Elgas LPG Gas Blog

Gas Regulator: LPG Gas Regulator, Regulator Gas Pressure, Gas Bottle Regulator & Gas Bottle Fittings

The primary function of an LPG gas regulator is to reduce the temperature dependent LPG gas bottle pressure from 400-1200kPa down to the required 2.75kPa operating pressure for the gas appliances. Gas bottle pressure varies with temperature but the LPG gas regulator must be able to consistently maintain 2.75kPa.

Gas regulator types include an LPG gas regulator, acetylene gas bottle regulator, oxygen gas bottle regulator plus all of the gas bottle fittings, gas bayonet fitting, pol gas fitting and gas regulator fittings that are the gas fitting supplies for welding or an LPG gas installation.

A gas regulator reduces the high pressure from the gas bottle to a consistent regulator gas pressure, as required by the application. Gas regulators are used for all compressed gases and gases liquefied under pressure, like LPG gas regulators for LPG bottles.

LPG Gas Regulator - Gas Bottle Regulator - Gas Regulators for LPG Bottles

LPG Regulator for LPG Gas Bottles - Propane Regulator

The principal task of an LPG gas regulator is to reduce the temperature dependent LPG gas bottle pressure down to the required 2.75kPa operating pressure for the gas appliances. Gas bottle pressure varies with temperature but the LPG gas regulator must be able to consistently maintain the required pressure.

LPG enters the regulator through the inlet port and the pressure is controlled by a factory pre-set spring loaded diaphragm, so no needle valve required. The diaphragm moves with pressure changes and adjust the inlet valve accordingly.

An LPG gas regulator works to make an automatic gas regulator adjustment, reducing high pressure gas to the required 2.75 kPa gas regulator gas pressure for LPG appliances or equipment.

Gas regulators for LPG bottles are an essential part of an LPG system, as without an LPG gas regulator reducing the gas pressure, the LPG would be unsafe to use.

The pressure within an LPG gas bottle can be 400-1200 kPa vs the 2.75 kPa LPG gas regulator gas pressure typically required by LPG gas appliances. The gas bottle regulator (gas regulators for LPG bottles) gas flow output reduces this and is required with all LPG gas installation.

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

LPG gas regulator gas pressure is usually factory pre-set to make the automatic gas bottle regulator adjustment to achieve the standard operating pressure for gas appliances.

LPG gas regulator (gas regulators for LPG bottles) is sometimes referred to as cooking gas regulator, when used with cooking gas appliances.

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

Regulator Gas Pressure

Regulator gas pressure is controlled by spring loaded, diaphragm controlled balanced gas regulators. Low, medium and high pressure can all be accommodated by a gas regulator. Gas pressure regulators are adjustable with balanced diaphragms.

These adjustable regulator gas pressure versions include 150 kPa acetylene gas regulators, 800 kPa oxygen gas regulators, 150 kPa argon gas regulators, 50 psi nitrogen gas regulators and 150 psi helium gas regulators, as well as others.

Regulator gas pressure can be factory pre-set, as is the case with an LPG gas regulator at 2.75 kPa. Regulator gas pressure for other gases have a factory pre-set maximum but are adjustable downward, to reduce the working pressure.

The adjustable gas regulators have two circular dial pressure gauges and an adjusting knob.

One gauge indicates the pressure in the cylinder (incoming pressure) and the other gauge indicates the regulator gas pressure of the gas coming out (outlet pressure). The adjusting knob must be opened before any outlet pressure is shown on the gauge.

This outlet pressure is the working pressure that is set by the user for the particular application.  

These gas regulators come in single stage and dual stage models. Dual stage are better at maintaing a constant regulator gas pressure but they are also more expensive to purchase.

How Does a Gas Regulator Work - What Does a Gas Regulator Do: Gas Regulator Operation

An gas regulator works to automatically reduce high pressure gas in the gas cylinder to the required lower gas pressure for the appliances or equipment. A gas regulator does this with a rubber diaphagm and spings that work to make an automatic gas regulator adjustment within the gas regulator, to modulate the regulator gas pressure.

