FABRICATED GATES
SS-250
General
The gates shall be either self-contained with yoke and bench stand operators,
or non-self-contained with separate stem guides and operator, in accordance
with the requirements of these specifications. Specific configurations
shall be as noted on the gate schedule or as shown on the plans.
Frame and Guides
The gate frame shall be a rigid unit composed of stainless steel guide
rails with UHMW seats upstream and downstream. These shall form a tight
seal between the frame and the slide (disc). This tight seal shall provide
an allowable leakage rate of no more than .1 gallons per minute (GPM)
per peripheral foot of perimeter opening for seating heads and .2 GPM
per peripheral foot for unseating heads. Stainless steel retainer bars,
cross bars and head rails (for self-contained gate only) shall be provided.
The clear opening shall be the same size as the waterway, unless otherwise
specified. The guides will be of sufficient length to support two-thirds
of the height of the slide when in the full open position.
Slide Cover (Disc)
The slide cover (disc) shall be stainless steel plate reinforced with
structural shapes welded to the plate. The slide cover shall not deflect
more than 1/720th of the span of the gate under the maximum head. The
stem connection shall be either the clevis type, with structural members
welded to the slide and a bolt to act as a pivot pin, or a threaded and
bolted (or keyed) thrust nut supported in a welded nut pocket. The clevis
or pocket and yoke of the gate shall be capable of taking, without damage,
at least twice the rated thrust output of the operator at 40 pounds pull.
Flushbottom Closure
Gates shall be furnished with a flush seal arrangement. A resilient seal
with a minimum width of exposed face of ¾" shall be securely
attached to the frame along the invert, and shall extend to the depth
of the guide groove. The fabricated gates shall be Waterman SS-250 Series.
Materials
Frames, Rails, Cover Slides, Yokes Stainless Steel - ASTM A-276, Type
304 or 316, as specified Fasteners and Anchor Bolts Stainless Steel -
ASTM A-593 and 594, Type 304CW or 316CW, as specified Stems Stainless
Steel - ASTM A-276, Type 304 or 316, as specified Flushbottom Seals Rubber
- ASTM D-2000 BC 615/625 Grade BE 625 Seats Ultra High Molecular Weight
Polyethylene (UHMW) Finish Mill finish on all stainless steel surfaces
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