dslreports logo
 
    All Forums Hot Topics Gallery
spc
Search similar:


uniqs
33317
XXXXXXXXXXX1
Premium Member
join:2006-01-11
Beverly Hills, CA

XXXXXXXXXXX1

Premium Member

Second Stage Propane Regulator Vent Distances

Is anyone here familiar with the code specifics for the placement of second stage propane regulator (specifically the discharge vent) for residential installations? I think the official reference is here:

NFPA 58 sec 3.2.12.5

but I can't find the actual wording anywhere to confirm specifics. I'm trying to determine the required distances from the vent discharge point of the secondary regulator (on a 2-stage system, where underground tank has first stage regulator, then piping underground to house, then second stage regulator affixed to the house) from furnace intake, electrical outlets, sources of ignition (like generators), windows and doors, etc.

I may have my discharge point piped to a different location with PVC, and I'm trying to plan that movement based on code requirements. Thanks.
XXXXXXXXXXX1

XXXXXXXXXXX1

Premium Member

My understanding of those NFPA requirements is that the secondary regulator vent discharge point can't be within 3 feet of a building opening horizontally or lower. In addition, the point of discharge for a secondary regulator vent can't be within 5 feet in any direction of any exterior source of ignition, openings into direct vent appliances, or mechanical ventilation air intake.

The vent can be PVC piped away from the regulator itself to a point that meets the above code... it's the discharge point that can't be within those distances listed above.

Anyone else can confirm or refute that?

tp0d
yabbazooie
Premium Member
join:2001-02-13
Bulger, PA

3 edits

tp0d

Premium Member

I cant quote code, as the NFPA has taken free access offline, but if I needed to properly and safely vent a regulator, I would use 3/8" soft flare copper and extend it vertically to the eave of the house, with a 45° termination, and a screen over the discharge. I dont prefer a flammable pipe (pvc) for any gas piping, vent or not.

90% of the installs out there have no remote vent. Newer regulator designs have a flow limited vent. My natural gas regulator at my meter has no tapping for a remote, just a screen. My original regulator had no flow restrictor, so I bought a new one with a restricted vent, and also a built in 20"wc downstream relief.

-j
XXXXXXXXXXX1
Premium Member
join:2006-01-11
Beverly Hills, CA

XXXXXXXXXXX1

Premium Member

I have the 2004 edition of the NFPA 58 regulations on LP-Gas codes.

NFPA 58 sec 6.7.4.8 reads as follows:

"(5) The discharge outlet shall be located not less than 3 ft. (1 m) horizontally away from any building opening below the level of such discharge

(6) The discharge outlet shall also be located not less than 5 ft. (1.5 m) in any direction away from any source of ignition, openings into direct vent appliances, or mechanical ventilation air intakes."

So it's 3 ft. and 5 ft., officially. Time to take out the tape measure...
XXXXXXXXXXX1

XXXXXXXXXXX1

Premium Member

Click for full size
Click for full size
Click for full size
To meet code, secondary regulator needed to be back piped. There was only 3' distance from regulator vent (on the regulator itself) to electrical outlet on the deck and 3' to the furnace intake.

The PVC pipe is schedule 40 and discharges at least 8' from intakes and outlets, and 5' from gas grill. It's code compliant now
Zach
Premium Member
join:2006-11-26
Llano, CA

Zach to XXXXXXXXXXX1

Premium Member

to XXXXXXXXXXX1
Did you put some sort of screen on the end of the extension? If not, the wildlife will eventually make a home in there. I didn't see anything in the code regarding it but the lowest section looks like a good place for condensation to pool. During normal operation, very small amounts of air enter and leave the vent as the diaphragm moves. PVC pipe connected to a fuel gas regulator looks kind of weird....I guess I'm just too old to use anything but black pipe or, in some cases, copper tube. I know; get with the 21st century.
XXXXXXXXXXX1
Premium Member
join:2006-01-11
Beverly Hills, CA

1 edit

XXXXXXXXXXX1

Premium Member

said by Zach:

Did you put some sort of screen on the end of the extension? If not, the wildlife will eventually make a home in there. I didn't see anything in the code regarding it but the lowest section looks like a good place for condensation to pool. During normal operation, very small amounts of air enter and leave the vent as the diaphragm moves. PVC pipe connected to a fuel gas regulator looks kind of weird....I guess I'm just too old to use anything but black pipe or, in some cases, copper tube. I know; get with the 21st century.

Actually, I didn't do any of my propane installations, propane company did them all (I don't mess with propane... I let the pros handle that ). And code specifically allows schedule 40 or 80 PVC for backventing purposes- even though it doesn't "look" like it fits the rest of the installation (very uber modern )

But yes, screen from regulator was popped out of regulator and used on the end of the PVC extension to keep critters and such out. The "low section" is allowed under code. In my case it was really the only option.. I did question the propane tech about it, and he said it is very common and he's never seen a problem with it- but ultimately said that code allowed it.

In the event of a regulator failure, the discharge point is within code to not cause a fire... and that was obviously consideration number one.

jack b
Gone Fishing
MVM
join:2000-09-08
Cape Cod

jack b to XXXXXXXXXXX1

MVM

to XXXXXXXXXXX1
I'm surprised there's no requirement for a shut-off valve either before or after the regulator. I would put one in if this was mine.

What is the white gas "junction box" for the grill for?
XXXXXXXXXXX1
Premium Member
join:2006-01-11
Beverly Hills, CA

XXXXXXXXXXX1

Premium Member

Click for full size
Click for full size
said by jack b:

I'm surprised there's no requirement for a shut-off valve either before or after the regulator. I would put one in if this was mine.

Code requires shutoffs at the tank and at each of the appliances in the system, but not immediately before and/or after the regulator. If I want to stop flow to the system as a whole, I only have to go to the tank and shut off the main valve... pretty much like what you would do with a BBQ-grill 20# tank. Note the tech recommended (and I agree with) a disconnect right as the copper tubing meets the regulator piping. Code only requires a shutoff at each device, so the valve in the grill disconnect box is all that is required... but it's a nice feature to be able to shut off the deck propane as a whole if there is a problem and still be able to service the house's propane needs.
said by jack b:

What is the white gas "junction box" for the grill for?

It serves 2 purposes- obviously gas grill. Since I tapped off the side after the secondary stage regulator (low pressure), the propane company cut off the low pressure regulator at the grill and put a quick disconnect fitting on a short run of hose to the grill. I can plug the grill in or disconnect at will.

In addition, the short length of copper tubing is sized to carry the btu load of my portable propane generator ( »www.homedepot.com/h_d1/N ··· Id=10051 ) Since it's 13hp, at peak draw it needs about 130,000 btu of propane. A simple hose would not have supplied that, so they moved the grill box to the end of the deck using appropriately sized copper tubing to carry the load, removed the low pressure regulator from the generator (confirmed as low pressure by the manufacturer- Buffalo Tools), and made a quick disconnect fitting so I can connect that portable to my home propane system. I haven't shot pics yet as I still need the electrician to make the final connections with the inlet box back to my panel.