How do you join gas pipes - Best way to join steel gas pipe

 Looking to connect gas pipes to your home? Richard Trethewey, This Old House's plumbing and heating expert, discusses the "press-connect" technique, a novel way to join gas lines.

Steel pipes are used to transmit gas from the primary source in the building to numerous appliances. It is customary to cut the pipe to size, thread it, and then join it with fittings that have opposite threads of the same size.

The "press-connect" technique, recently adopted by code standards, is becoming more popular in the United States.

Please note: Only a trained professional should connect gas pipes.

Press-Connect Gas Pipe Connection Instructions: 

1. Create a length of pipe.

The pipe is cut to length using a band saw or miter saw fitted with a blade for cutting heavy metals.

2. Take out the burs

The cut edge is polished with an emery cloth to ensure it is bur- and scratch-free.

3. Dry-fit and note the depth of fitting.

Dry-fit the fitting and note the position of the pipe so that the pipe fits perfectly into the fitting. Make sure the fitting is within the recommended depth specified by the manufacturer by measuring the distance.

4. Tighten the fasteners

Apply the fitting once more and tighten it with a special crimping tool. This tool, which was specially developed for the job, ensures that the fitting is given the correct amount of torque.

How to connect gas pipes the old fashioned way:

1. Create a length of pipe.

The pipe is trimmed to the correct length using a power pipe threader.

2. Rewind the pipe

After the pipe is cut to the desired length, a pipe reamer is used to clean the inside of the cut end. In this process, excess material present after cutting is removed, narrowing the inner diameter. This eliminates any potential friction that could affect the gas flow rate due to re-opening.

3. Organize the pipe.

The end of the pipe is threaded with a tapered thread using a special pipe threading die. They gradually become shallower as the thread moves away from the end of the pipe. During the step, pipe threading uses oil to control heat build-up

4. Thread dope, please.

Gas-rated pipe dope is applied to the threads after thread cleaning to remove excess oil.

Add fittings to 5.

After that, the fitting is inserted and tightened using two wrenches.