Rugged aluminum construction is combined with tough, flexible ultra-high molecular weight polyethylene (UHMW) seat/seals. This design achieves a very low level of leakage. Top gates can also be supplied in a similar rugged stainless steel design.


  • Frames: Stop Gate frames are designed to be embedded (Model 501), mounted on the face of a wall (Model 503) and mounted in an existing channel (Model 503-C). The side guides are a rugged aluminum extrusion with an easily replaceable polymer seating/sliding liner. The sill is also an aluminum extrusion with an easily replaceable neoprene flush seating surface.
  • Slides: The slide is constructed from flat aluminum plate, sufficiently reinforced for the design head conditions. An appropriate lifting handle is attached near the top of the slide.
  • Leakage: The superior design of the polymer seating surfaces has reduced leakage for these stop gates to 0.10 gallons per minute per foot of wetted perimeter when specified.


  • Quality Assurance: The stop gate shall be the product of a manufacturer having 10 years or more experience in the successful design and manufacture of low leakage stop gates under similar design conditions. All welds shall be performed by welders with AWS certification.
  • Performance: Maximum allowable leakage for the stop gates shall be 0.10 gallons per minute per linear foot of wetted perimeter regardless of the direction of the unbalanced head. Acceptable manufacturers: Whipps Inc., Athol Massachusetts, Series 501, 503, 503-C or Engineer approved equal.
  • Technical Information: In addition to submittal information required by other sections of these specifications, the stop gate manufacturer may be required to submit design calculations and supporting data for all gates showing stresses, loads and deflection for critical parts under design head conditions. At a minimum, these shall include operating load, slide deflection, slide bending stress and shear stress in stiffener welds.
  • Frame: The frame shall consist of 1/4" minimum thickness extruded aluminum (Alloy 6061-T6) incorporating ultra-high molecular weight polymer (UHMW) seat/seal facings on both the upstream and downstream sides of the slide. Each seat/seal will be shaped to provide two bearing surfaces and two sealing edges. The gate side guides and invert shall have a minimum weight of 4 lbs./ft. for wall mounted and 3 lbs./ft for embedded. The gate invert shall contain a removable neoprene seal. Seals attached to the slide will not be acceptable. All necessary assembly and anchor bolts shall be type 304 (type 316 optional) stainless steel and shall be provided by the gate manufacture.
  • Slide: The slide shall be minimum thickness of 1/4" aluminum plate (Alloy 6061-T6) reinforced with stiffeners as required so that at the design head the slide will not deflect more than 1/360 of its width and stress is limited to 7600psi. Slide stiffeners shall have a minimum weight of 2.5 lbs./ft. The slide shall be provided with a cast aluminum offset lifting handle. Dual lifting handles shall be provided on gates wider than 36”.
  • Painting: All aluminum in contact with concrete shall have a heavy shop coat of bitumastic paint.
  • (ANODIZING optional): All aluminum components shall be anodized in conformance with Aluminum Association Specification AA-C22-A41. The anodizing shall be 0.7 mil thick with a nickel acetate sealer.

For additional information, please contact our sales department.