propane clearances - InspectionNews

John Arnold · #1 (**permalink**) 05-11-2007, 12:41 PM

I rarely see propane which is why I'm posting this photo. I know clearances have been discussed recently and I'm going to revisit those posts, but I'd be interested in any comments.
The big goose neck pvc pipe is a fresh air return intake, not combustion air. The small pvc pipe at the lower left is the furnace exhaust. All three windows are openable.

Jerry Peck · #2 (**permalink**) 05-11-2007, 02:08 PM

Whoa, that basement (or crawl space) could become full of leaking propane!

Among other things I see.

John Arnold · #3 (**permalink**) 05-11-2007, 04:36 PM

Thanks, Jerry
(obvious attempt on my part to put this back in the New Posts section without using "bump").
Aside from proximity to openable windows, and air intakes (and exhausts), I'm thinking the radon equipment could be source of ignition.

Scott Patterson · #4 (**permalink**) 05-11-2007, 04:46 PM

This might help.
I would say 10' from the Radon mitigation fan. 5' from the crawl space entrance.

John Arnold · #5 (**permalink**) 05-11-2007, 06:13 PM

Thanks Scott. I had already saved that illustration from a previous thread, plus CodeCheck has one.

Bob Harper · #6 (**permalink**) 05-11-2007, 06:44 PM

NFPA 58 3.2.2.2b"Cylinders alongside of buildings shall be located and installed so that the discharge from the cylinder pressure relief device is at least 3 ft horizontally away from any building opening that is below the level of such discharge. The discharge from cylinder pressure relief devices shall be located not less than 5ft. in any direction away from any exterior source of ignition, openings into direct vent (sealed combustion sysytems) appliances, or mechanical ventilation air intakes."

There is a lot more in "58 you need to consider above the three sketches like the one Scott showed, which, BTW is one for ASME containers. If these are ASME containers, it would apply; if DOT cylinders, then the first diagram inappendix I would apply. Most of the spacing rules require you to determine whether ASME vs. DOT, combined water capacity, and whether filled on site or not.

I zoomed in on those tanks and their support is inadequate in my opinion. One good Nor'easter and those tanks could roll down the hill. It would most likely break the high pressure pigtail btw tanks but could also leak out of the pressure relief (shouldn't but could). Have you ever seen liquid phase propane issuing out of a tank? It expands 270x. If it leaks from the high pressure pigtail, you could have a 150psi flame thrower. That would surely make it onto Youtube.

Note the vent line on that second stage regulator to the left of the window. See the two copper tubes? One comes out of the vent and runs back to the tank bonnet most likely. That is how they can put that reg. next to the window. Too bad the cylinders are too close to the openings and ignition source. Also note, those are two different size and make tanks. From the looks of things, the larger tank was added on as was some of that exterior piping.

John, I would reocommend those tanks be re-set on more stable ground away from the building. Maybe they could install a buried ASME tank away from trouble.

One major hazard I see is the lack of a shutoff at that second stage regulator. Code required in case of rupture, the gas can be shut off right there. That is no time to be fiddling with the tanks. Shut it off at the regulator first then at the tanks then call the propane supplier.

John Arnold · #7 (**permalink**) 05-11-2007, 06:51 PM

Bob - Thanks much. I already wrote up the poor support. I'll add the bit about a shut-off at that regulator.

John Arnold · #8 (**permalink**) 05-12-2007, 05:43 AM

Bob - Here's a detail shot of that regulator. There are two shut-off valves, one of the left, one on the right. Should there be other ones?

Bob Harper · #9 (**permalink**) 05-12-2007, 07:26 AM

Yes, those are downstream of the regulator. The gas enters from the copper line emerging from the ground and that's where there should be a shutoff.

Those shutoffs to appliances might actually comply with the IFGC if they were to meet 3 criteria:
1) be "readily accessible", which these are. You can walk up and operate them without step ladders, tools, remove panels, etc.
2) serve only that appliance. Anything else downstream of those shutoffs except one appliance each?
3) be lableled. If they put tags on them denoting to which appliance they shut off that would actually count.

While we're at it, that copper should have been sleeved in PVC or conduit, esp. where it penetrates the masonry wall.

HTH!
Bob

JD Johnson · #10 (**permalink**) 09-04-2008, 02:27 PM

I found this thread while searching for information about tank clearances. The clearances referenced in the diagram appear to apply to tanks that are filled on site. I have an application, where a gas log fireplace is fueled by a 20 gallon portable LP tank, located on the exterior of the home. The portable LP tank is about 5' from the A/C coil.

So my question is, can someone clarify if the clearances shown on the diagram posted in this thread apply to portable LP containers, or is there is a clearance requirement for portable LP containers?

Thanks much - Stay safe

Bob Harper · #11 (**permalink**) 09-04-2008, 03:23 PM

JD, there are three diagrams in Appendix I of NFPA 58 showing tank clearances. First, you have DOT "cylinders", which is what a 20 lb. tank is. Then you have one for aboveground ASME "containers" and one for belowground "containers". The tank markings will tell you if it is ASME rated. You can have DOT cylinders that are filled on site or portable.

A 20lb BBQ-type cylinder is waaay undersized for a gas log set and is hazardous. Being a DOt cylinder, it can be 5 ft. away from the compressor or other sources of ignition if other criteria are met such as the ignition source not being downhill from the regulator. Also, residential applications other than portable BBQ's must have two stage regulation.

HTH,
Bob

JD Johnson · #12 (**permalink**) 09-04-2008, 03:32 PM

Thanks Bob, I could not find those appendix online, so I appreciate your assistance.