Selecting the proper delivery pressure range of a gas regulator is critical to choosing the right regulator for a particular application. The particular gas and gas service for which the regulator is to be used for are of vital importance when choosing the right regulator, but too often not enough attention is given to its delivery pressure range.
Regulators chosen with too high of a delivery range can actually be hazardous to use. It's easy to understand that too much pressure can cause problems and become a safety issue. Even though it does not present a hazard, too much pressure can damage other associated equipment and it can negatively affect the job or application for which it was intended.
Too little pressure for the application can also present problems. Quite often, for example, damage caused by flashbacks in oxy-fuel torch equipment can be blamed on improperly selected gas control equipment. Gas control equipment that cannot meet the performance specified by the manufacturer of the oxy-fuel equipment should never be used or recommended.
To determine the specified range, check with the original manufacturer or the distributor of the equipment whenever possible. If, for some reason, factory information is not available, consider this rule of thumb: select the delivery pressure range so that for the given application, the regulator delivers within the middle 2/3 of the regulator's rated delivery range under flow or dynamic conditions. For example: a regulator rated for 0-100 psig delivery is generally best suited for applications requiring 33 to 66 psig under flowing conditions. One rated for 15 psig delivery is best suited for applications requiring 5 to 10 psig.
By using this rule of thumb you should have just the right amount of pressure and never too much pressure potential nor too little.