When gas comes into your home from its main source, steel pipes distribute it to your appliances. Traditionally, plumbers or gasfitters connect the piping, thread it to size, and fit it with opposing threads of the same size. However, a newer “press-connect” method is rising in the United States since it was adopted by code standards. This Old House’s Richard Trethewey and his apprentices demonstrate how it works.
PLEASE NOTE: Gas pipe connections should always be done by a licensed professional.
Press-Connect Method for Steel Gas Pipes
The press-connect method is a faster, potentially more efficient way to work with steel gas pipes. It’s ideal for new installations, retrofit projects where minimal disruption is preferred, and tight spaces where threading equipment can’t fit. And, according to Trethewey, it only takes about a minute per connection. “It really adds up when you have a lot of gas connections,” he says.
First, a professional measures and marks the pipe according to plans. Then, they make a clean cut and remove burrs and rough edges with emery cloth.
Once the cut is complete and smooth, they slide the press-connect fitting onto the pipe and mark the appropriate insertion depth. If everything checks, they use a special tool to finalize the connection. “It has special jaws for each size of fitting, it’s battery operated, and it puts just the right amount of torque to compress this fitting,” says Trethewey.
Traditional Method for Connecting Steel Gas Pipes
The traditional method involves several different precise steps. Professionals use it for older systems with existing threading, in areas where press-connect fittings aren’t available, and where each fitting requires precision and care. This time-tested approach has been used for decades and remains a reliable option for many plumbing professionals.
First, a worker measures and marks the pipe to the desired length then secures it in a power drive. “This is what I grew up on,” Trethewey says of the tool, which resembles a woodworking lathe. The power drive has attachments to cut the pipe, ream it to smooth the inside edges, and thread it so it can be attached to fittings.
Before the worker takes the pipe off the power drive, they’ll need to wipe the excess cooling oil, apply pipe dope for leakproofing at the threads, and attach the fitting. Finally, they tighten the fitting with two wrenches for the most secure seal.