When working with piping systems, you may often hear both non-return valve (NRV) and check valve being used. At first glance, they might sound like two different valves. But are they really the same? Or is there a difference worth noting? Let’s break it down in simple terms.
What is a Non Return Valve (NRV)
A non-return valve is a type of valve that allows fluid—whether liquid or gas—to flow in only one direction. Once the flow stops or tries to reverse, the valve closes automatically. This function prevents backflow, which can damage equipment or contaminate clean media.
NRVs are commonly used in:Water supply systems to prevent contamination.Pumps to stop backflow when the pump is turned off.Industrial pipelines where maintaining one-way flow is critical.
The key point is simple: an NRV ensures the fluid goes forward and never back.
What is a Check Valve
A check valve works on the exact same principle. It also stops reverse flow and ensures fluid moves in one direction only. Check valves can be found in almost every industry, from water treatment to oil and gas.
There are several types of check valves, such as:Swing check valves (with a hinged disc that swings open or closed).Lift check valves (disc lifts up or down with flow).Ball check valves (a ball acts as the closing mechanism).Wafer check valves (compact design for tight spaces).
So, What’s the Difference?
Here’s where things get interesting. The truth is: a non-return valve and a check valve are essentially the same thing. The main difference lies in the terminology.
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Non-return valve (NRV) is the more generic or descriptive term, often used in British English and in water-related industries.
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Check valve is the more widely used term, especially in American English and in industrial or mechanical contexts.
So, when someone says NRV, they’re talking about the same device that another person may call a check valve. Both serve the same purpose: to prevent backflow.
Post time: Sep-16-2025