This is the most common non-return valve available and is manufactured from HDPE (High Density Polyethylene) with Stainless Steel 316 parts.
The construction is lightweight but very robust in its design. It can be mounted to a flat wall or on an angle. It can be suited for mounting onto a PN10 or PN16 flange and can also be spigot mounted using a flexible coupling or with a conical spigot.
The materials used also ensure that the maintenance required is minimal.
Sizes start from 100mm diameter and bespoke designs can be tailor made to suit the customer's requirements.
The Flap Valve seals using an EPDM rubber seal and a sponge EPDM seal between the back-plate and concrete headwall proving to be very reliable The Flap Valves can be incorporated for many applications like this double staged Flap Valve for an otter pass.
The standard Flap Valve design is based on a 5 metre water column short term over a 12 hour period and is gravity fed. Non-standard designs with higher water pressure are made to measure to suit your application. Flap Valves can also be designed for pump flow applications.