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Up Topic Welding Industry / General Welding Discussion / Building Propane Bottles
- - By hillbilly delux (***) Date 11-10-2012 03:09
I have two propane bottles on my fifthwheel located on an internal factory compartment.  When its hot outside they vapor off enough to run my washer while I take a hot shower and the water heater keeps up. Even though I am working in New Mexico, its been getting cooler and my usuall amineties that I have been used to (Such as heat up dinner and start a load of laundry and jump in the shower all at the same time) is no more unless my bottles are full.

   But there is good news and bad news.   I have got extra head room in the factory compartment.  Bad news is that buying a bigger bottle because of the manufacturing standard they all clear the head room but becomes just a little to wide. Since I have no intrest in carrying a very large bottle on the back of my truck while in transit.  I am proposing to build some myself.

   Just sch 20 and some end caps carbon and a threadolet on top tig weld and walla no big deal. I have got freebie acsess to radiograpghy and pressure testing in house.

Only problem I have tought of by building them myself is getting them filled. The stamps on the side still no big deal in my eyes. I can stamp numbers too.

What are your guys thoughts, any ideas, sch 20 to thin?
Any info welcome. I have never cut a propane bottle apart but would like to know what they are made of if there sandblasted internally ect.
Parent - - By DaveBoyer (*****) Date 11-10-2012 04:01
While I am suggesting that You DON'T build Your own, the 30# bottle I have cut measures .100"thk.
It doesn't look to be sand blasted, but looks to be made from cold finished stock.

Rust on the inside of an old bottle is not uncommon, I think the thickness must be sufficient to allow for some.

If You were a LPE, I guess You would be qualified to design Your own, I guess, and could wright Your own manufacturing and testing  specifications as well, I guess. Then just go ahead and build it at a pressure vessel shop willing to put thier name on it and have it tested.

You would need to have an accurate tare and water charge weight, and find a valve with the proper length vent tube to avoid overfilling. If less than 100# capacity, it will need an OPD valve, with the float set to the proper liquid level to allow for expansion.

So, are You a Liscensed Professional Engineer ?
Parent - - By hillbilly delux (***) Date 11-10-2012 05:12
Dave

   No I am not.  But I know enough to make an engineer look stupid at times from the many years as a high profile high pressure welder and now inspector.  Its not like I am gonna sell them I am just gonna make a few for myself. I understand your point and well taken. But I am not gonna spend the time nor money for some company that holds some variation of an R stamp when I know good and well I could just build it my self with alittle foot work in the understanding of a proper build.  I do plan on the OPD valve.   I hadn't planned on cutting one apart but this tare and water charge rate I am unfamiliar with and could you enlighten me. Maybe I will cut one of my old ones apart

I just figured and couple welds 100% pen shot and hydroed I should be to go.  I figured these to be ruffly about fifty to sixty pounders.   The vent tube that your talking about should just be a popoff valve right?  I could get scientific with a liquid float but with a schedule 20  seamless on ten inch hydroed to 450 and a pop off to 200 I should be good. While using a thirty pound OPD valve.
Parent - - By DaveBoyer (*****) Date 11-10-2012 05:35
Tare weight is what the empty cylinder weighs.

Water charge is what the ammount of water to fill to a level that allows for expansion weighs.

The vent tube sticks down to the safe level of the liquid in the tank allowing for expansion, assuming a verticle instalation.

The OPD valve has a float on it that floats on the liquid propane and shuts off the filling at the safe level. The OPD valve is specific to the size & shape of the tank, and how far it is from the bottom of the valve to the inside of the tank [not just the thread o let].

A 30# OPD valve is not sufficient for a taller cylinder of the same diameter.

This as well as all the other is required by law. The valve has a high pressure pop off built into it.

It is not as simple as it first apears. Can You weld it ? Yes. Can You design it ????

For these reasons, I suggest You don't.

Will a 40# or 60# factory built tank fit in the space ?
Parent - - By hillbilly delux (***) Date 11-10-2012 05:54
I would love for one too.  But do to ISO 9000 or other governing bodies there all the same that I have found as far as size and dimenson.   I havent been totally sold on building them yet just looking at aspects for the time being.  But I think the challenge could be fun and do able.  I figured the thirty pound OPD design with its safety features and my back up safety valve  should be better than lets say a larger OPD valve. Can I design it??? I think yes through research and thoughtfull design.  I am sure most welders that you know that are not just farm hacks tend to be meticulous and more designers.  Trust me on this without due research first there will be no arc struck.  Even more so when dealing with propellents.   I inspect on live gas lines while welders do hot taps. Thats my specialty.  I know where you are coming from.

If you have a pic of an open bottle could you please post it.
Parent - By DaveBoyer (*****) Date 11-10-2012 06:12
I have now way to post pictures. The bottle is just a seam welded tube with a stamped end on top & bottom, the tube laps over the ends, and it is welded together. The ofsets forming the laps are rolled before the blank is rolled into a tube. There is a threaded tube welded on where the valve screws in. This was a 30#. A 20# is just the ends, no tube between. 40# & 60# use a longer tube. They are all about 12" in diameter. 100# are about 14" diameter.

Nothing inside but empty space.

