LP. Gas Systems

[david craft]

All RVs should have 2 stage LP regulators. The regulator should be in a fixed position with the vent facing down or within 45 degrees of down. If you have a single stage, change it please. The old style LP fitting that threads into the service valve(on/off) should be replaced with a "excess flow" POL. This will restrict the flow of the propane in then event of a major leak in the system. These are reverse thread on internal threaded valves and right hand thread on the external threaded valves. It should be said as well that forged flare nuts should replace all the "milled" nuts on the lines...especially on old lines where the nuts will split right down the side with little provocation. Back in the day, it was common to use a tubing bender to get that nice tight radius. But, when the tubing ages and added road vibration occurs, this results in splits occurring in this area as well. Large "vibration" loops are the norm now. It also makes lines easier to connect. I have to admit, old LP appliances make me nervous. But there are some things that can be done to make things safer. LP leak detectors are a good place to start. Use OPD style LP tanks. There are universal style gas controls that could and should be retrofitted to older appliances if you want that old appliance retained. Check for leaks with a thick soap solution sprayed or dabbed that doesn't contain ammonia. I'll close with backyard LP leak test. First, bleed stale LP gas from system so fresh gas is in the manifold. Turn off all valves and pilots. Turn off supply valve on tank. Wait overnight. Turn on range burner and light burner. It should light briefly and go out. If it doesn't light, you have a leak. If it continues to burn, you have a leaky supply valve and the test is invalid. Images of regulators(one and two stage) and flare nuts(milled and forged) can be found by google. I hope this helps someone. Happy RVing and be safe...

[david craft]

second wind...in terms of short flexible line:
1. I dont want any thing with rubber near an appliance.
2. Those accordian looking brass lines used in home appliance connections are made to accomodate movement of appliances for disconnect and reconnect. I've never seen them proven in the RV environment.
3. Copper has proven itself over time. Milled nuts and tight radii are the weak links. I would not go tighter than a 12" diameter loop or a 6" radius in any bend. Thats assuming a 3/8" line. Larger radii for larger line. I don't fool with 1/2" much. The line will tell you what feels right. A comfortable bend by hand with no fear of kinking.

Speaking of Youtube videos....any educational video concerning LP tanks, connection, regulation, manifolds ect..for any RV application that does not jibe with the information contained in this blog should be checked for sound sourcing.

This site is the sole location for any posting of this kind from me. It is my wish that this get "stickied" or even edited with the approval of the web master into a concise thorough treatise on the subject. I plan on sending all those with LP questions HERE...to this site. I personally have not searched the other "how to" sites. Ive heard rvers corner is good. I do not know what he has on the subject. This site seemed appropriate...those who are working on these old coaches seemed like they would benefit the most. I personnally admire what you do here. You even got lawyers giving free advice here...am I in heaven?? Sorry John...could not resist that one. The new coaches will not last like the old ones do. You guys are like rebels in a throw away society...I get it. Or do you just harken back to better times? Is it retro look? All the above I imagine...Carry on

[david craft]

I guess I should clarify a few things...
1.ASME tanks dont need requalifying.
2.DOT tanks do need requalifying.
3.I dont recommend flaring or splicing old copper...it usually splits
4.I do recommend replacing the line entirely from the black pipe to the appliance if it has milled nuts and is over 20 years old. Severe duty(i.e.off road etc...)probably should be replaced sooner.
5.ACME tank fill valves (1 3/4" acme thread) shouldmbe replaced if they dont seat after filling. The filling attendant should bleed the chamber between the fill valve and his shutoff valve completely before removing the fill hose. If it wont bleed, then he should repressurize the chamber and tap the fitting on the side where it connects to the fill valve and bleed again till it seats properly. Tapping the plunger can cause it to freeze in the open position and dump HUGE amounts of propane in a hurry. 83 and earlier coaches have a standard fill valve with no overfill protection. I SERIOUSLY recommend watching whoever fills these tanks for you to see that they:
a: Fill using the 10% valve. This is the small bleed screw that is cracked open during filling. When the tank is full the bleed screw will seep liquid propane. This indicates that the tank is full and it is time to stop filling. Some filling attendants assume you have an "autostop" fill valve and just run the pump till it goes into bypass...This is wrong and dangerous. Now you got liquid going to your regulator which is one reason you need a 2 stage reg.
b. bleed all the pressure down from the fill chamber before removing the fill line from the tank. So in the event the fill valve does not seat, he can repressurize and try again.

[Rich Thomas]

Thanks again David, all any body needs to do is look at You Tube for camper fires to see where your coming from. I'll follow your advice! ..........Rich

[John "T" Nordhoff]

  David Craft,

  Thanks for the info about an RV tank NOT needing re qualified, I wasnt aware of that. HOWEVER as noted be sure to keep them rust free and epoxy painted or coated if necessary.

 QUESTION I've had a few that after a refill they didn't reseal complete until a brass punch etc was inserted and tapped which momentarily depresses the valve/spring and then they sealed back fine BUT I DONT LIKE THAT !!!!!!!!!!! My current one has never done that but if so Id say its time for a new Marshall fill valve etc.

 What are your thoughts on using a short link of flexible line to hook up an appliance in lieu of a vibration loop in the soft copper??? I say its more connections to worry about and Im NOT a fan of such, but if the loop isn't already there and you want to add more copper for a loop that's still another connection grrrrrrrrr

 If I ever have an LP Gas question Im seeking  you out.

