An eighth of an inch over the frame is what a formed wall finished for a gate meets and what a self-adjusting seat absorbs, which is why it is the default; a tighter tolerance is bought where the frame is set on a compressible seal without grout and the seal has nothing else to take up, and a looser one is accepted where the frame is grouted and the grout takes up the wall. {note}
+
+### The gate manufacturer shall state the flatness and plumb tolerance of this standard on every setting template, and the concrete trade shall finish the mounting surface and set the thimble to it under [[sync/water-retaining-concrete-structures]].
+
+### Where a mounting surface or a thimble flange is found outside the tolerance after the concrete is placed, the Contractor shall correct it by grinding, by a grouted bedding under the frame, or by resetting the thimble, as the Engineer of Record directs in writing, at the Contractor's cost.
+
+### This standard furnishes the thimble, the anchor bolts, and the template, and it sets the tolerance the concrete must meet; the structure, the blockout, the setting and holding of the thimble and the embedded guides through the pour, and the grouting of embedded frames and guides once set are the work of [[sync/water-retaining-concrete-structures]]. The two meet at the template and the tolerance, which is why both are on the setting drawing. {note}
+
+# Finishes {toc}
+
+## Stainless Steel and Aluminum Finishes {toc}
+
+### Stainless steel gates, thimbles, stems, guides, and stop logs shall be furnished unpainted, with the surface cleaned and passivated after fabrication as required under Quality Assurance, and shall not be coated.
+
+### Aluminum gates and stop logs shall be furnished with the finish indicated in the datasheet on exposed surfaces, with the bituminous or isolating coating required under Gate Material and Design Standard on surfaces in contact with concrete or a dissimilar metal.
+
+```datasheet
+label: Aluminum Finish
+type: radio
+options:
+ - "Mill finish"
+ - "Clear anodized"
+default: "Mill finish"
+```
+
+### Mill finish aluminum weathers to a stable gray oxide in a plant and needs nothing, which is why it is the finish of nearly every aluminum gate and stop log and the default. A clear anodized finish holds the bright appearance and resists the staining of a chemical splash, and it is bought where the gate is in view in a finished space or where the Owner's standard calls for it, at a cost per piece and with the anodized layer broken at every cut edge made after anodizing. {note}
+
+## Cast Iron Coatings {toc}
+
+### Ferrous surfaces of cast iron gates, thimbles, and flap gates, except machined seating faces, wedge faces, and flange faces, shall be coated at the factory with the system indicated in the datasheet.
+
+```datasheet
+label: Coating System on Cast Iron Gates
+type: select
+options:
+ - "Fusion-bonded epoxy, AWWA C550"
+ - "Two-part liquid epoxy, AWWA C550"
+ - "Coal tar epoxy"
+default: manufacturer
+```
+
+### Fusion-bonded epoxy is applied as a powder to a heated casting and bonds to blast-cleaned iron as a hard, holiday-free film, and it is applied only in a shop equipped to heat a casting the size of a gate frame. Two-part liquid epoxy to the same standard is sprayed in any coating shop and is the system a manufacturer uses on castings too large to heat. Both meet AWWA C550 and 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, which is why the manufacturer's standard is the default. Coal tar epoxy is the thick black coating of the submerged outfall flap gate and the sewer gate, where no NSF listing is needed and the film thickness is what is wanted. {note}
+
+### Coatings on cast iron gates in potable water service shall be certified to NSF/ANSI/CAN 61.
+
+### Coating 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 gate.
+
+### Where the finish scheme of the plant calls for a field-applied finish coat over a cast iron gate or a lift, the shop coating shall be compatible with the finish coat system furnished under [[sync/high-performance-coatings]], and the gate manufacturer shall state the surface preparation the finish coat requires.
