How a failed Check/Non Return valve can damage your LPG pump

Started by General Moderator, Feb 17, 2023, 10:29 PM

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General Moderator

A Non-Return/Check Valve is one that allows liquid to flow in one direction only.

A Non-Return/Check Valve is usually installed in the return line of the pipework of an LPG Plant.

The purpose of the valve is to allow the excess gas pumped by the pump to flow back to the tank, in order to prevent the over-pressurization of the line and LPG pump.

The Non-Return/Check Valve is usually pre-set to a pressure at which it opens to allow the flow of gas, back to the tank.

When the pressure in the line increases and the pre-set pressure is attained, the valve system in the Non-Return/Check Valve opens and the liquid gas flows back to the tank.

The internal valve closes immediately the pressure in the line drops below the pre-set pressure of the Non-Return/Check Valve, thus preventing backflow from the tank.

How to know when the Non-Return/Check Valve fails to open

You will hear a continuous unusually loud sound from LPG pump when the internal valve of the Non-Return/Check Valve fails to open, when the pre-set pressure has been reached.

When the internal valve fails to open

When the internal valve system of the Non-Return/Check Valve is damaged and fails to open when the pressure in the line reaches the pre-set pressure, the excess gas in the line will be unable to return to the gas tank, resulting in the over-pressurization of the lines and LPG pump.

The sustained over-pressurization of the LPG pump will lead to the failure of the mechanical seal of the pump and cause gas leakage.


Turn off your LPG Pump and call your LPG engineer to address the problem.
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