 John T

[david craft]

We all just jump in here and I invited comments somewhere in this blog I believe. Anyways, I feel we all have something to learn and to share. I'm new here and have posted a lot. I'm still figuring things out. The nose is an excellent tool for LP detection. Young better than old...womans better than a mans I've found. It will detect a leak you cannot reach with leak fluid. Propane is only explosive volumetrically in a 4 to 11 percent ratio to air. More or less you just get fire. Do that leak test I explained earlier on a regular basis...maybe before each trip if you dont go often. Carry a fire extinguisher. The failures I described ealier in the manifold can result in a serious leak in a brief incident.

[Rich Thomas]

Thanks for the info David. I don't know why my comments/question went to John "T" Nordoff  or some how when I commented I hit the wrong button. I was commenting on your blog. but I'm thankful for yours and his thoughts. I do understand  your theory on the aged copper and believe me I am well aware of the age thing. I graduated high school just 4 yrs. before my camper was made. went to work in the coal mines at nineteen, 2 years before it was made and my pipes are a bit rough too. sorry about the confusion between my terminology too as an electrician we called for a DROP LOOP for strain relief and sometimes that stuff just carries over. I am impressed with your knowledge on the subject and think it amazing the amount of talent on this forum and how people share it freely and openly. I will follow your advice as time goes forward. I do think I'm ok in the short run as the techs at my local RV Dealer did pressure and soap test prior to me using any of the appliances and I made sure they changed the regulator (I've been down that road before). I think your advice is spot on and it is not wasted on me thank you again.  

[david craft]

Hey John...can I get a link to that Good Ol Litigation site... I may need some advice someday...lol

[david craft]

Hmmm...all the stuff I left out...
1. ASME tanks(the lay down horizontal style tank, fittings in side generally) are found on the motorhomes. They are to be secured to the coach now instead of the chassis. In theory if the coach separates from the chassis it goes with the coach. Copper is required throughout the coach to be 50 state legal except for the tank to manifold connection. BTW this hose has a tendency to collect oil from propane through the years and should be drained periodically. These tanks are thicker than the DOT tanks (vertical, found on trailers, fittings in end generally) and do not need to be requalified, though a wire brush and paint are in order. How thich is the tank? Its the same thickness as the guard...much thicker on the ASME.
2. DOT tanks, found on trailers and BBQs, are good for the first 12 years, then need requalifing ever 5 years. All tanks 4 to 40 pound(1 to 10 gallon) need OPD valves EXCEPT the lay down horizontal DOT tanks found primarily in campers...they were exempted contrary to popular belief.
3. Any place where there is a tight radius to make a 90, just run past the bend and do a 270. Say a line protrudes through the refrigerator support shelf and bends a tight 90 to the connection. Just replace the entire line and do a loop behind the refer then make the connection. Use the forged nuts now available and I personally double flare. I don't know of any laws that state how old an LP system can be before it needs replacement. But lets be logical for a minute. That copper that is on the coach was as soft as the new stuff when it was installed close to 40 years ago on that 78...yes its been that long. It has oxidized and now is stiff and brittle. I think the black 1/2" manifold pipe could be left if it shows no abuse and maybe the brass fittings since they are thick and tough and prolly better than whats made today if they were not overtightened. But, Ive seen many a milled flare nut split and those tight radiused copper lines split as well. Ive already voiced my opinion on appliances. I know that prolly went over like a flock of dogs but I just want peeps safe...
4. Service valve: If it passes the soap test at the handle its ok. Its good if they dont leak when partially open...so you can close them in an emergency. Its a double stop valve so if they do leak that way...you can open them all the way and get them to quit leaking in an emergency...but I'm NOT advising that...

[John "T" Nordhoff]

  Rich Thomas, the BLOG was from David Craft I believe, but until he arrives I will throw my two cents worth into the mix:

 1) The purpose of ant vibration (not drip) loops is to allow flexing and expansion and contraction between the RV frame and the coach body or appliance which the line serves. Sure, a length of flexible braided hose can accomplish the same task (if in the right location where flexing may occur), but that's just two more connections to worry with or that have an opportunity to go bad or leak. Its much simpler when running that soft flexible copper to coil it prior to hook up. But if it wasn't done originally you're still going to need a splice and coupler to make a loop so a piece of flexible may be easier???

 2) Sure, in theory every x number of years those tanks should be pressure tested and re certified, especially due to rust salt and corrosion, but I bet there are a gazillion out there (maybe my own!!!) that never are!!!!!!!!!!!  

 3) Its not hard or too expensive to install a new regulator and valve as years pass and I would advise that.

 4) Do some leak down checks and the soap checks and if all is well and you have a good detector you are probably in okay shape, but its always best to hire an RV or LP Gas professional to check it. (Had to say that since I'm a lawyer lol)

 SEE WHAT DAVID HAS TO SAY, THIS IS HIS BLOG NOT MINE

 John T

[Rich Thomas]

Reading your blog has enlightened me to some potential problems I don't need! I purchased a 78 TravelCraft Back a month or so ago. the very first thing I done was new tires, the next was a full inspection of the gas system. I had them change the regulator at that time and all was given a clean bill of health. My concern now after reading your blog is the lack of drop loops in the lines for the appliances. I don't want to fix whats not broken but was thinking maybe I could lesson the risk by adding a braided line at each appliance and hard fasten the copper to the chassis( your opinion welcome here), also I was wondering about the tank its self. Does it need pulled and re-certified like Oxy/Acct. tanks. I plan on keeping this camper in top shape and using it often but I'm hoping to maintain the current appliances for as long as they work. The old girl just appeals to me for some reason. The tank valve was also something i was planning on having changed but I felt I should use up the propane that was left in it first. I bought a new Atwood propane leak / carbon detector but as yet not installed it but it is on the short list . Any advice you care to advance will be appreciated.......Rich