Today we received a call to quote out an underground gas line running from a large LP tank, to the associated residence.
Generally speaking, we don’t typically do work like this—if a person rents an LP tank from the LP distributor, they usually run their own line to the house, and we connect onto it from there to run to the water heater, furnace, etc. We do frequently run underground gas lines to out buildings, pool heaters, though, which perhaps qualifies us to speak on a matter of experience. That said, because this homeowner owns his own LP tank and simply buys the LP from the distributor, he is looking for help with the gas line.
In Wisconsin, we almost always see LP contractors bury soft copper lines connected with flare fittings. While this is allowed by local code, copper oxidizes and is easily damaged by impact (ex: shovels when digging, weed whips, etc). To the left is a picture that shows an underground copper line (approx. 20 years old) that has corroded to the point that it no longer holds gas pressure.
Instead of copper, we highly recommend people go with a Medium Density Polyethylene (MDPE for short). MDPE is a yellow plastic pipe that pretty much all major natural gas providers (ex: Excel Energy) use for their new gas lines. The plastic makes the pipe resistant to any corrosion, and it easily copes with the shifting of the ground during freeze/thaw cycles. Further, at the ends of this piping system, heavy grade steel piping is used (called a riser), which provides an armored durable point of termination at the house and source of gas. To the right is an example of a reinforced steel riser leading to MDPE gas line in the ground. The steel riser is significantly more durable than the copper riser shown above. While we do offer our customers the option to proceed with either the copper or the MDPE options, we highly recommend the more MDPE method; which will undoubtably outlast the copper counterpart.
MDPE underground gas piping is the preferred way to run gas underground to supply your heating needs. While it may be more expensive, it is definitely our first recommendation when designing underground gas systems. Please call Heidikin Heating, Electric, Plumbing & Well for all you gas piping needs!
Justin Leach
Manager, Heidikin Heating, Electric, Plumbing & Well
(715) 716-0700
service@goheidikin.com