+
+# Factory Assembly and Testing {toc}
+
+## Shop Assembly {toc}
+
+### Each slide gate and weir gate shall be completely assembled in the shop with its frame, slide, seats, seals, stem, stem guides, and lift or actuator mounting, and shall be cycled through full travel by its own lift or by a shop operator before shipment.
+
+### During the shop assembly the seat and seal contact shall be checked around the full seating perimeter in the closed position, the wedges of a cast iron gate shall be adjusted, the stops shall be set, and the position indicator shall be set to read closed when the seals are in contact.
+
+### A gate shipped assembled and then disassembled for shipment shall be match-marked so that it is reassembled in the structure to the shop setting, and the match marks shall be shown on the shop drawings.
+
+### Flap gates shall be assembled in the shop with their covers hung, and each cover shall be checked to seat around its full perimeter with the gate upright.
+
+### A gate that was assembled for the first time in the structure is adjusted in the structure by a crew that has never seen it seal, against seals that were fitted to nothing. The shop assembly is where the seal contact is proved with the frame flat on a table, and the match marks are what let the crew put it back the way it was. {note}
+
+## Shop Leakage Test {toc}
+
+### Slide gates and weir gates shall receive a shop leakage test on the basis indicated in the datasheet.
+
+```datasheet
+label: Shop Leakage Test
+type: select
+options:
+ - "Shop operation test only, with the leakage test performed in the structure"
+ - "Shop leakage test at the design seating head on every gate"
+ - "Shop leakage test on selected gates only"
+default: "Shop operation test only, with the leakage test performed in the structure"
+```
+
+### Where the shop leakage test is limited to selected gates, the gates to be tested shall be as indicated on [[drawing: the gate schedule]].
+
+### A slide gate is proved by its leakage in the structure, against the wall it is bolted to, and most projects accept the shop operation test and the seal contact check in its place because the shop test is made against a flat table that the wall will not match; this is why the operation test is the default. A shop leakage test on every gate puts each gate under its seating head in a test fixture and measures what passes, and it is bought where a tight allowance was selected, where the gate isolates a confined space, or where the Owner has had a shipment fail in the structure. Testing designated gates buys the proof for the few gates whose failure would drain a basin, which the gate schedule names. {note}
+
+### Where a shop leakage test is performed, it shall be made with the gate closed under the design seating head for not less than the duration the governing design standard prescribes, and the measured leakage shall not exceed the allowance indicated in the datasheet for the seating head.
+
+### A gate that fails a shop test shall be corrected and retested, and the Contractor shall bear the cost of the correction and the retest.
+
+### Witnessing of shop tests, the notice given, and the cost of attendance shall be as provided under [[sync/common-work-results-process]].
+
+# Installation {toc}
+
+## Setting of Embedded Items {toc}
+
+### Thimbles, embedded guides, and cast-in anchor bolts shall be delivered to the concrete trade with their setting templates before the forms that receive them are built, and shall be set, braced, and held through the pour under [[sync/water-retaining-concrete-structures]] so that the flange or the guide is within the tolerance of this standard after the concrete is placed.
+
+### A thimble or an embedded guide shall not be used as a form for the opening, shall be braced internally against distortion by the concrete, and shall be checked for position, plumb, and flatness before the pour and again after the forms are stripped.
+
+### Thimble flanges shall be covered and the stud threads protected during the pour, and the flange shall be cleaned of concrete before the gate is set.
+
+### A thimble that the concrete pushed out of flat during the pour is found when the frame is bolted to it and the seals gap at one corner, and it is corrected by grinding the flange or by shimming the frame, neither of which is what the gate was designed for. The internal bracing and the two checks are what keep the flange where the template put it. {note}
+
+### Grouting of embedded guides and of blockouts around embedded frames shall be performed under [[sync/water-retaining-concrete-structures]] after the guide or frame has been set, aligned, and checked by the gate installer, and the grout shall be non-shrink grout under [[sync/non-shrink-grout]].
