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MHUniversity Glossary

Here is a general glossary to help you navigate the wonderful world of heaters and propane.

Standard Abbreviations


The British Thermal Unit is the amount of heat required to raise the temperature of 1 pound (0.4kg) of water 1°F


Liquid Propane is a compressed gas found in canisters ranging from 1 pound to 100 pounds plus, the most common being 20 pounds


Canadian Standards Association


Stands for Overflow Protection Device that is located INSIDE refillable propane tanks up to 40lbs. 


National Pipe Threads - an American standard thread


(Presto-lite) Adapter is a commonly employed thread (L.H.) connection used for propane cylinders; meets the specifications of the American Standards Institute



Also called Flashback.  The flash back of the flame through the venturi (the burner and tube feeding the burner) causing burning at the orifice.


Device forming an integral unit for the introduction of propane with air or oxygen into the combustion zone for ignition.


With respect to propane storage refers to a container designed and fabricated in accordance with the specifications of the US Department of Transportation for the storage of propane.

L.H. Thread

A threaded connection where the male thread is turned in a counter clockwise direction into a female thread (L.H. – left hand)


The opening in a burner or other device whereby the flow of propane gas is limited and through which the gas is discharged to the burner.

Liquid Propane

A hydrocarbon product (HD5); A special grade of liquefied petroleum gas composed of a minimum 90% liquid volume of propane (C3H8) and a maximum of 5% liquid volume of Propylene (C3H5) – Ref. ANSI Z21.57, ANSI 283.6, Z83.7

R.H. Thread

A threaded connection where the male thread is turned in a clockwise direction into female thread (R.H. – right hand)


BTU input burned by an appliance during one hour of full operation.


A device for controlling or maintaining a uniform gas pressure.

Safety Shut-off Valve

A device that will shut off gas supply to the controlled burner in the event of flame failure.

Soft Nose

With fitting refers to a P.O.L. with a rubber “O” ring that acts as a secondary seal for connection to a propane cylinder valve.

Tank Union

A P.O.L. assembly with a R.H. female device – i.e. the valve on an appliance.


The pair of dissimilar metallic elements so joined as to produce a current when the junctions are at different temperatures.  Used for sensing the flame in a safety shut-off assembly.