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How does a gas regulator work?

How does a gas regulator work?

There are many different kinds of regulator, but they all work on the same principle. The simplest type is the single stage regulator, which reduces the gas pressure from the cylinder to the level required by the appliance in one go.


The basic components of every regulator comprise a spring, a thin flexible rubber or metal disc called a diaphragm, and a valve.


Although not every regulator has pressure gauges, we’ve included them here to help show how the pressure changes as gas enters and leaves the regulator.

Guide: How Gas Regulators Work

At Wonkee Donkee we have made a simple step-by-step guide on how gas regulators work. Our easy to follow guide includes images and detailed descriptions so you can follow the process from when gas enters the regulator through to when the gas leaves.

Step 1 - Gas enters regulator

When you attach the regulator to a cylinder and open the cylinder valve, high pressure compressed gas rushes through the inlet into the valve chamber.

Step 2 - Gas fills the chamber

The gas soon fills up the valve chamber, as shown by the inlet pressure gauge on the left.

Step 3 - Diaphragm moves down

When you turn the regulator control knob clockwise to increase the flow of gas, it presses down on the spring which in turn forces the diaphragm downwards. This then pushes the valve stem open.


Step 4 - Gas enters low pressure chamber

Opening the valve stem lets the gas flow into the low pressure chamber. The gas now pushes upwards against the diaphragm, creating an opposing force to the spring.

Step 5 - Diaphragm stabilises

When the upward force created by the pressure of gas under the diaphragm reaches the same level as the downward force exerted by the spring, the diaphragm stops moving and becomes steady.


This lets the gas start flowing at a smooth, even rate into the appliance.

Step 6 - Cylinder pressure drops

After a while the pressure in the cylinder starts to drop as the gas is used up. This has a knock-on effect on the pressure in the valve chamber, which also begins to weaken. 


As the force pressing up from below is reduced, the diaphragm begins to move downwards, pushed by the spring. This opens the valve wider, letting more gas into the low pressure chamber.

Step 7 - Outlet pressure rises

As the gas becomes concentrated in the low pressure chamber, the outlet pressure begins to rise, as shown by the gauge. There is now hardly any gas left in the inlet.

Step 8 - Cylinder empties

When the cylinder has run out of gas, or you turn the cylinder valve off because you’ve finished using the appliance, the inlet shuts off and both pressure gauges return to zero as the last of the gas leaves the regulator.

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