This information is for informative purposes only. All LP Gas installations must be performed only by qualified installers in accordance with all applicable codes and industry standards.
LP Propane Gas Regulators Explained
The main function of the propane regulator is to control the flow of the gas output from the propane tank to the appliance being fueled. A properly performing propane tank must maintain a steady gas flow even with varying pounds per square inch gauge, PSIG (the pressure inside the tank). The tank must be able to accommodate varying pressures from 8 PSIG to 220 PSIG without interrupting the gas flow at 11 inches of water column (w.c), which is required by the appliance.
To help in this operation is the two-stage regulation. Let’s take a look at this and see how it works for better understanding:
Two Stage Regulation
This propane regulator received its name because of its role. Installation of a two stage regulator will provide uniform pressure to appliances. Understanding that there are varying pressures caused from inside and outside the tank, this propane regulator is a two-stage system that contains:
- a high-pressure regulator at the site of the tank to compensate for varied inlet pressure
- a low-pressure regulator at the site of the building to maintain constant pressure to the appliance
This regulation device keeps the pressure within 1 inch of w.c. even with varying outdoor temperatures and conditions that affect the pressure
Reduces Frozen Nozzles
The reason why the nozzle would freeze is due to moisture getting into the apparatus and freezing, thus making the function of the propane tank difficult or impossible. The freeze will occur when the tank is under high pressure allowing the gas to expand into the body of the regulator.
As the two-stage regulator does its job to maintain the constant pressure inside the propane tank, it also eliminates freezes from occurring. This will save the owner time and money as it also eliminates service calls to fix the issue.
How it works is there is less chilling at the site of each of the two regulators, and as the gas exits the first-stage regulator and goes into the first-stage transmission line, it will be warmed up with the heat it provides eliminating the chance of freezing any moisture in the second-stage.
Two-Stage Regulation Installation Facts
Please consider your transmission line piping which connects your propane tank to the appliance, to make sure that it is the correct size to efficiently and effectively accommodate the required volume of gas at 11 inches w.c.
Looking at the piping from the first-stage regulator to the second-stage regulator in this two-stage system, this can be a smaller pipe as it only delivers a PSIG of 10. The good news about this is that the savings from getting a smaller pipe for this connection can help fund the second regulator.
Where Extreme Cold Temperatures are a Factor
Being wary of the condition of the first stage regulator is very important if you experience cold winter temperatures. Watch this regulator for any propane vapors that might be turning back into liquid which poses a threat of freezing and locking up the system.
To further illustrate, temperatures reach as low as -20ºF, the first-stage regulator should not be set higher than 10 PSIG. If temperatures reach as low as -35ºF, the setting of the first-stage regulator should not be higher than 5 PSIG.
More Appliances are Welcome
Another benefit of the two-stage regulation system is that if the owner would like to add more appliances to the system via another low-pressure regulator, the two-stage system can accommodate at the present load as long as the high-pressure regulator can manage the increase.
Each appliance is regulated independently thus installing other appliances should not affect the system’s performance.
Regulations on Single-Stage Regulators:
Please note, according to the National Fire Protection Association (NFPA 58 1998), it is prohibited to install single-stage regulators in any fixed piping system. Such systems include appliances for RV’s, motor homes, food trucks, and manufactured homes. Twin-stage or two-stage regulators are the only regulators that are mandated on these appliances.
For the convenience of the owner of single-stage regulators, these systems can be easily converted to two-stage systems using existing supply lines when they are unable to meet the required load.
Small outdoor cooking appliances with an input rating of 100,000 BTU/hr or less are permitted to use the single-stage regulator.