Regulator Orientation – Why it Matters
- Post By: Greg Crumpton
- Date:
- Category: Blog
The inclement weather we recently endured here in the South got me thinking about a technical topic that I wanted to expand upon.
We have a very robust network of natural gas service from local utility companies here in our region, so naturally we have an abundance of gas fired heating equipment to complement the services available. To minimize the size of the piping that has to be run to each piece of equipment, many times the utility will provide a 2 PSI (pounds per square inch) supply of gas to the leaving side of the gas meter and therefore to your specific equipment. The equipment itself is not rated to handle 2 PSI of pressure, so the installation of a small regulator is required in order to reduce the gas pressure to a one that the system can handle. This pressure is not measured in PSI, but instead is measured on a much smaller scale called, Inches of Water Column. This is a more precise measurement of lower pressure and lower flow mediums, such as the flow of natural gas into your heating gear. The proper setting for the regulators would be 2 PSI input with 3.5″ W.C. output to the gas train of the unit. This is an adjustable device, made to compensate for the variances in what the local utility provides, approximately 2 psi, so you can tweak it for the proper output in case they actually deliver 2.4 psi or 1.75 psi, etc.
OK, enough about the science of regulators, the problem with them is not the functionality or the setting, it is typically in the actual installation and the orientation of the “vent tube” and the prevailing winds at the site of the installation. The regulator works by allowing a diaphragm to “float” up and down to maintain the proper output pressure, again around 3.5″ W.C., regardless of the operating status of the gas consuming appliances (furnace, boiler, RTU, stove, etc…), whether it’s on or off.
The freezing rain and snow can wreak havoc on this diaphragm by having moisture freeze on the surface of the neoprene (or similar material) diaphragm itself. Once this moisture turns to ice, the regulator gets “stuck” and can’t regulate the outlet pressure; this causes the heating gear not to heat. It will have the same symptoms as if the gas was turned off.
So what causes this moisture to get into the regulator to begin with? The liquid can enter the regulator through the vent opening. This vent is the common measurement (atmospheric pressure) that the regulator uses as its internal barometer. If the vent opening is positioned incorrectly rain can drip into the body of the regulator, blowing rain from prevailing winds can also cause moisture to get into the regulator. You can solve this by extending the vent tube to face downward, either with pipe fittings or copper tubing of the proper size with the proper fittings. There can be other reasons for the moisture. Perhaps last winter the regulator froze due to one of the conditions above and cracked the cast aluminum body, now water is simply seeping into the regulator through the damage.
Here’s what to do if you find this condition:
Thaw the regulator and get it floating again; this can be done simply by heating the regulator body up with an external heat source, maybe a blow drier, heat gun or similar device. You can remove it from the piping and heat it up in the service van then blow it out thoroughly with Nitrogen. Once you have it functioning again the key is to prevent the ice from reforming. Be sure to rotate and/or reposition the regulator or extend the vent tubing or if required. If it’s cracked or leaking, replace it.
File this useful information away, it may save you, your customer or whomever you serve a cold day or night.
Stay warm and remember spring is coming!
