What is Gas Fitting Supplies and Why Do We Use Them?

Fitting Designs and Installation Considerations

When choosing the correct fittings, you need to know the difference between female fittings, which are threaded on the inside, and male fittings, which close around a female fitting. Pipes tend to end in male fittings, and there will be times when you will use a street fitting which has both a male and female end. You also need to understand the difference between supply fittings and DWV fittings. 

Supply Fittings: Also known as pressure fittings, supply fittings rely on water pressure to maintain flow. They are used above ground to connect pipes that provide water to faucets and fixtures. There are a number of different designs available, each of which serves a special purpose.

• Designs: Tees are T-shaped fittings that divert water from one line to another. They have three identical female openings located at 90-degree angles from each other. Couplings are used to join the ends of two pipes in a straight line, while unions feature three separate pieces – a tail piece, thread piece and nut. With a union, you can connect or disconnect pipe in the middle of a line. They must be used when you are working with threaded pipe because you cannot screw pipe into both ends at once. Plugs are used to seal a fitting at the end of a pipeline to provide an easy setup for changes or additions that must be made to the line in the future.
• Features: Water supply fittings may be made of copper, PVC or CPVC. Crows feet tees connect a fourth pipe while elbow fittings, or ells, change the direction of a pipeline and feature two female threads. Elbows are most commonly curved at 45-degree or 90-degree angles. Street ells feature a female thread on one end and a male thread on the other. Use adapter couplings to connect a soldered or glued joint to a threaded joint. Caps are used to seal off the end of a pipe.

DWV Fittings: DWV stands for “drain-waste-vent.” These fittings use gravity to move used water and waste out of your house. DWV fittings alter the direction of waste flow gradually so it won’t get bogged down at any point. They are used with pipes that remove water from sinks, toilets and tubs. They also help in venting the drainage system by removing unwanted and noxious gases from your home. DWV fittings come in a wide range of designs.

• Designs: Elbow joints are available in a selection of angles ranging from 22.5 degrees to 90 degrees. Y-shaped fittings called “wyes” join two separate lines. A P-trap is attached beneath a sink, where it traps water in the arc of the fitting, sealing it in while preventing sewer gases from seeping into your house. Sanitary tees and long radius tees help with the removal of waste and water while vent tees have 90-degree angles for fittings used in the venting side of the system.
• Features: DWV fittings determine the slope of your piping system. As a general rule, slope pipe downward 1/4-inch for every horizontal foot of pipe. DWV fittings should be made from the same material as the pipes. Closet elbows connect a toilet to the main drain while wyes use a 45 degree angle to maintain an uninterrupted flow. Cleanouts offer a convenient way to unclog blockages in your drainage system.

Reduction and Transition Fittings: When two different sizes of pipe or pipe made from different materials need to be linked, special fittings are required. Reduction and transition fittings share similar designs. Reducer elbows, tees and wyes have one end that’s smaller than the other, allowing for the transition from one pipe size to another. They feature two female ends. Bushings function in the same way as reducers, but feature one male and one female end. Reducer couplings connect smaller diameter pipes with larger ones while transition couplings link copper or steel pipes to plastic ones. Some reducers reduce pipe more than one step in size. Dielectric unions are used when making the transition from steel to copper pipes.

Gas fittings are a unique brand of hardware because they only serve one single purpose: connecting gasses with the appropriate lines. These are the fittings that you would see when working with gasses like flammable propane or hazardous phosgene. The primary thing that sets gas fittings apart from other types of fittings is their thread. They are reverse threaded so that gas cannot accidentally be connected to air, water, or vent lines.

When it comes to connecting gas fittings with their appropriate lines, there are a number of potential uses. They can connect to gas mains, propane tanks, residential gas lines, explosives, and more. However, you need to know which fitting types are appropriate for your specific needs. 

Fitting Types

Selecting the right gas fittings depends on understanding when to use which type and for what application. There are more than a dozen different styles of gas fittings that you may need to refer to when working with gas lines. Here is the breakdown of a few of the more common types of gas fittings: 

• Adapter

  : Connects two pipes together that are not the same size through welding, soldering, or threading.

• Coupling

  : Connects two pipes that are similar to each other through welding, soldering, or threading.

• Sleeve

  : Connects two pipes together via fasteners such as screws – best used when you need a faster installation time.

• Union

  : Connection that is easily disconnected without the need for cutting.

• Cap

  : Covers the end of a pipe or attaches to a male connection.

• Plug

  : Covers the end of a pipe or attaches to a female connection.

In addition to the types of gas fittings that are used to join two different pipes running in the same direction, there are also fittings to change directions. These include elbows, tees, wyes, and cross-connections. 

Getting The Right Size

Once you know what type of fitting you need, it is important to determine the size. There is no such thing as a one-size-fits-all gas fitting. Instead, you must refer to the size of the pipe that you are going to be connecting to. Based in either millimetres or inches, this size will allow you to choose a connector that will fit snugly. 

Keep in mind that purchasing a connector that is either too big or too small will adversely affect the overall connection. The seal that should form could leak instead with the installation of an undersized part. 

Selecting Materials

Gas fittings can be made from a number of materials like aluminum, brass, cast iron, copper, steel, stainless steel, and different types of plastics. Make sure you understand exactly what type of gas you will be working with so that you can select the right materials. Choosing the wrong material for a particular gas could lead to corrosion and leaks.

Choosing the right gas fittings for your project should be taken seriously. With this short guide, you can start researching exactly what your project calls for. If you have any questions, your Winnipeg heating professional, Provincial Heating and Cooling, is ready to help answer your questions!