Elgas LPG Gas Blog

Gas Regulator: LPG Gas Regulator, Gas Bottle Fittings, Adaptors & Connectors

A gas regulator provides a consistent and safe 2.75 kPa outlet gas pressure, as the LPG gas regulator controls the flow of gas from your gas bottles-cylinders to your gas appliance or equipment. Gas bottle fittings, gas regulators, changeover valves and pigtails can be confusing if you have never dealt with them before.

Learn all about LPG gas bottles, POL fittings, LPG gas regulators, gas bottle fittings, adaptors and more…

LPG Gas Regulator for LPG Bottles - How Does a Propane Gas Regulator Work

LPG Regulator for LPG Gas Bottles - Propane RegulatorLPG gas regulators work to automatically reducing high pressure gas to the required 2.75 kPa for LPG appliances or equipment. The pressure within a gas bottle can be 800-900 kPa vs the 2.75 kPa typically required by LPG gas appliances. A gas regulator is required to reduce this gas pressure with all LPG gas installation.

Please note that a propane gas regulator is the same as an LPG gas regulator.

LPG gas tank regulators for LPG bottles are usually factory pre-set to the standard operating pressure for gas appliances.

LPG gas regulators are sometimes referred to as cooking gas regulators, when used with cooking gas appliances.

This short video (8:29) explains all of the basics of LPG, LPG gas regulators and fittings...

Gas Bottle Fittings

LPG gas bottle fittings - automatic changeover valvesThe gas bottle fittings include the gas regulator, all the gas valves, piping and connectors required to build a complete LPG gas system, connecting the gas bottles to the appliances. Gas bottle fittings called "Pigtails" are flexible gas tubes that connect the gas bottles to the changeover valve or directly to the gas regulator.

Changeover valves determine from which gas bottle the gas is being taken.

Licensed gas fitters are required for all gas related work, involving gas regulators and gas bottle fittings, on homes and businesses.

BBQ Gas Bottle Fittings

BBQ Gas Bottle Fittings - regulator & hose assmeblyBBQ gas bottle fittings involve less components than home installations, with typical BBQ gas bottle fittings being a POL gas regulator and hose. The POL gas regulator and hose usually come as an assembly but hoses are also sold alone.

Camper valve adapters may also be required as BBQ gas bottle fittings if you have a camper valve gas bottle or appliance.

Some outdoor appliances also require Piezo electric ignitors, replacement valves, various BBQ gas bottle fitting adapters and gas fitting kits for natural gas BBQ conversions.

LPG is Stored Under Pressure

45kg gas bottles

LPG is stored under pressure as a liquid in a gas bottle.

It turns back into a gas when you release some of the pressure in the gas bottle by turning on your appliance.   

The pressure within a gas bottle can be 800-900kPa. 

This varies based on the ambient temperature, exposure to the radiant heat of the sun and the amount of gas remaining in the gas bottle. 

Bottle Pressure vs Appliance Pressure

However, the required appliance inlet pressure for Australian LPG gas appliances is typically only 2.75kPa. 

So, a gas regulator is required to reduce the pressure and ensure a consistent 2.75kPa is safely delivered from the gas bottle to your appliances.

LPG Gas Regulator - Reduces & Regulates the Pressure

An LPG gas regulator (LP Gas regulator) reduces the high gas pressure from the gas bottle, of over 600kPa (87 PSI) at room temperature, to the required 2.75kPa (0.4 PSI) pressure for the gas appliances.  LPG gas regulators are typically pre-set at the factory to the correct output pressure.

Gas regulators are an essential part of an LPG system, as without them regulating the pressure, the LPG would be unsafe to use.

LPG regulator controls LPG pressure - Pressure Temperature Chart
LPG gas regulators must reduce the high pressures as shown in the LPG Pressure chart above.

LPG regulator

The LPG das regulator shown (right or above) includes an automatic changeover valve.

Gas Bottle Regulator Sizes

Gas bottle regulator sizes vary depending on the gas load. Although the purpose of LPG gas regulators is the same, different gas load applications may require different gas bottle regulators sizes and types.

The gas demand of the appliances determines what gas bottle regulator size and type of LPG gas regulator is installed.   

For example, if the combined megajoule (MJ) rating of your home’s appliances is quite high, an LPG gas bottle regulator with a higher MJ rating size would be required.  

Commercial sized LPG gas regulators are completely different and frequently comprised of two separate units.

Also, please note that under no circumstances should a BBQ gas regulator ever be used on a home installation.

Gas Regulator Operation: How They Work - LPG Gas Regulator Functionality

Gas regulator operation starts with a diaphragm, which is a flexible rubber disc that responds to the gas regulator gas pressure changes and functions to modulate the flow of gas to the proper pressure. The gas regulator gas diaphragm works in combination with springs and other parts within the gas regulator. 