+
+## Setting of Gates and Stop Log Guides {toc}
+
+### Each gate frame shall be set on its thimble or its anchor bolts plumb, level, and square, with the guides parallel and the invert at the elevation on the gate schedule, and the frame shall be checked against the tolerance of this standard before the bolts are tightened.
+
+### Frame bolts on a thimble shall be tightened evenly in a crossing pattern in not fewer than three passes with the gasket in place, and anchor bolt nuts on a grouted frame shall not be tightened to their final torque until the grout has reached the strength the grout manufacturer publishes for load application.
+
+### The slide shall be installed in the frame, or the frame and slide set as shipped, and the gate shall be cycled through full travel by hand before the stem is connected to the lift.
+
+### Stem guides shall be set so that the stem runs straight and true between the slide and the lift, with the guide bushings centered on the stem at every guide, and the stem shall turn freely through full travel before the lift is loaded.
+
+### The lift on a non-self-contained gate, the floor stand, and the extension stem between the gate stem and the stand shall be set under [[sync/valve-and-gate-actuators]], and the gate installer shall verify the alignment of the gate stem with the stand before the extension stem coupling is made.
+
+### Stop log guides shall be set plumb and parallel at the spacing the stop log sections require, with the sill or bottom stop at the invert elevation on the gate schedule, and each stop log section shall be trial-fitted through the full height of the guides before the guides are grouted or their anchor bolts are tightened.
+
+### Aluminum frames, guides, and stop logs shall be isolated from the concrete and from stainless steel at every contact as required under Gate Material and Design Standard, and the isolation shall be in place before the item is set.
+
+### Each gate shall be installed with clearance for the lift, the handwheel or crank, the stem cover at full rise, and the removal of the seals and the seats, not less than the manufacturer's published service clearance.
+
+## Field Testing {toc}
+
+### Each slide gate and weir gate shall be operated through full travel after installation, and the Contractor shall record the turns from closed to open, the effort at the handwheel or crank, the agreement of the position indicator with the slide position, and the seal contact around the perimeter in the closed position.
+
+### A gate whose effort at the handwheel or crank exceeds the limit indicated in the datasheet, whose stem binds at any guide, or whose position indicator does not agree with the slide, shall be corrected by the Contractor before the leakage test.
+
+### Each slide gate and weir gate shall be leakage tested in the structure with the gate closed and the structure on the seating side filled to the seating head indicated on the gate schedule, or to the highest head the structure can hold during the leakage test of the structure under [[sync/water-retaining-concrete-structures]] where that is lower, and the leakage past the gate shall be measured and shall not exceed the allowance indicated in the datasheet.
+
+### Where a gate carries an unseating head on the gate schedule, the leakage test shall be repeated with the head on the unseating side where the structure can be filled on that side, and the leakage shall not exceed the allowance indicated in the datasheet for the unseating head.
+
+### Leakage shall be measured by collecting the flow past the closed gate in a container of known volume over a timed interval, or by the rate of rise in the dry channel where the channel is closed at its far end, and the method shall be the one stated in the field test plan.
+
+### The leakage test of a gate is made at the same time as the leakage test of the structure, because the structure has to be full to make the head and a basin is filled once. A gate test run against a lower head than the schedule proves the gate at that head only, and the record says so. {note}
+
+### Each flap gate shall be tested after installation by swinging the cover through its travel by hand, by checking that the cover seats around its full perimeter in the closed position, and, where the pipe can be charged, by observing that the cover opens under forward flow and closes against backflow.
+
+### Each set of stop logs shall be tested after installation by setting the full stack in the guides by the lifting devices furnished, filling the channel on one side to the head indicated on the gate schedule where the structure permits, and observing the leakage past the stack, and by removing the stack by the lifting devices furnished.
+
+### A gate or stop log set that fails a field test shall be corrected or replaced by the Contractor and retested, and the Contractor shall bear the cost of the correction, the retest, and the witnessing parties' attendance at the retest.
