This article explains LP Gas Pressure Regulators used on LP Gas or Propane tanks.
How to Inspect & Test LP Gas Valves Regulators, or Gas Controls and we provide descriptions and photographs of unsafe LP gas piping, LP gas regulators, or LP gas valves & controls on appliances or heating equipment.
We describe indications of unsafe or improperly operating gas appliances, gas meters, and other gas installation defects.
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If you smell gas you should leave the building immediately and should do so without doing anything that could create a spark such as operating a light switch or telephone. From a safe location, call your gas company's emergency line and/or your fire department. The text provided here is a working draft and may be incomplete or inaccurate.
If there is evidence of an LP or natural gas leak at a building, gas odors, for example, you should:
[Click to enlarge any image]
Above: a first (and only) stage LP gas regulator installed on a gas tank (gas cylinder) in New York. In a better installation the vent on this regulator would have been aimed downwards.
Because of varying requirements, LP gas regulator types found at a typical residential or light commercial property may vary using:
Other regulators less likely to be found at a residential property include:
Watch out: improper installation and even improper inspection and testing methods involving natural or "LP" gas can involve dangerous conditions and risk fire or explosion.
An LP gas cylinder regulator should be mounted so that any moisture or condensate inside the regulator can drain out. Any drain openings should be facing downwards.
Otherwise water or in freezing climates ice can accumulate and damage the regulator, forming an unsafe condition.
The photograph of an LP gas cylinder regulator above shows the regulator's vent opening.
In photo at above the red LP gas regulator can be seen installed in a tipped position in upper center of the photo.
The installer felt that the regulator would drain in this position, and that when the plastic cover was installed on the control well (this is a buried LP gas tank) the regulator would be protected from the weather.
The photograph at above left below shows at right the silver-colored LP gas tank on-off valve. An arrow on the valve will indicate the direction to turn the valve to close it or open it.
Normally you close the LP tank gas valve by turning it "clockwise" or as my daughter Mara says, "rightie-tightie, leftie-loosie" to help remember this important information.
The yellow cover on top of the valve is the connector for filling the LP gas tank.
The small-diameter copper tube leaving at the left side of the valve is the "high pressure" LP gas line carrying LP gas in vapor form from the top of the gas cylinder over to the LP gas regulator whose body you can just see in the upper left hand corner of this photo.)
Watch out: in addition to a gas supply shut off valve at the LP or propane gas cylinder or tank (or at the building gas main where piped-in natural gas is supplied), additional gas supply shutoff valves are required in the gas piping system at each gas-fired heating device or appliance.
See GAS SHUTOFF VALVES.
An LP gas tank or cylinder regulator should be protected from the weather. Water, particularly in freezing climates, can enter and block the safety vent on the gas regulator or ice can form preventing the regulator from properly controlling gas pressure. An iced or water-damaged gas regulator is unsafe.
Our photos above and below show how an existing LP gas tank regulator was protected from rain and weather by a simple rubber cover affixed to the building. The protective cover was secured to the building wall and draped over the regulator. Despite formation of ice and icicles at the roof eaves and even atop the propane tank, the LP gas cylinder regulator was dry and functioning safely.
This option (adding a protective cover for the gas cylinder regulator) was elected when a new LP gas tank (shown in this photo) was installed and connected to an existing regulator difficult to relocate. Below: Bottini fuel delivering LP gas to this home in winter.
Watch out: It is important that any cover protecting an LP gas regulator does not block fresh air flow around the regulator. Otherwise leaking LP gas can accumulate and form an explosion or fire hazard.
Gas pressure too high:
Adjustment of a gas regulator might also be necessary if the gas piping from source (meter or tank) to the appliance is long or is too small in diameter.
If the gas regulator delivers gas at too high a pressure the gas flame may be also too big (and too hot), which can accelerate
rusting and can warp the heat exchanger at its lower joints causing a "crack" to appear.
A cracked heat exchanger on a gas appliance is unsafe.
Our correspondent, Charles commented that:
After loosing three heat exchangers in two different homes that had routine maintenance inspections, I decided to look into it and check the gas regulator pressure myself. The same problem can occur with gas water heaters.
Gas pressure too low: if the gas regulator is not properly adjusted or if there are other problems in the gas piping or supply system the gas pressure may be too low, providing an inadequate and possibly unsafe flame.
Depending on the cause of the problem, it may be possible to correct this at the regulator, but don't try boosting pressure at a gas regulator unless the pressure has always been too low. Otherwise when the underlying cause for low gas pressure is corrected elsewhere, the flame will be too big and pressure too high at the burner - an unsafe condition.
