Do you know relief valve?

Let Ekgas introduce to you

What a Relief Valve Does

A relief valve automatically opens at a preset pressure to release excess fluid (gas or liquid), preventing damage or explosion. Once the pressure returns to a safe level, the valve closes again.

How It Works

1. Normal condition: The valve remains closed under system pressure.
2. Overpressure condition: When pressure rises above the set point, the spring or diaphragm inside the valve is overcome.
3. Pressure relief: The valve opens, allowing the fluid to escape.
4. Pressure restored: Once the pressure drops, the valve reseats and seals.

Main Components

• Inlet/Outlet ports – where the fluid enters and exits.
• Spring or diaphragm – provides the force to keep the valve closed until set pressure is reached.
• Adjusting screw – used to set the opening pressure.
• Seat and disc – sealing parts that open and close to control flow.

Applications

• Boilers and pressure vessels
• Compressors and pipelines
• Fuel gas systems
• Chemical and power plants

Types of Relief Valves

• Safety valve: for gas or steam; opens rapidly (“pop action”).
• Relief valve: for liquid; opens gradually as pressure rises.
• Pressure safety valve (PSV): general term for both.
• Pressure vacuum relief valve (PVRV): used in tanks to protect against both overpressure and vacuum.