How Does a Venting Valve Work?

Basics

A venting valve is normally used on a system where gases build up. Any gas, even steam, can cause problems for a system if the pressure isn't released from time to time. This is what the venting valve is for. Opening the valve will allow the gas to escape and bring the pressure inside the pipe or container back to a normal level.

Setup

The valve is a simple set up consisting of a handle to open it with, the valve shell and the plug. The plug is inside the valve shell and is attached to the handle. When the handle is down the plug sits up against the seat of the valve, which is the part of the shell that attaches to the container or pipe. Depending on the type of gas, the plug may be made of metal, rubber or, in some cases, plastic.

Operation

The handle of the vent valve operates like a screw. When it is turned clockwise it tightens or goes down into the valve shell and when it is turned counterclockwise it rises up. The plug attached to the handle is forced down onto the seat when the handle is tightened, creating a seal and keeping gas from being released. When the handle is loosened, the plug rises with the handle and the gas can escape. If operated manually, gloves are generally used when opening and closing a vent valve, due to the pressure of the gas as well as heat in certain circumstances.