Choosing the right check valve for your water needs

In late 2021, a Brisbanebased utilities company approached Fluid Control Sales and Installations for a check valve solution on a sewer overflow structure they were reconditioning for the local council.

The company’s requirements were for a check valve that could be mounted on the outside of a 30” reinforced concrete pipe and fit within the space of a precast pipe culvert. It also needed to work reliably in an outlet with mud and mangroves, have a low opening pressure to compensate for the lack of gradient and would need no maintenance after installation.

After investigating solutions from various manufacturers, Fluid Control decided on a 30” Proco ProFlex™ Style 731 low-slope duckbill check valve made from a Neoprene elastomer with 316SS retaining clamps.

A duckbill check valve was chosen over an in-line or flap gate valve for its inherent ability to self-clean and discharge in an environment with tidal muds and mangroves. If the lower bill area on a duckbill check valve is blocked with mud or sand, the top half of the valve may still open and discharge the upstream water.

As this upstream flowing water continues to drain, it will erode the mud and sand that sits on the downstream side of the valve, clearing away the restriction and allowing the valve to return to function at full capacity.

The design of the low-slope duckbill means that any standing water inside the valve can drain away, preventing mosquito or vermin growth. The base of the valve would not contact the bottom area of the pipe culvert, which would inhibit the ability of the valve to seal shut on pressure reversal.

Fluid Control Sales and Installations worked around the Christmas and New Year shutdowns to supply this 30” Proco check valve on time for installation in early 2022, just before the Brisbane floods.

The experience Proco Products has with the production of elastomer materials means that the duckbill check valve has a design life of 35-50 years and is fitted with a barnacle and algae resistant coating that will not degrade with UV exposure.