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

Gas regulator operation does work in conjunction with the gas regulator gas pressure vent, which operates to allow the gas regulator diaphragm to work freely.

If the gas regulator vent is obstructed, the gas regulator gas pressure operation does not work properly and will be impaired. 

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

Gas Regulator Problems - Propane Tank Regulator Problems

Gas regulator problems (propane tank gas regulator problems) can occur as a gas regulator gets older. The gas hose can crack and perish from old age.  The same is true of the rubber diaphragm.

Gas regulator problems (propane tank gas regulator problems) also include a blocked vent, as the gas regulator diaphragm works in conjunction with the gas regulator gas pressure vent, which allows the diaphragm to move freely.

If the gas regulator vent is obstructed, the diaphragm will not operate properly to make the required gas regulator adjustment. You should use care to make sure it remains free of dirt and debris, to help avoid gas regulator problems (propane tank gas regulator problems).

Gas Bottle Fittings, Gas Regulator, POL Fitting & Gas Appliances

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

The gas regulator gas flow comes from the changeover valve, which determines from which gas bottle the gas is being taken.

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

BBQ Gas Bottle Fittings with POL Fitting

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

Camper valve adapters may also be required for POL fittings or 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. 

Gas Regulator Gas Bottle Pressure vs Appliance Pressure

The appliance inlet pressure for Australian LPG gas appliances typically requires 2.75kPa gas regulator gas pressure. So, a gas regulator gas pressure flow is required to be reduced and ensure a consistent 2.75kPa gas regulator gas pressure is safely delivered from the gas bottle to your appliances via the gas bottle fittings.

Gas regulators for LPG bottles are an essential part of an LPG system, as without LPG gas regulators reducing the gas regulator gas 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 to the required 2.75kPa gas regulator gas pressure.

LPG regulator

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

Gas Bottle Regulator Types & Sizes

Gas bottle gas regulator types & 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 gas regulator types and sizes.

The gas demand of the appliances determines what gas bottle gas regulator type, gas bottle fittings and size 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 gas regulator units and gas bottle fittings.

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

Gas Bottle Gas Regulator Types - Gas Regulator Adjustment Controls

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

There are different gas bottle gas regulator types and  gas bottle fittings based on the application operation. Gas regulator types are rated for flow rate, with different size gas regulators for operating with 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 gas bottle fittings piping between the gas bottles and the application.

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

Gas Regulator for Gas Grill Propane Tank - BBQ Gas Bottle Regulator

A gas regulator for gas grill propane tank (BBQ gas bottle gas regulator) is a small gas regulator that typically incorporates a gas hose. A gas regulator for gas grill propane tank (BBQ gas bottle gas regulator) typically screws directly into the POL fitting of the gas grill propane tank or BBQ gas bottle.

In Australia, the gas regulator screws into a POL fitting connection.

Remove Gas Regulator from Gas Bottle - Propane Tank

If your BBQ bottle (propane tank) is empty, just follow these simple steps to remove gas regulator from gas bottle:

1.  Make sure the Gas Valve Hand Wheel is turned OFF (Clockwise)

2.  To remove gas regulator from propane tank valve, start by turning the Gas Regulator Hand Wheel clockwise (reverse thread).  

Be aware and careful, as a small amount of gas remaining in the gas regulator and hose may be released when you remove the gas regulator.

3.  Remove BBQ gas bottle (propane tank) from BBQ grill by lifting the empty bottle off of the mounting hook or out of its holder/shelf, depending of your BBQ grill. 

NOTE: These How to Remove Gas Regulator from Gas Cylinder instructions only apply to gas bottles with POL fittings

Gas Pigtails POL Fitting

copper pigtail for LPG installation

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

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

Copper is generally considered the best choice for gas bottle fittings, 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" gas bottle fittings 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 gas bottle fittings, 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 gas bottle fittings 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 ordered when it should have.  If not, just give us a call.
3. OPEN the valve on the full gas bottle by turning it anti-clockwise.

Gas Bottle Fitting Supplies

If you need gas bottle fitting supplies in Australia or New Zealand, we recommend Gameco. They have gas regulators, gas bottle 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.