First time using MegaPressG for gas line retrofit

[CarlosJr]

I have a press tool with IPS jaws. I've previously done water plumbing with ProPress. I've never used it for gas before; all of my prior gas work has been threaded.

I would like to tap into an existing gas line which sits behind a garage drywall ceiling. I believe that the easiest way to do this is to use MegaPress gas fittings, rather than trying to thread on a left-right coupling. Based on my understanding of the requirements, MegaPressG is ANSI LC-4 listed and so it is approved for concealed locations:

Digital Codes

ICC Digital Codes is the largest provider of model codes, custom codes and standards used worldwide to construct safe, sustainable, affordable and resilient structures.

codes.iccsafe.org

https://www.viega.us/content/dam/viegadm/download-assets/en_us/tech-marketing/megapress/pocket-guides/PG-MP_724453_MegaPress_Systems.pdf

Is this accurate? Does anyone have prior experience with this? I'm in California so we do get earthquakes here. Viega claims that these fittings are OK for seismically active areas.

The installation manual uses some rather curious wording rather than saying "approved for use in concealed spaces":

The Viega MegaPressG fitting system has been examined according to the construction and performance criteria in the CSA requirement LC-4 and was found acceptable. Specific performance tests were conducted to evaluate the fittings for use in concealed locations.

I would also be interested in feedback on my intended procedure. The idea is to press a MegapressG MIP threaded end onto a freshly cut ******, after tightening the threads on both sides. This has the same end result of using an L/R coupling but without having to rethread and carefully "synchronize" the tightening step.

1. Turn off gas at meter
2. Let an appliance pilot light burn off the remaining pressure and self-extinguish
3. Open a gas outlet in an well-vented area (open garage) and let it sit for a few minutes to allow residual gas to escape
4. Near an existing threaded fitting, cut the pipe with a sawzall bit intended for cast iron. Remove old pipe and install new threaded ****** + tee
5. Measure + cut a fresh ****** to size using a rotary pipe cutter. One end factory-threaded, one end flat (for pressing)
6. Ream with a step drill bit and hand deburring tool
7. Sand down the surface with fine grit sandpaper where the MegaPress fitting will go
8. Ensure that there are no defects/markings on the pipe which impair a proper seal. Check inside of MegaPressG fitting for O-ring. Mark insertion depth
9. Tighten threaded end of ****** onto existing fitting with Rectorseal #5
10. Tighten new MegapressG MIP fitting onto the other threaded pipework with Rectorseal #5
11. Press MegapressG MIP fitting onto unthreaded (freshly cut) end of the new ******. Since it's 1/2" (jaws not ring), the pipe will deflect away from me, so pull in a little bit to compensate
12. Turn on gas and test all nearby joints with soapy water + gas sniffer meter

There is no pressure test because this is an old house, and my utility recommends against it due to the risk of damaging existing seals.

 

[danski0224]

Just cut it and put a union there.

 

[CarlosJr]

Can't have a union in a concealed area. Also the whole point of buying the MegaPress jaws (which weren't cheap) was so that I could avoid the messy and time-consuming process of cutting threads.

 

[fitter30]

When pressure testing gas line shutoff valves are closed except the furnace valve in the off position can use a manometer . Gas valve should have inlet pressure tap. Give you 7 - 8" pressure valve meter off 20 minutes doesn't drop your good. Soap bubble new fittings.

 

[CarlosJr]

When pressure testing gas line shutoff valves are closed except the furnace valve in the off position can use a manometer . Gas valve should have inlet pressure tap. Give you 7 - 8" pressure valve meter off 20 minutes doesn't drop your good. Soap bubble new fittings.

You're saying to test at 7-8" WC = ~0.25 PSI, but with air rather than gas?

 

[HoosierBuddy]

My only experience with MP was having a dealer donate all the fittings and use of the tool to help build a habitat for humanity house a few years ago. It seemed to work OK, but we didn't leave any fittings in concealed locations. If you have any questions, ask the manufacturer. They have people they pay to answer these questions.

I have to say, after the build, I was not left with any desire to go from threading pipe on future projects to MP. The fact the fittings would all spin after pressing kind of freaked me out. The dealer made sure that all the pipe was supported with pipe clamps, so not an "issue" but I'm used to threaded pipe where the pipe is pretty rigid and the "floppyness" of the MP assembled pipe kind of caught be off guard.

Anyway on your installation plan:

You need your own shutoff valve rather than using the one in front of the gas meter. That belongs to the gas company, and (if they are following federal Pipeline Safety Regulations) they won't want you to turn it. You could contact them, I'm sure, and they'd come out and shut it off. that would allow you to install a new valve on your own piping for future use.

Your gas pipe won't "self clear" of methane by leaving a valve open somewhere. If you want to get the gas out of it, purge it with air to push the gas back outside to a safe location.