Watch out: SAFETY WARNING: If you lack the training and equipment, do not attempt to disassemble or mess with a gas regulator as you could create a very dangerous or even fatal problem.
Details about the different pressures found or set for LP gas, propane, and natural gas including before and after different gas pressure regulators are
at GAS PRESSURES LP vs NATURAL GAS
Continue reading at GAS REGLATORS, TWO STAGE or select a topic from closely-related articles below, or see our complete INDEX to RELATED ARTICLES below.
Or see GAS REGULATORS for APPLIANCES - installing, inspecting, or testing LP or Natural Gas regulators which are found on appliances such as LP or Natural Gas fired boilers, furnaces, water heaters or appliances
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(Aug 29, 2011) Jeff said:
I have a propane tank that feeds my standby generator. I am interested in adding a propane range to my house (about 200' away). I have buried black plastic piping between the two locations. Can I run a high pressure line to the house, install a regulator there, then low pressure to the range? Does the regulator need to be outdoors? The black plastic comes into my basement, but I could run the HP line through the sill back outside for the regulator if required.
Jeff, yes; you'll need to comply with local codes and the National Fuel Gas code to be safe. Be sure that the buried line and all other sections of piping are of approved material and are protected from damage; and yes you will want a second LP gas regulator at the house as well as the regulator at the appliance. Otherwise you may find that there is too much of a pressure drop.
(Sept 9, 2012) Ken Wayne said:
The new Ho Chi Minh City, Vietnam apartment building I moved into supplies SUNHOME two burner LPG from a tank underneath the counter. My first try at boiling noodles, the burner (set to medium low, soon explodes with flame powerful enough to blow the pot across the room and then dresses me down with flame all the way down to the floor. I was wearing shorts. Sans leg hair and some arm hair I incur 1st degree burns from front of thigh down. SHELL tank, SHELL model #2010 (KABSONS India company made) flow regulator with "Excess Flow Safety". (EN:12864 NOM. OUTLET Pr. 30 mbar Max INLET. Pr. 16 BAR) Capacity 1.5kg/h So, get it tested before I pursue my options of compensation?
Certainly you want an expert inspection of the current installation for safety and you should expect the inspection to specify the actual repairs needed. It sounds as if your system may have had an LP gas leak or uses the wrong orifice (natural gas for example) or the wrong pressure settings. As your note cites, all of these are very dangerous conditions.
(Mar 8, 2013) Anonymous said:
is it wise to install a standby generator and us the existing supply line regulator?
Plumbing codes permit multiple appliances to be served from a single gas line provided piping and shutoffs are installed to code. If you are asking about natural gas, if in your area that supply is often lost during storms ot other disasters that sounds sensible too.
Keep in mind that in flood zones if your LP tank floats up ie was not anchored, the piping will be disturbed and unsafe.
Also there maybe additional clerance distance specifications beween the LPG tank and the generator.
While our local propane company was installing a new tank, the valve failed and the entire contents of recently filled 100 lb tank were spewed into the air at high speed, causing an explosion (but not a fire) which resulted in a temporary loss of hearing for my 69 year old husband and the propane delivery man. Rather than replace the valve, they "rigged" the system and said it could be fixed after we empty the tank. I am concerned about the long term effects on my husbands health, our lawn and landscaping, the nearby hardiboard siding and our roof (not to mention our neighbors and the environment).
I am also concerned about our safety due to the temporary fix. I can't find any info this type of incident over the internet. My husband thinks it is no big deal and refuses to contact anyone or notify our insurance carrier. Over the cell phone, I heard my husband's conversation with the propane expert who came out to inspect things, so I know my husband was not exaggerating. Should I be concerned about this incident, or am I just a nagging wife?
I can't offer very specific advice as we're just relying on information in an e-text but it sounds scary to me as well - as if amateurs may have jury-rigged an important safety control on your LP gas system. But then I'm not clear just what failed - the tank fill valve or the gas regulator valve.
In my OPINION, an LP tank installer who is putting in a new tank ought to know what they're doing. If they don't I'd first call the company's service manager and ask for an experienced qualified installer to do the work.
Meanwhile what to do now? I'd give your local plumbing inspector and fire department a call to
- check for safe and proper installation of all of the LP system components
- check that there are no gas leaks.
If you can provide details of what your "propane expert" saw and said we might be able to research and comment further. I'm having trouble reconciling the events you escribed with an inspection by an expert whose comments and findings are not in your note. Also you can use our CONTACT link at page top or bottom to send us photos of what's installed at the present - allowing further comment.
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