Gas regulator operation also works in conjunction with the gas regulator gas vent, which allows the diaphragm to move freely.

If the vent is obstructed, the gas regulator functionality will be impaired. 

The vent should remain free of dirt and debris to ensure the proper gas regulator operation.

Gas Regulator Gas Types - Gas Regulator Adjustment Controls

Acetylene regulator Gas typeThere are different gas regulator gas types for various gases. Some gas regulator types are pre-set for a specific gas pressure, like LPG and natural gas regulators. Still other gas regulator types have gas regulator adjustment controls and gauges for varying and monitoring the gas pressure.

Some gases, like acetylene, are reactive with certain types of metal. This means that the gas regulator must be manufactured from a specific material for a specific gas. See accompanying image of acetylene gas regulator gas type.

Gas Bottle Gas Regulator Types

There are different gas bottle gas regulator types based on the application.  Gas regulator types are rated for flow rate, with different size gas regulators for different gas loads. For example, you wouldn't use a BBQ gas bottle gas regulator for a whole house.

There are also two-stage gas regulators, with two separate gas regulators, when there is a long run of piping between the gas bottles and the application.

Gas Pigtails

copper pigtail for LPG installation

The gas bottles are connected by tubing, known as “pigtails”, to a changeover valve and the changeover valve is connected to the gas regulator.  

Pigtails can be made of solid copper, rubber or braided metal over a rubber interior. 

Copper is generally considered the best choice, as rubber and braided pigtails have a limited life span. 

Rubber pigtailAlso, pigtails can catch or trap debris over time so they should be replaced any time the gas regulator is replaced. 

Pigtails are "flexible" and will absorb the shock of sudden movement or jarring, if the installation is accidentally bumped or moved out of place.

Without the flexible gas regulator connection, the piping would be rigid and more susceptible to leaks caused by movement.

LPG Gas Changeover Valves

Manual LPG changeover valve

As the names imply, manual changeover valves require manual intervention while automatic changeover valves automatically switch between gas bottles to the gas regulator when the first bottle runs dry.

The changeover valve controls which gas bottle is in use, when two gas bottles are installed. 

Changeover valves come in two types, with manual (shown) and automatic changeover versions.

Gas Bayonet Connections

Wall mounted LPG bayonet connection

If you have a portable gas heater, it will be connected to your home LPG supplied using a bayonet connections. 

Bayonet connectors can be floor or wall mounted. 

The male connector, on the end of the heater hose, plugs into the female connector which is, in turn, connected to the LPG service piping. 

Please see:

How to Connect & Disconnect Gas Bayonet Fittings

Propane Piping - What Type of Pipe is Used for Propane - LPG

Flexible LPG gas pipe

A gas line runs from the gas regulator to your appliances. This gas line is the service piping. Propane pipe (LPG pipe) generally consists of copper tubing or plastic polyethylene propane piping.

The propane piping needs to be installed correctly and legally, in conjunction with the gas bottles, for the entire installation to be safe and serviceable.

Licensed Gas Fitter is Required

Please remember that all gas installations must be carried out by a licensed gas fitter. 

You can find a licensed gas fitter in your area by using our TradeFinder™ map tool.

How to Operate Gas Bottle Changeover Valves

In Australia, you would typically have two 45kg gas bottles.  

These are connected by tubing to a changeover valve that determines which gas bottle is currently in use.  

Changeover valves can be automatic or manual and is connected to the gas regulator.

Automatic Gas Changeover Valves

Automatic Changeover Valve

Automatic changeover valves automatically switch from one gas bottle to another, to the gas regulator, when one is empty.  

There are different manufacturers and models of the automatic valves but they all have a visual indicator, which typically turns red when the first bottle is empty. 

This is when you need to order gas, before the second bottle runs dry.

Manual Gas Changeover Valves

With manual changeover valves, you need to manually reset the valve when the first bottle is empty. The changeover valve has a lever which must be set to point to the gas bottle in use is connected to the gas regulator.

gas bottle changeover valveTo use a manual changeover valve, you follow these three steps:
1. Turn the empty gas bottle valve clockwise to CLOSE the valve.
2. Move the changeover valve lever to point towards the second gas bottle, which will hopefully be full if the previous resident ordered gas when they should have.  If not, just give us a call.
3. OPEN the valve on the full gas bottle by turning it anti-clockwise.

Gas Fitting Supplies

If you need gas fitting supplies in Australia or New Zealand, we recommend Gameco. They have gas regulators, gas fitting supplies warehouse facilities in Sydney, Brisbane, Melbourne and Wellington NZ.

Remember to Order Your Gas Bottle

Don’t forget to order a replacement gas bottle when you switch over between bottles.  
If you do it right after the first one runs out, you should never run out of gas.
Learn more about LPG facts & technology


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The information in this article is derived from various sources and is believed to be correct at the time of publication. However, the information may not be error free & may not be applicable in all circumstances.