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451 – Rectangle Flap Gate with Rubber Flap

Model 451 flap gates use a rubber flap to release fluid while preventing backflow. Reinforced with rugged members usually made form stainless steel. Mounting to a wall thimble or pipe flange available.

Shape	Rectangle
Type	Flap Gate
Mounting Configurations	Channel-Mounted, Embedded, Thimble-Mounted, Wall-Mounted
Materials	Stainless Steel, Rubber
Size Range	12" x 12" typically up to 96" x 96" – but we can typically accommodate any custom needs.
Industries	Environmental Restoration Projects, Navigation Locks and Canals, Flood Control Systems, Hydroelectric Power Plants, Industrial Water Systems, Mining Industry, Irrigation Systems, Municipal Stormwater Systems, Water and Wastewater Treatment Plants
Series	400 Series

General Information

The 451 Series Flap Gates from Whipps, Inc. are engineered with a thick, reinforced rubber flap that flexes open under internal water pressure and seals tightly against a resilient seat to prevent backflow. This simple yet highly effective design makes the 451 model a dependable choice for a wide range of standard flow conditions where low unseating heads and quiet, cushioned operation are important.

Constructed with corrosion-resistant rubber reinforced by stainless steel members, the 451 models provide durability and longevity with minimal maintenance requirements. Its resilient seals are field-replaceable, ensuring reliable long-term performance without costly overhauls.

Whipps custom-fabricates 451 Flap Gates to accommodate virtually any opening (round, square, or wide) and offers multiple mounting options, including direct wall mounting, channel mounting, pipe flange connections, or wall thimble installations. This flexibility allows the 451 Series to fit seamlessly into municipal wastewater treatment systems, stormwater drainage channels, pump discharge lines, and other water management applications.

Product Advantages

Superior Performance

Whipps, Inc. guarantees lower leakage than that listed in AW WA C-SOI- Cast Iron Sluice Gates or the latest revision, AWWA C-560 – Cast Iron Slide Gates. Whipps, Inc. will guarantee leakage of no more than 0.05 gpm/ft of seal perimeter in seating head and unseating head conditions. Including high head service.

Cost

Fabricated stainless steel gates almost always cost less than cast iron gates. As the size of the gate increases, the price difference increases. This is due to the manufacturing process (e.g. casting of parts and subsequent machining) required to produce cast iron gates.

Strength

The ultimate strength of stainless steel is in excess of twice the ultimate strength of cast iron and stainless steel has approximately twice the modulus of elasticity of cast iron.

Durability

Stainless steel resists corrosion better than cast iron. The uv stabilized UHMW seat/seals that are utilized on our stainless steel gates are field proven to maintain shape and integrity in demanding applications. Whipps, Inc. tested the UHMW seatjseals to confirm the ability to withstand continuous operation in an abrasive environment. The testing consisted of 25,000 gate open/close cycles in an abrasive media while experiencing only negligible wear. (Test results available upon request)

Reliability

Unlike traditional cast iron gates, the slide will not “freeze” to the frame after long periods of inactivity. Whipps, Inc. stainless steel gates incorporate UHMW seat/seals to prevent any metal-to-metal contact between the slide and the frame.

Delivery

The fabrication process required to turn raw materials into a stainless steel gate is quicker than the casting and machining process required to turn raw materials into a cast iron gate

Self-Adjusting Seals

The Series 900 stainless steel gates have a self-adjusting seal system that completely eliminates the need for field adjustment. This seal system was developed with the understanding that many gates are installed in locations where field adjustment of wedges is not practical or possible. Another drawback to a wedged system is that wedge adjustment is an inexact science. Wedge adjustment when attempted by inexperienced personnel can lead to additional leakage, difficult gate operation and increased localized gate stresses. The self-adjusting seal system is a combination of durable UHMW seatjseals and a resilient static spring/seal. The UHMW seat/seals are shaped to form a low friction, yet tight, seal with the slide. The spring/seal serves two main purposes: First; it acts as a bulb seal etween the frame and the UHMW seat/seal and secondly; it acts as a “spring” to ensure continuous contact between the UHMW seat; seals and the slide. The spring/seal is stationary, similar to an O-ring seal. and it is protected from wear or damage from the movable slide by the UHMW seatjseals. (Wedges can be provided on our Series 900, but they are not recommended since they do not improve the performance of our gate.)

Low Maintenance

Stainless steel gates do not require periodic painting, and require less operator attention compared to cast iron gates.

Ease of Repair

In the unusual event that the seat/seals are damaged, they can be replaced in the field with common tools. The gate does not have to be removed from the wall. If the seating surface on a cast iron gate is damaged, the gate will have to be removed from the wall and shipped back to the manufacturer for re-manufacture.

Range of Sizes

The process to design and manufacture fabricated gates allows for a nearly unlimited range of sizes. This is not the case with cast iron gates since new patterns or modifications to existing patterns are required to accommodate unusual sizes.

Mounting Configurations

Gate frames may be embedded in the channel walls. mounted to a wall with anchor bolts, mounted to a pipe flange, or wall thimble. Wall thimble mounting is possible although it is usually only necessary for applications with high unseating heads. Gates can also be designed to mount to existing wall thimbles or existing pipe flanges. Flanged frames or flat frames are available for gates to cover square, rectangular or round openings in concrete structures.

Similar Items

3D Model of 451 Flap Gate Mounted to Pipe

451 – Pipe Flap Gate with Rubber Flap

Model 451 flap gates use a rubber flap to release fluid while preventing backflow. Reinforced with rugged members usually made form stainless steel. Mounting to a wall thimble or pipe flange available.

451 – Square Flap Gate with Rubber Flap

Model 451 flap gates use a rubber flap to release fluid while preventing backflow. Reinforced with rugged members usually made form stainless steel. Mounting to a wall thimble or pipe flange available.

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900 Series

Stainless Steel Gates

Telescoping & Butterfly Valves

Recent Stainless Steel Gate Water Control Equipment News & Updates

Did you know that Whipps, INC. offers custom solutions for almost any industry in need of industry standard water control equipment products? If you have a specific need, any questions or are not sure where to look, We'd urge you reach out to us.

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Our Product Series

Mounting Configurations

451 – Rectangle Flap Gate with Rubber Flap

Model 451 flap gates use a rubber flap to release fluid while preventing backflow. Reinforced with rugged members usually made form stainless steel. Mounting to a wall thimble or pipe flange available.

General Information

Product Advantages

Superior Performance

Cost

Strength

Durability

Reliability

Delivery

Self-Adjusting Seals

Low Maintenance

Ease of Repair

Range of Sizes

Mounting Configurations

Similar Items

451 – Pipe Flap Gate with Rubber Flap

Model 451 flap gates use a rubber flap to release fluid while preventing backflow. Reinforced with rugged members usually made form stainless steel. Mounting to a wall thimble or pipe flange available.

451 – Square Flap Gate with Rubber Flap

Model 451 flap gates use a rubber flap to release fluid while preventing backflow. Reinforced with rugged members usually made form stainless steel. Mounting to a wall thimble or pipe flange available.

Recent Stainless Steel Gate Water Control Equipment News & Updates