LPgas line sizing

Unknown

a 3/8 semi rigid copper (ACR) at 10 PSIG and a 1.0 PSIG pressure drop at 50 feet will handle 215,000 BTU's.

If you went to K or L 3/8 will handle 443,000.

If you went to PE tubing with nominal outside diameter (CTS) at 50 feet 1/2" will handle 578,000 BTU's.

pinball_2

underground gas leak update and new question

Hey guys, well we found the leak (remember the previous post?) anyway it was a cracked black coupler due to frost heave. The question I have is since this is a two stage LP line, can I snake a 3/8 o.d. coated copper line through the leaking 1/2" black pipe? I have a total load of just under 200,000btu's The length from the 1st stage to the second stage is less than 50ft. It would make life a whole lot easier not to have to dig up a finished driveway.But is 3/8 big enough? 1/2" wont fit easy if at all.
Thanks Al

Weezbo

i dont recommend that approach.....

did you insulate the pipe underground?does it turn in any way underground? the option i see is take the ground cover off at the tank, and at the house connect 1/2" to the end of the black iron and pull the stuff through the space the black iron now occupies...when you get to the coupling you would have a choise to make,re make the couple and rethread and pull the blackiron back, or commit to the use of the material your chinese finger puller has a grip on..and drag it the rest of the way to the tank:) LP is like 1.6 times the X NAT GAS capacities....with me?

pinball_2

I'm not exactly with you weezbo, What I have is a 1/2" black pipe streched underground to traverse a driveway to the tank. It is straight with no turns. The bedrock is less than 12" below ground. We ran black, sleaved in PVC. (recomended by gas co.) the ground heaved and broke the pipe at a coupling. Since coated copper is ok under ground and I only needed protection from "crushing" I thought maybe I could leave the black pipe as is and run a new copper line through it. then I would have plastic coated copper, inside black pipe, inside PVC. i'm just not sure that I would get the btu's through a 3/8"od line @ 45 ft usuing two stages. understand?

Thanks for reply quickly I'm still here on Sunday!

Al

Weezbo

it would be better to remove the black iron leave the pvc

repair or replacethe black iron next option is to use 1/2"of another approved material fastened to the iron pipe when you make the "Pull" 3/8 ths isnt recommended by lp companies.they want to insure that the appliances actually see the flow rate and pressure at the regulator...i know what you are saying...

EBEBRATT-Ed

Table 12.25 NFPA #54- pipe sizing for LP gas. 3/8 OD copper between first stage (hi press. reg) and second stage (low pressure reg) with 10 psi inlet pressure 3/8 od will carry 215,000 btu/hr

Ed

Pinball

THANK YOU!

Thats what I was looking for. It will save me alot of digging! My "RMI" slide chart doesn't show anything smaller than 1/2 copper.
One more question, do I have to worry about electrolysis,with copper in black, in pvc? and if so where should the anode bag be attached to? The copper, or the black? I don't ever want to go through this again! better safe than sorry.

thanks again

Al

Unknown

No protection is needed

unless the copper and the black pipe are together making direct contact with the soil. If you protect both it should be okay. The problem is that with copper and black pipe and soil the copper is a good conductor and the black pipe will give up molecular material through the soil which acts as an electrolyte. No contact(with soil) no circuit and it will not be a problem.

Weezbo

Tim, this maybe a situational requirement in our area,

the propane lines that are supply side from the tank are intentionaly oversized ,and may pose problems during the winter when they are pulling at or near the rated lengths or capacities..This is something i questioned once and only once..and have since then upsized the supply side. when something has been inspected and passed with flying colours and as the inspector or installer one is called upon as to why this appliance isnt working correctly and it is found to deviate from the type size and original install are you saying it is no problem? When we got natural gas here i asked if there were any stipulations that the supply side piping be oversized and was assured that it wasnt a requirement or recommendation.Having said this many years ago ,when piping in some boilers built for the administrative complex for a hospital,i being unaware of that feature of natural gas ,i up sized it intentionally....the buildings got to the site and were assembeled and it was determined by the AHJ in Anchorage that due to the location of the service meter, the oversized pipe was the correct size and was only allowed to be installed on the existing system because of that point.now i had no way of knowing that at the time of my initial install as the buildings were built off site a,and i sized according to nat gas code and developed length.
just for clarification could you tell me why when some thing is correctly sized an inspector would make an adamant point of accepting the service providers recommendations rather than correctly calculated sized materials?

Unknown

If you are asking

me if it is okay to oversize piping my answer would be why not other than the cost to do so. I assume you are talking about piping after the gas meter or second stage regulator is that correct?