Pipe Bushing 
Short pipe which has threading on the inside and outside diameter, along with wrench flats, for turning, at one end. Bushings can be used to change pipe sizes when other fittings cannot be used. 

Pipe Cap
Fitting to close off the end of a length of pipe. 

Pipe Clamp 
Designed for spanning wide work, it has a metal pipe with screw clamps and an adjustable stop mounted on the pipe. The clamping mechanism is positioned long the length of the bar to fit the appropriate size of the work with the length of the bar. Fine adjustments and clamping pressures are made by the screw threads on the clamp, which is also called a bar clamp. 

Pipe Coupling 
Pipe sleeve, which can be joined to other lengths, by being screwed into either end of the pipe, both of which are threaded. 

Pipe Cross 
Cross shaped fitting which can be used to connect four lengths of pipe. 

Pipe Cutter 
Apparatus, which consists of a sharp cutter wheel and a set of rollers that can clamp the circumference of any size pipe. The cuter wheel cuts a groove into the pipe when the cutter is clamped in place and rotated around the outside of the pipe. Every time the cutter is rotated around, the cut into the pipe wall gets deeper until it is severed.

Pipe Dope 
Compound which, when applied prior to joining, lubricates a pipe joint or seals the pipe threads when the pipe is joined. 

Pipe Ell 
Plumbing fitting, shaped like an elbow, which allows water to flow in a curve. Also referred to as an ell, it is designed to use with pipe, tubing, conduit, or duct and is available in 90 to 45 degrees. 

Pipe Fittings 
All parts used for joining pipe and bending or changing direction of piping such as tees, ells, bushings, adapters, couplings, etc. 

Pipe Flange 
Projecting rim or collar on a wheel or pipe which holds it in place, gives it strength or allows it to attach to another object. Often there are bolt holes circled around the outer edge of the rim, with bolts with nuts holding the two flanges together against a gasket that separates them.

Pipe Hanger 
Device which is used to hold piping in place. Hangers support pipes from above and are a necessary part of the piping system, because they keep the pipes functional and intact in spite of any problems. 

Pipe Joint 
Connecting piece between two lengths of pipe or lengths of pipe and fittings. Joints are threaded, welded, cemented, flanged, etc. depending on the kind of pipe being joined. 

Pipe Joint Compound 
Compound which, when applied prior to joining, lubricates a pipe joint or seals the pipe threads when the pipe is joined. 

Pipe Laser 
Laser beamed optical device which is used to align pipes by projecting the beam along the slope of pipe installation and beyond to some distant point. The pipe layer can keep a watch on the alignment of the piping by looking through the viewer to check if there is alignment with the light beam. 

Pipe Nipple 
Short length of pipe with male threading on each end, used in places where one is needed. 

Pipe Plug 
Male threaded plug, which seals the end of a run of pipe when fitted into a female threaded fitting. Plug has a slotted head or square head with wrench flats. 

Pipe Size 
Size of pipe up to 12 inches, after which the pipe size (nps for nominal pipe size) is the outside diameter. 

Pipe Sleeve 
Sleeve, constructed from a strong and durable material, which is passed through a wall, for the purpose of inserting other pipe through it and, therefore, through the wall. 

Pipe Street Ell 
Connector ell which has male threads on one end and female threads on the other so that it can connect a male end of pipe to a female end or can change direction without a joint. 

Pipe Supports 
Any and all devices such as straps, clamps, etc. which are used to hold piping in place. Hangers support pipes from above while spring supports can be used either above or below. Riser clamps support the weight of vertical pipes, while roller supports permit the pipe to move axially. A necessary part of the piping system, they keep the pipes functional and intact in spite of any problems. 

Pipe Tee
Fitting which joins three pipe lengths at a single junction. 

Pipe Threader, Ratchet 
A handle that is usable with a variety of die sizes, with a ratchet that can turn a die, even when it cannot do a full turn. Used with a die, it cuts threads into pipe ends. 

Pipe Threader, 3-Way 
Handle that has three sized pipe dies to use for cutting threads into pipe ends when the correct size die is fitted to the end of the pipe and the threader is rotated. 

Pipe Threads
Increased sealing ability is caused by use of tapered threads, when the pieces are joined and tightened. 

Pipe Vise 
Vise which grips the outside of a pipe by use of a chain or curved jaws so that it isn't flattened and can be used to hold pipe while cutting or threading and while fitting are installed. 

