The larger-diameter hub was also called a “bell” because of its shape. Adequate ventilation is essential to remove metal fumes from welding operations, and personal protective equipment must be worn. Because the high temperatures during welding can often generate intense ultraviolet light, dark goggles or full face shields must be used to protect the eyes.
Oil the thread of the union nut, the cutting ring and the screw sleeve thread. In these threaded connections, the cutting ring has been pre-assembled by the manufacturer. The sealing cone is fitted with an O-ring and is shaped so as to fit precisely inside the mating part of the threaded connector. Although flare connections are labor-intensive, they are durable and reliable. Considered more secure against leaks and sudden failure, they are used in hydraulic brake systems, and in other high-pressure, high-reliability applications. Properly welded joints are considered reliable and durable.
It must be installed in an easily accessible place for adjustment, replacement, and repair. A trap primer, a specialized valve, is usually connected to a clean-water supply in addition to a DWV system. Because of the dual connection, it must be designed to resist the accidental backflow of contaminated water. Underground piping systems for landscaping drainage or the disposal of stormwater or groundwater also use low-pressure gravity flow, so fittings for these systems resemble larger-scale DWV fittings.
A tee, the most common pipe fitting, is used to combine or divide fluid flow.Tees can connect pipes of different diameters or change the direction of a pipe run, or both. Available in a variety of materials, sizes and finishes, they may also be used to transport two-fluid mixtures. Tees may be equal or unequal in size of their three connections, with equal tees the most common. In short radius elbow, centreline radius is the same as the nominal size of the pipe or you can say one times the diameter of the pipe.
The joint is then heated, typically by using a propane or MAPP gas torch, although electrically heated soldering tools are sometimes used. Once the fitting and pipe have reached sufficient temperature, solder is applied to the heated joint, and the molten solder is drawn into the joint by capillary action as the flux vaporizes. “Sweating” is a term sometimes used to describe the soldering of pipe joints. Assembling threaded pipe is labor-intensive, and requires skill and planning to allow lengths of pipe to be screwed together in sequence. Most threaded-pipe systems require the use of strategically located pipe-union fittings in final assembly. Threaded pipe is heavy, and requires adequate attachment to support its weight.
A tee is steadier than a cross; it behaves like a three-legged stool, and a cross behaves like a four-legged stool. A fitting or adapter is used in pipe systems to connect straight sections of pipe or tube, adapt to different sizes or shapes, and for other purposes such as regulating fluid flow. These fittings are used in plumbing to manipulate the conveyance of water, gas, or liquid waste in domestic or commercial environments, within a system of pipes or tubes. Pipe fittings are essential for all plumbing applications.