NZ Home LPG Gas Regulators & Fittings
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. However, the required appliance inlet pressure for New Zealand LPG gas appliances is typically only 2.75kPa. So, a regulator is required to reduce the pressure and ensure a consistent 2.75kPa is safely delivered from the gas bottle to your appliances.
Regulators: Although the purpose of LPG regulators is the same, different applications may require different types of regulators. The gas demand of the appliances determines what type of regulator is installed. For example, if the combined megajoule (Mj) rating of your home’s appliances is quite high, a regulator with a higher Mj rating would be required. The regulator shown (right) includes an automatic changeover valve. Commercial sized regulators are completely different and frequently comprised of two separate units. Also, please note that under no circumstances should a BBQ regulator ever be used on a home installation.
How do regulators work? Regulators have a diaphragm, which is a flexible rubber disc that responds to pressure changes and functions to regulate the flow of gas to the proper pressure. The diaphragm works in combination with springs and other parts within the regulator. It also works in conjunction with the regulator vent which allows the diaphragm to move freely. If the vent is obstructed, the diaphragm will not operate properly. The vent should remain free of dirt and debris to ensure the regulator operates correctly.
Pigtails: The gas bottles are connected by tubing, known as “pigtails”, to a changeover valve and the changeover valve is connected to the 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. Also, pigtails can catch or trap debris over time so they should be replaced any time the 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 regulator connection, the piping would be rigid and more susceptible to leaks caused by movement.
Changeover Valves: 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. As the names imply, manual changeover valves require manual intervention while automatic changeover valves automatically switch between gas bottles when the first bottle runs dry.
Bayonet Connections: If you have a portable gas heater, it will be be connected to your home LPG supplied using a bayonet connections. Bayonet connectors can be floor or wall mounted. The male connector is on the end of the heater hose and plugs into fixed female connector which is, in turn, connected to the LPG service piping.
Service Piping: A gas line runs from the regulator to your appliances. This gas line is the service piping. It generally consists of copper tubing or flexible composite piping. The service 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: Please remember that all gas installations must be carried out by a licensed gas fitter.
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