Pipe Wrench 
Adjustable wrench, also called a Stillson wrench, has serrated jaw surfaces to grip pipe and a movable jaw, at an slight angle to the fixed jaw, so that the angle increases the jaws' grip on the pipe, when it pivots slightly as force is exerted on the handle. 

Pipefitter
Contractor whose job is to install piping for steam, cooling, hot water, etc. 

Pipeline
System of pipes, which carry fluids over, distances, both great and small. 

Piping
Pipes, supports, fittings, valves and other components that make up the system for transporting or containing gas or liquid from one place to another. 

Piping Area Drawing 
Drawing, done by the layout person for the piping system, which shows, to scale, the routing of the piping system using either elevation views or plan and section views. 

Piping Codes and Standards 
Codes applicable to piping and piping systems are established by local and state laws. Materials are covered by American Society for Testing and Materials (ASTM) Standards with other regulations being set by American Society of Mechanical Engineers (ASME), American Petroleum Institute (API), American Water Works Association (AWWA), American National Standards Institute (ANSI), American Welding Society (AWS), Manufacturers Standardization Society of the Valve and Fitting Industry (MSS), Plastics Pipe Institute (PPI), Copper Development Association (CDA) and the Uni-Bell PVC Pipe Association. 

Piping or Tubing, Copper 
Tubing or piping either thin Type M, medium Type L and heavy wall Type K, which can be either rigid, called Drawn Temperature Pipe or flexible, called Annealed Tubing, all of which is made from copper alloy. The outside diameters range from ¼ inch to 12 inches with connections made of compression fittings, solder joints and flare fittings with threaded joints normally used for piping.

Piping Isometric Drawing 
Three-dimensional drawing that shows the layout, sizes and dimension of the piping system of a structure. 

Piping, PVC 
Polyvinyl chloride, a lightweight, resilient, chemical resistant, strong and durable thermoplastics, with an long lifespan, made into piping which is often used for cold water systems and where chemicals are found. There is bell and spigot pipe, with a bell on one end, which has an internal elastomer seal to hold the lubricated plain end of the next piece of pipe, by making a fluid-tight joint. Solvent cement joint pipe joins the ends by applying a primer to soften the surface of the material, with the solvent cement being applied to the pipe end and the inside of the fitting end, then inserting the pipe into the fitting using a twisting motion to spread the solvent cement. The cement cures rapidly and the joints fuse together. 

Piping Schematic 
Schematic drawing, which shows the routing of the piping system of a structure, without showing the piping lengths or giving dimensions. 

Piston
Solid cylinder within a cylinder pumping and compressing fluid as it moves back and forth. 

Piston Ring 
Spring steel ring that provides a seal against the cylinder wall when it is fit around the outside of a piston. 

Piston Rod
Rod that has bearings at each end and connects the piston to the crankshaft to transfer power. 

Pit 
1. A hole or cavity in the ground. 
2. A hollow or depression on a surface. 
3. An area below floor level or ground level. 

Pitch
1. Slope of a roof. Pitch is the ratio of vertical rise to horizontal run. 
2. To toss at a mark. 
3. The key or high or low of an instrument or voice.
4. To fall or plunge headlong.
5. To incline downward. 
6. The number of threads or teeth per inch. 
7. Resin substance from tar residue. 
8. Amount of turns of a spiral per unit length. 

Pitch Board 
Template for building stairs, which is cut in the identical size and shape of the preferred stair stringers to be used to make duplicates. 

Pitch Diameter 
Threaded cylindrical object diameter at a midway point between the diameter at the root or base of the threads and the maximum outside diameter of the threaded portion. 

Pitch Seam 
Wood defect that occurs when a check or shake is filled with pitch.

Pitch Wall 
Wall whose upper plate slopes to match that of the roof. 

Pith
The soft inner part of a tree that has very little structural strength, making it not usable for framing or where structural strength is needed. 

PITI (principal, interest, taxes and insurance) 
Payment amount calculated to include the principal, interest, taxes and insurance on an amortizing loan and represents the borrower's actual monthly mortgage-related expenses.

Pitot Tube 
Device which measures the fluid flow difference between static and dynamic pressure and is used in fluid systems to monitor operating characteristic and fluid velocity. 

Pitting
1. Defect that occurs when paint has tiny bubbles that break as the paint dries. 
2. Spotted metal corrosion. 
3. Drywall defect of small pits in the joint compound after drying. 

Pivot 
1. A point or shaft on which something turns. 
2. Hinge point between two objects.