Types Of Check Valves And Their Uses

Jun 16, 2023 | News

Check valves are one-way flow control valves that allow fluid to flow in only one direction while preventing reverse flow. There are various types of check valves based on their design and construction.

Single Disc Wafer Check Valve

Wafer check valves feature a circular disc design that acts as a one-way flap or door. When flow moves in the allowed direction, the disc lifts off its seat and fluid flows through. In the reverse direction, the disc closes against the seat to prevent backflow.

Single disc wafer check valves are compact in design with the valve body and disc forming a single integrated “wafer” that fits between two adjacent flanges. They have no centerline bore or shell as typical check valves.

Single disc wafer check valve is as used where space is restricted, installation cost needs to be minimized and straight-through flow is required. They are commonly used in the chemical process, power and oil & gas industries.

Dual Plates Check Valve

F650 series cast steel check valve 2

Dual plates check valves feature two flexible circular plates instead of a single disc. The plates are spring loaded and act independently to provide a bubble-tight seal against reverse flow.

When flow moves in the allowed direction, the plates lift off their seat. In the reverse direction, the spring action causes the plates to deform and seal tightly against the seat.

Dual plates check valves offer advantages like higher pressure rating, reduced slamming effects, minimized friction and longer service life compared to single disc check valves. They provide a more reliable seal for liquids and gases.

Dual plates check valve is often as used in critical applications like boiler feedwater, compressed air, pipeline surge protection etc. where reliable reverse flow prevention is essential.

Flange Double Door Check Valve

Double door check valves feature two semi-circular flexible flap doors instead of a single disc or plates. When flow moves in the allowed direction, the doors move apart to form an opening. In the reverse direction, the doors close against each other to provide a seal.

Flange double door check valve has flanged ends which allow for easy installation between flanges. They are typically built with a cast iron, cast steel or stainless steel body depending on requirements.

Double door check valves provide benefits like minimal energy loss, low opening and closing shock, bubble-tight sealing and low friction even at high operating pressures.

They are suitable for a wide range of applications like water and wastewater systems, power plants, oil & gas pipelines etc. where reliable prevention of reverse flow is critical.