3. INTRODUCTION
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 (or measuring) fluid flow.[1] 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.
Fittings (especially uncommon types) require money, time, materials, and
tools to install, and are an important part
of piping and plumbing systems.[2] Valves are technically fittings, but are
usually discussed separately.
4. CONTENT
Materials:-
The material with which a pipe is manufactured is often the basis for choosing a pipe. Materials used for manufacturing pipes
include:
•Carbon (CS) and galvanized steel
•Impact-tested carbon steel (ITCS)
•Low-temperature carbon steel (LTCS)
•Stainless steel (SS)
•Malleable iron
•Chrome-molybdenum (alloy) steel (generally used for high-temperature service)
•Non-ferrous metals (includes copper, inconel, incoloy, and cupronickel)
•Non-metallic (includes acrylonitrile butadiene styrene (ABS), fibre-reinforced plastic (FRP), polyvinyl chloride (PVC), chlorinated
polyvinyl chloride (CPVC), high-density polyethylene (HDPE), and toughened glass; polybutylene has also been used, but is now
banned in North America because of poor reliability)
The bodies of fittings for pipe and tubing are most often the same base material as the pipe or tubing connected: copper, steel, PVC,
CPVC, or ABS. Any material permitted by the plumbing, health, or building code (as applicable) may be used, but it must be
compatible with the other materials in the system, the fluids being transported, and the temperature and pressure inside (and
outside) the system. Brass or bronze fittings are common in copper piping and plumbing systems. Fire
resistance, earthquake resistance, mechanical ruggedness, theft resistance, and other factors also influence the choice of pipe and
fitting materials.
5. Common piping and plumbing fittings
Adapter:-
•any fitting that connects pipes of different materials, including:
• expansion adapters which have a flexible section to absorb expansion or
contraction from two dissimilar pipe materials
• mechanical joint (MJ) adapters for joining polyethylene pipe to another
material
• bell adapters which are like mechanical joint adapters but contain a
stainless steel backup ring to maintain a positive seal against the mating
flange[
• flange adapters which attach to a polyethylene pipe with butt fusion to
stiffen a junction and allow another flanged pipe or fitting to be bolted
•a fitting that connects pipes of different diameters, genders, or threads
• adapter spools (also called crossover spools), used on oilfields and
pressure control, have different diameters, pressure ratings or designs at
each end
• adapters to convert NPT to BSP pipe threads are available
•a fitting that connects threaded and non-threaded pipe
6. Coupling
A coupling connects two pipes. If their sizes differ, the fitting is known as a reducing
coupling, reducer, or an adapter. There are two types of couplings: "regular" and
"slip". A regular coupling has a small ridge or stop internally, to prevent over-insertion
of a pipe, and thus under-insertion of the other pipe segment (which would result in an
unreliable connection).
A slip coupling (sometimes also called a repair coupling) is deliberately made
without this internal stop, to allow it to be slipped into place in tight locations, such as
the repair of a pipe that has a small leak due to corrosion or freeze bursting, or which
had to be cut temporarily for some reason. Since the alignment stop is missing, it is up
to the installer to carefully measure the final location of the slip coupling to ensure that
it is located correctly.
