Installing LP line

I have just purchased a concession trailer (8x17),  however there is no gas line plumbing .  What is the best type of LP gas line  to use ?    I have seen rubber hose and I have seen tubing shielded inside of metal piping.    Also do they have to be inside the trailer or can they run underneath the body of the traile?   Is there any particular type required?  I have to go from the front  to the back where the fryer is.  Can anyone help?
 
Thanks in advance
 
Ray

if I had to go from frt to back on a trailer on the outside, or any part outside i would go with "black iron pipe" with proper sealing combpound on the threads, if going anything inside i would use the line that is shielded "flex" pipe.... first off i would contact a professional to make sure it's done right! not the place to skimp on $$.. I put a fryer in my trailer i had a local gas co. run the gas line #1 it was warrantee # 2 piece of mind (mine)# I know it's legal.. I also had to get all my fire suppression system checked by a reg. outfit and it needs to be checked every year

3/4 inch black iron pipe. I used BOTH gas tape ( yellow) and pipe dope on all connections outside and inside except where connecting equipment. I just used the tape. The less connections the better. I would also spray your pipes with Rustoleum black paint to coat them BEFORE install.   Check out the thread on mobile kitchen build where I installed the gas lines in mine.
http://www.roadfood.com/F...uild-info-m568476.aspx

Thagas company.
 
Thanks for the comments and concerns.  I believe I will have it installed professionally.   I agree peace of mind.  I know a few guys in the gas company.  Thanks again.

Any pipe lines exposed under the trailer should be iron pipe. Yellow Gas pipe tape AND pipe dope on the same threads is overkill and really should not be done. I prefer the tape (personal choice... less gooey) We are pulling straight off an LP tank and use brass T and gas hoses. We have short runs.

It's not really overkill. I only use it on the outside joints. It's a preference to do both or just one.  Not a safety factor.  I wish I could use hoses.

What is the different betwen 1/2 or 3/4 inch black pipe.  Will either size work? The individual told me that either will work.  He also said to get a 2 stage regulator and then used 1/2 inch and t off to th frye and grill.  Does this sound  OK?   I will have a spand of at least 8 fet and then 45 elbow to the tank (100) lb I also plan on 45 elbow then thru the flloor up to a t and then split to equipment.
 
Comments?

stay with 3/4" either will work, just 3/4 is bigger and more of a standard. it's not much cheaper to go 1/2. Also don't forget emergency shut off valves.

also ck your fryer and  or grill they may have regulators on them already... my fryer did...and dont tee off both grill and fryer off the same line. use two seperate lines for each from the main line that is where your flex lines come in. tee off the main line with flex to your equipment. and like wild dog said dont forget the shut off valves. main line, T , valve , then flex to equipment

I will stay with 3/4 inch line and will make 2 separate  con nection off the main line to the grill and fryer.  I also will make sure I have an emergency shut off valve as well and the proper  Ts.   I already have 2 location to cook at and real excited to get going.  
 
Thanks again
 
You have really helped