Read an article recently in either Family Motor Coaching, MotorHome, or Good Sams magazine about the qualifications of technicians that work on the propane system. Unfortunately, I can't put my hands on the article. But it said that the technician should be RVIAA certified, and have a manometer and some other testing tool at the very minimim. The article said that if the technician doesn't know what a manometer is, better find a different technician. Considering the potential for disaster in a propane system, what do you all think about this?

found this
http://www.motleyrvrepair.com/...e_safety_and_use.htm

and this
http://www.everything-about-rv...-amount-of-time.html

Good reference articles. Regular inspection is the key.

Propane systems are not rocket science but technicians today are often not impressive with their skills and knowledge, (or lack of) Training is probably good, experience even better.

A manometer is just a simple device to measure the very low pressures in the regulated gas lines, well under 1 psi. They better know what it is and how to use it!

The original ones were just glass u-tubes (about 2 ft tall) with water in the them. Hook one side to the gas tap on the device valve body, or in the supply line. The pressure pushes the water up one side of the tube. The difference in the two sides measures "inches of water" pressure. (Most techs now use very low pressure mechanical style gauges.)

For natural gas systems the pressure should be 4-5 "inches of water" and for propane about 11-13 inches difference in the water levels on each side of the u-tube. (Some devices like 2 stage furnaces run the low stage at something lower than the full amount.)

If the pressure is too low, the device will run less than the rated output. (In any case, the propane output is often lower than nat gas due to limits on the amount of air available for the propane setup)

If pressure is too high, the device may overheat, burn incompletely or otherwise malfunction.

The high pressure (tank side) will have about 150 psi depending on temp. 2 stage systems have the 1st regulator to drop the tank pressure to something lower (ie 30 psi) in the lines, then after the 2nd regulator it drops to inches.

Liquid systems for LP generators have different pressures and regulators but the general concept is similar.

Divers know that 33 ft of water (396 inches) is one atmosphere of pressure (14.7 psi at sea level)

soo.. 26.9 inches water = 1 psi and 1.0 inch water = .037 psi

In our propane systems, about 12 inches or .45 psi

Thank you, Jim and Professor Steve. I posted the motley article at my Pleasure-Way Class B forum.