Sched 80 PVC as propane locker

[Chotu]

Go for it. Nothing logically wrong with the design except when you need to open the locker or turn the propane off by the tank valve. Then it's a little sketchy because you might let a lot of propane out of the enclosure if a tank happens to be leaking.

[bcboomer]

There won't be a problem with propane leaking because of the overboard discharge.
Is this enclosure within the boat? I think the pressure testing is overkill but can't hurt.

[RaymondR]

Sounds like a reasonable plan.

Normally a gas locker has a lid which does not seal allowing air to enter at the locker top, pass down past the bottle and out the drain vent and overboard. It appears that your proposal does not intend a deck access, the enclosure being entirely within the hull. Since you will seal the lid to ensure no gas escape into the vessel it appears possible that an explosive gas/air buildup might occur because of the lack of a flushing flow through the enclosure. You might consider both a top vent hose into the enclosure from outside the hull as well as the bottom.

[CF32907]

CaptVR here,
Your ideas are commendable but totally superfluous. Number one, ABYC says you shall have an overboard vent from the propane compartment. So the 200psi chamber your building will be of no use. And if you have insurance, you are inspected to ABYC and USCG standards and requirements. Besides, did you stop and think that if you built this high pressure chamber, and you did have a leak, opening the three latches would leave out gases in a very large rush that could blow up your boat.
Don't try and re-invent the system that is truly safe, do it to ABYC guides and you will have a very safe system. Trying to re-invent the wheel could cause you more grief than you could possibly immagine. USCG and ABYC propane guides are virtually mirrored.
Unless your propane tanks are within 5' of your appliances, you have to have a solinoid valve on the tank to stop propane flow and the switch has to be within 5' of that appliance. That was the requirement when I was surveying. Also the tank or locker could not be stored below decks, the propane hatch had to be mounted no lower than deck level. Get a current copy of ABYC guides on propane and do it accordingly.
Also, some earlier reply talked about tanks. Iv'e seen steel, aluminum, high end graphite fiber. Special marine aluminum tanks can be very difficult to fill, U-Haul and some private stations will fill. A lot of cabs and all buses do not allow propane tanks, it's a hell of a hike to get it filled sometimes. Use the standard, run of the mill steel tank and virtually 10 places within a mile or two will exchange your tank, you get a fresh tank, no rust, and cheaper propane. Check a U-Haul, that gas will cost you 30% more.
Hope this gives you some insight. Capt. Vince Rakstis, RetMS

[wsmurdoch]

Originally Posted by BlackHeron

Interesting idea. I was thinking of something similar to store the little green disposable 2lb tanks on the rail. Up untill now we stored them in an inside pocket of the lifeline-mounted cockpit dodger, but they are exposed to moisture and salt spray, rusting out therefore something fierce. A PVC enclosure would protect them from most of the salt spray and rain.

We only use them as a backup for the 20lb tank mounted on the stern rail. We have a "steak-saver" attachment that allows us to hook the little disposable cylinders directly up to the hose that normally goes to the 20lb tank once it is empty.

We keep two 1 lb disposable propane cylinders in a 15 or 16" length of 4" sch 40 PVC-DWV pipe capped at one end and with the other end fitted with a female thread adaptor and screwed plug that has been 1/4" drilled to assure that there is no internal pressure. It stays in our propane locker with the drilled hole facing down. The cylinders slide nicely but tightly into the pipe. Its purpose is to keep the painted steel cylinders dry and rust free. We keep brass caps on both cylinders to further protect their internal discharge valves and have their little relief valves buried in Vaseline. The cylinders are rust free after years of little use.

We have them for two reasons. I occasionally use one with a propane torch attachment when I need a propane torch. More importantly, they are the backup to our 2x20 lb propane supply and were added after twice losing the last of our propane due to a leak and once arriving in Georgetown, Bahamas low on propane finding that Clarence's propane truck would not start, and no propane was available.

Bill

[bcboomer]

Propane sinks so I can't imagine a scenario where it would fill the container and rush out when the lid is opened. If there is a leak inside the container it would simply drain out. ABYC call for a 1/2" inside diameter for the drain hose.
An exterior hose to the top would cover all the bases.
I have both composite and aluminium tanks and have never had an issue refilling either type.

[Cheechako]

I see no problem with using pvc as long as you do the proper design like a bottom drain overboard for gas etc.
-But I dont think having it in a locker is a good idea regardless.
-First issue is the lid, in order for the drain/vent to work you need air to be able to get in to replace what drains out.
-If you have that then you risk fumes in the locker.

I have no idea what "however the boat is a deep keel boat" has to do with any of this?
Mount it to the stern pulpit? Forget the locker.

[skipperpete]

That schedule 80 PVC pipe is very heavy, have you considered using Schedule 40.

[CF32907]

Originally Posted by bcboomer

Propane sinks so I can't imagine a scenario where it would fill the container and rush out when the lid is opened. If there is a leak inside the container it would simply drain out. ABYC call for a 1/2" inside diameter for the drain hose.
An exterior hose to the top would cover all the bases.
I have both composite and aluminium tanks and have never had an issue refilling either type.

If you read his idea for a locker, it was to be unvented and have three latches to hold 220psi of pressure. That is where he was getting the pressure. Capt. Vince Rakstis, Ret. MS

[RaymondR]

Originally Posted by navman

I need to build a new propane locker, and I am considering Schedule 80 PVC pipe with welded end fittings. Schedule 80 is rated to 220psi.

I would keep this sealed cylinder (with an integrated vent for overboard discharge) in the lazarette, however the boat is a deep keel boat, so I want to be certain that the cylinder is safe stored in a PVC enclosure.

Thoughts?

We're assuming the bit in red implies a vent from the bottom with a gravity drain through the transom.

[GordMay]

Originally Posted by Chotu

Go for it. Nothing logically wrong with the design except when you need to open the locker or turn the propane off by the tank valve. Then it's a little sketchy because you might let a lot of propane out of the enclosure if a tank happens to be leaking.

The locker opening should be at the top.
Propane Storage Lockers:
“... equipped with gasketed cover which:
1 12.2.4.1 opens directly to the atmosphere outside the boat,
L12.2.4.2 opens only from the top,
1.12.2.4.3 latches tightly ...”
Pages 3 & 4 ➥ https://law.resource.org/pub/us/cfr/....A-01.1993.pdf

[ggray]

Originally Posted by Cheechako

in order for the drain/vent to work you need air to be able to get in to replace what drains out.

I would think a bottom drain of this size would allow propane to drain and air to enter at the same time.

If it were water instead of propane, the water would glug, glug, glug on out.

Huge difference in relative specific gravities in my example, but I think that would only affect the velocity of transfer.

[gonesail]

a gas locker is one thing I would not compromise. buy a good one from Trident and be done with it IMHO.

[sanibel sailor]

If there’s a drain, no pressure can build up in the locker beyond one atm, unless it is a catastrophic leak which should be exceedingly rare. There is however pressure in the tank, that’s where the propane leak comes from. If the leak then pressurizes the locker, it does not need an additional vent on top, it will just flow out the drain until it is equalized. People are way overthinking this.

[darylat8750]

Sounds like overkill but ok to me. I do question "weld" pvc. Just glue it. Works good lasts forever.