+
+### Field tests shall be witnessed, noticed, and reported as provided under [[sync/common-work-results-process]], and the manufacturer's representative shall attend the leakage test of the first gate of each type and size and of every gate designated for a shop leakage test.
+
+# Delivery, Storage, and Handling {toc}
+
+## Gates shall be shipped with the slide in the closed position, blocked against movement in the guides, with the seats and seals protected from abrasion, and with the stem shipped separately or removed where its length makes it liable to bending in transit.
+
+## Gates and stop logs shall be lifted by the frame, by lifting lugs the manufacturer provides, or by slings around the frame, and shall not be lifted by the stem, the lift, the handwheel, the slide, or the seals.
+
+## Gates, stop logs, and seals shall be stored off the ground on timbers or pallets, under cover, with resilient seals and polyethylene seats out of direct sunlight and clear polycarbonate stem covers protected from impact.
+
+## Stainless steel gates, thimbles, and stop logs shall be stored clear of carbon steel and shall not be set on carbon steel dunnage.
+
+## Each gate shall be delivered with its shop test report, its thimble gasket and bolts, its stem, stem guides, and stem cover, and its lift where self-contained, and the Contractor shall verify the delivery against the approved submittal before the gate is moved to the structure.
+
+## The Contractor shall bear the cost of repairing or replacing a gate or stop log damaged in delivery, storage, or handling, and a repair in place of replacement shall be made only with the Engineer of Record's written approval.
+
+# Warranty {toc}
+
+## The Contractor shall warrant each gate, stop log set, lift, and thimble against defects in materials and workmanship for the warranty period and under the warranty provisions of [[sync/common-work-results-process]].
+
+## A gate that leaks past its seals beyond the allowance indicated in the datasheet at or below its scheduled head, that binds in its guides, that cannot be operated within the effort limit indicated in the datasheet, or whose stem bends or whose seats or seals separate from the frame or slide within the warranty period shall be repaired or replaced by the Contractor at no cost to the Owner.
+
+## The Contractor shall bear the cost of draining and refilling the basin or channel a warranted repair requires, of the confined space entry the repair requires, and of repairing any other work damaged by the failure or by the repair.
+
+## The cost that goes unassigned in a gate warranty is never the gate. It is the basin that has to be drained to reach it and the process that has to be taken out of service while it is, and naming those costs is what makes the warranty worth having on a gate that cost less than the day of lost treatment. {note}
+
+# Spare Parts {toc}
+
+## The Contractor shall furnish the spare parts indicated in the datasheet, packaged, labeled with the gate mark and size they fit, and delivered to the Owner before substantial completion, under the spare parts basis selected in [[sync/common-work-results-process]].
+
+```datasheet
+label: Spare Parts Furnished
+type: checkbox
+options:
+ - "One set of resilient seals for each gate size and seal arrangement"
+ - "One set of polyethylene seats and guide bars for each gate size"
+ - "One lift nut and thrust bearing set for each lift size"
+ - "One set of stop log seals for each stop log width"
+ - "One stem cover for each stem cover size"
+ - "Two portable operators or tee wrenches for gates furnished with a square operating nut"
+default:
+ - "One set of resilient seals for each gate size and seal arrangement"
+ - "One set of stop log seals for each stop log width"
+constraint: all_of
+```
+
+## Spare parts shall be the products of the gate manufacturer and shall be interchangeable with the parts installed in the gates furnished.
+
+## The resilient seal is the one wearing part every fabricated gate has and the one a crew replaces with the frame in place, so a set per size is the spare that is used, and the stop log seal is replaced the same way. Seats and guide bars outlast several sets of seals, a lift nut is a long-lead part that is worth holding where the gate isolates something the plant cannot do without, and the portable operator is furnished because a gate with a square nut and no wrench within reach is a gate nobody can close. {note}
+
+## The spare parts list, with the manufacturer's part numbers, shall be included in the operation and maintenance data.