The OPD valve is made for a specific diameter and capacity of cylinder. Each size & shape has it's own. The vent tube is part of the valve, it's length is made specificly for that size cylinder.
Parent - By 99205 (***) Date 11-11-2012 20:58 Edited 11-13-2012 00:32
This sounds like something that's going to end up on "The Headlines News".
- - By 803056 (*****) Date 11-10-2012 05:48
Hillbilly;

Can I have your new work boots after the funeral?

Some things we do are really scary. However, if we are ignorant of the dangers, no problem, until something does goes wrong and then the lawyers sort out the details after the funerals.

Al
Parent - - By hillbilly delux (***) Date 11-10-2012 06:04
Al

   I am cheap.  I have found a pair of boots that I love and I have owned the expensive ones to but yes you can I am sure she would donate them to you lol cause I got three pair for 200.

Whats so scarry about a bottles under pressure we carry them on our trucks ect.  We just have to be respectful of it.  My welders weld on  live pressurized lines every day and alot of times hear lately its been around five hunded psi  .156 wall and I am down in the ditch with them. Just a food for thought.
Parent - - By DaveBoyer (*****) Date 11-10-2012 06:22
The point You seem to be missing, is that the liquid in the cylinder expands when it warms up. This make not just a little pressure like a gas warming up, the liquid is not compressable, and will come out, through the overpressure valve, or by bursting the cylinder.

It doesn't just come out a little at a time when it comes out the over pressure valve, quite a lot does, and being liquid, that makes for a whole lot of gas. This is a fire/explosion issue if it gets ignited.

I witnessed this first hand while saling on a boat. The cylinder had been over filled in Cuba, We were day sailing in Key West.

While boats are supposed to have an overboard drain in the propane locker, on this boat [NOT MINE] there was a hole broken through the fiberglass locker, direct access to the bilge. If it had blown, I would not be here to write this post now.

This is the only time I ever feared for My life on a boat, and I have about 25,000 miles under My keel.
Parent - - By 803056 (*****) Date 11-10-2012 06:31
Hillbilly: I hope the boots are the correct size.

Dave: with regards to your excellent comments, "whoosh".

There is cheap and there is stupid. Sorry to say that I sometimes fall into the latter category because I am too cheap to buy something I can build. I often spend $10 to save $1.

Best regards - Al
Parent - By hillbilly delux (***) Date 11-10-2012 06:55 Edited 11-10-2012 06:58
Al

  Your right there is cheap. The guy that spends a ten cents to save a dollar from time to time and the other is cheap.  One is conservitive and the other is ignorant and both land on one side of that fence or the other from time to time. I like to think I am smart and conservative but I have not always achieved successe always in the conservative value but I have always have had lesons learned in mistakes.
Parent - - By hillbilly delux (***) Date 11-10-2012 06:47
I understand. Just so ya know Dave and AL I am still gonna build them.....    But...... I think I might just get my mechanical engineer involed that I have on hand and have her design it before I build it.  She deals with propane all the time as one of the main terminals were building is propane.   I will get her the dimensions and have her figure it out. But before that just for the challenge I am gonna figure it out and compare it to her desigin just for fun.
Parent - - By fschweighardt (***) Date 11-10-2012 14:35
You might play hell getting a homemade cylinder filled.  Supposed to be a DOT stamp, Etc.  our guys are supposed to check for all of that stuff before filling
Parent - - By hillbilly delux (***) Date 11-10-2012 15:30
Yeah I thought about that.  I got a set of metal stamps I can punch some numbers. I might just scrap the whole idea for a set of propane blanket heaters or maybe a combnation of the two.  On second thought I think I will try the heaters first and if that dosent work then build some bottles.
Parent - - By SMTatham (**) Date 11-10-2012 16:20
If you are parked for several weeks; what about having the gas company set you a tank?
Parent - - By hillbilly delux (***) Date 11-10-2012 18:28
I dont think the trailer park would go for that since it is kinda an uppity one.  But not a bad idea.  Gosh I hope I am not stuck in this hell hole called Hobbs NM for that long.  You cant get me to go to ND but this place will be the next ND in a couple of years.
Parent - - By 46.00 (****) Date 11-10-2012 20:08
What does ND mean? I am also in Hobbs NM,maybe we could have a drink in Applebees one night!
Parent - - By hillbilly delux (***) Date 11-10-2012 20:24
We can definetly do that ND is North Dakota.  Send me a PM I am free on monday evening.
Parent - - By hillbilly delux (***) Date 11-10-2012 20:26
I am staying at the RV Villas and you?
Parent - - By Stringer (***) Date 11-12-2012 23:35
Really? Hobbs? Gas compression and transmission or something like that?
Parent - - By hillbilly delux (***) Date 11-13-2012 00:29
I do transmisson mostly but I am inspecting at the Hobbs station in between Hobbs and Seminole for Enterprise.
Parent - By WELDICCAWSCWI (**) Date 11-14-2012 16:37
i can't believe that any CWI would put out on a forum that they were willing to falsify a national board stamp. makes one
wonder what they would try and pull off on a job!!
Up Topic Welding Industry / General Welding Discussion / Building Propane Bottles

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