Pipe fittings are used in many industries, but they're most prominent in the plumbing, HVAC and fire prevention sectors. A variety of materials are used for pipe fitting projects, which can be blended together to create combination fittings. Combination fittings use either male or female threaded fittings in tandem with insert or compression fittings to increase their versatility.
PVC Pipe Fittings
Polyvinyl chloride (PVC) makes flexible piping which is often used in irrigation applications. It is also frequently used to make sewer pipe fittings and other plumbing fittings, since the plastic maintains its strength and flexibility when exposed to water, and is therefore less likely to break. The pieces can connect through both PVC fittings and PVC cement. PVC pipe fittings are available in a range of sizes, from ½ an inch to 12 inches. This allows you to connect PVC piping with vertical lines made of polyethylene, which is one of the most common materials used to make irrigation pipes.
When connecting PVC pipes with solvent chemicals, make sure you have plenty of ventilation in the area. Most of the chemicals emit fumes that are dangerous when inhaled in large quantities.
Your pipe fittings should be made of material that's similar to what the pipes themselves are made of. Metal pipes and fittings should be made from substances that are fully annealed to ensure they remain slightly flexible. This makes it less likely that the pipe will snap from pressure alone.
Brass fittings are used for plumbing, since they can resist the corrosive effects of water, heat, acids and minerals; they're also common for applications involving oil, gas and steam. More rarely, brass is used for potable water distribution. Because brass contains a small amount of lead, PVC pipe and other materials are more often used to distribute drinking water.
Stainless steel fittings are used for a variety of industrial applications, but their primary advantage is that they will retain their shiny, new appearance for years. This makes stainless steel the perfect material to use if the pipes and fittings will be visible to customers or the general public.
When welding pipe fittings, or when applying heat to them, you should take out all the components, including the bolts, nuts, seals and O-rings, to maintain the integrity of the connectors. A flame shield can help keep the propane from accidentally starting a fire nearby. Make sure you use lead-free solder on any lines that will be carrying water.