Connecting steel gas pipes requires precision, skill, and adherence to safety standards. Whether you’re a homeowner looking to understand the process or a professional seeking to expand your knowledge, this guide will walk you through the traditional and modern methods of connecting steel gas pipes. We’ll cover everything from the tools and materials needed to step-by-step instructions for both the traditional threading method and the newer press-connect technique that you find in the above video featuring This Old House plumbing and heating expert Richard Trethewey.
Important: Only licensed professionals should connect gas pipes. Improper installation can lead to gas leaks and pose serious safety risks. This guide provides insights into the process but is not a substitute for professional training and certification.
Safety Precautions When Working With Gas Pipes
Safety is always the priority when working with gas pipes. The risks of gas leaks mean that strict safety protocols should be followed, and only qualified people should handle these tasks. Proper safety measures can prevent accidents and mishaps in gas pipe connections.
Required Certifications and Licenses
Working with gas pipes requires specific certifications and licenses. These vary by location but typically include:
- Gas fitting certification
- OSHA safety training certification
- State or local plumbing license
Always check your local regulations to work within compliance with all necessary requirements before attempting any work on gas systems.
Safety Equipment
When working with gas pipes, the following safety equipment is required:
- Fire extinguisher
- Gas leak detector
- Proper ventilation equipment
- Safety glasses
- Work gloves
Never attempt to work on gas pipes without the appropriate safety gear and a thorough understanding of the risks involved.
Tools and Materials to Connect Steel Gas Pipes
The tools and materials needed depend on whether you’re using the traditional threading method or the press-connect method.
Gather the following tools for the traditional threading method:
- Gas-rated pipe dope
- Pipe cutter or power pipe threading machine
- Pipe reamer
- Pipe threading die
- Pipe threading oil
- Pipe wrenches
For the press-connect method, have the following tools on hand:
- Emery cloth
- Pipe cutter (band saw or miter saw with metal-cutting blade)
- Press-connect fittings
- Specialty crimping tool
Step-by-Step Guide: Traditional Threading Method to Connect Steel Gas Pipes
The traditional threading method is widely used and involves several key steps to create a secure connection. 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 remains a reliable option for many plumbing professionals.
Here’s a detailed breakdown of the process:
- Cutting the pipe to length: Using a power pipe threading machine, cut the steel pipe to the required length. “This is what I grew up on,” Trethewey says of the tool, which resembles a woodworking lathe. Make sure the cut is clean and perpendicular to the pipe’s axis for proper threading.
- Reaming the pipe: After cutting, use a pipe reamer to clean up the inside of the cut end. This step removes excess material that may have narrowed the interior diameter during cutting, which could impact gas flow rates.
- Threading the pipe: Apply pipe threading oil to the end of the pipe and use a specialized pipe threading die to cut tapered threads into the pipe end. The threads should gradually become shallower as they move away from the pipe end. The threading oil helps manage heat buildup during the cutting process, extending the life of the threading die.
- Applying pipe dope: Once threading is complete, wipe down the threads to remove excess oil. Then, apply gas-rated pipe dope to the threads. This compound helps create a gas-tight seal when the fitting is attached.
- Attaching the fitting: Finally, attach the appropriate fitting to the threaded pipe end. Use two wrenches to tighten the connection—one to hold the pipe steady and another to turn the fitting. Check that the connection is tight but be careful not to over-tighten, which could damage the threads or fitting.
Step-by-Step Guide: Press-Connect Method to Connect 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.
Here’s how professionals connect steel gas pipes using this modern technique:
- Cutting and preparing the pipe: Use a band saw or miter saw equipped with a metal-cutting blade to cut the pipe to the required length. After cutting, use an emery cloth to clean the cut end, making sure it’s smooth and free of burrs.
- Dry-fitting and marking: To make sure the pipe sits fully into the fitting, dry-fit the press-connect fitting onto the pipe end. Mark the insertion depth on the pipe according to the fitting manufacturer’s recommendations. This step achieves a proper seal.
- Crimping the fitting: Remove the fitting, then reapply it to the marked position on the pipe. Use a specialized crimping tool designed for press-connect fittings to crimp the fitting onto the pipe. This tool applies the correct amount of pressure to create a secure, gas-tight seal. “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,” explains Trethewey.
Comparing Traditional and Press-Connect Methods to Connect Steel Gas Pipes
Both methods have their advantages and disadvantages. Understanding these can help you choose the most appropriate technique for a given situation.
Pros and Cons of Traditional Threading
Below are the benefits and disadvantages of traditional threading.
Pros:
- Easier to take apart and reassemble
- Can be cost-effective for smaller jobs
- Reliable and time-tested
Cons:
- Takes more time
- May leak if threaded incorrectly
- Requires more skills and tools
Pros and Cons of the Press-Connect Method
Here are some pros and cons of the press-connect method.
Pros:
- More consistent results with less room for error
- Faster installation time
- Requires fewer specialized skills
Cons:
- Less flexible for future changes
- Not always suitable for all projects
- More expensive fittings and tools
Common Mistakes To Avoid When Connecting Gas Pipes
Even small mistakes can have serious consequences when working with gas pipes. Here are some common errors to avoid:
- Attempting DIY gas pipe connections without proper training
- Skipping permits and inspections
- Failing to test for leaks after installation
- Over-tightening threaded connections
- Using incorrect or incompatible materials
Maintenance and Inspection of Gas Pipe Connections
Regular maintenance and inspection of gas pipe connections lead to long-term safety and efficiency.
Regular Inspection Checklist
Here are some points of regular inspection you should conduct:
- Check for visible signs of corrosion or damage
- Check that all shut-off valves are accessible and functioning correctly
- Inspect fittings for any signs of looseness
- Test all connections for leaks using approved methods
- Verify proper gas pressure at appliance connections
Signs of Potential Gas Leaks
Be aware of these potential indicators of a gas leak:
- Abnormal behavior of gas appliances
- Bubbles in standing water near gas pipes
- Dead or discolored vegetation around buried gas lines
- Hissing or whistling sounds near gas lines
- Unusual odor (gas companies add a distinctive smell for detection)
If you suspect a gas leak, leave the area and contact your gas company or emergency services immediately.
