Piping Related Abbreviations N-R


NDE is an abbreviation of Non Destructive Examination, also called Non Destructive Testing (NDT).
Non Destructive Examination survey techniques by which we can get an impression of the quality of an item to consider this item without damaging them.
To detect different defects such as cracking and corrosion, there are different methods of testing available like, X-ray, Ultrasonic testing (UT), Magnetic-particle inspection (MT or MPI), Liquid penetrant testing (PT or LPI) etc..


NPS is an abbreviation of Nominal Pipe Size.
Nominal Pipe Size is a North American set of standard sizes for pipes used for high or low pressures and temperatures. The name NPS is based on the earlier "Iron Pipe Size" (IPS) system.


NPT is an abbreviation National Pipe Thread Tapered.
The American National Pipe Thread Tapered, is the best known and most widely used connection where the pipe thread provides both the mechanical joint and the hydraulic seal. NPT has a tapered male and female thread which seals with Teflon® tape or jointing compound.
ASME B1.20.1 covers dimensions and gaging of NPT pipe threads for general purpose applications.


OSBL is an abbreviation of Outside Side Battery Limits.
OSBL refers to systems (equipment pieces and associated components) that support several units. Typical OSBL equipment includes cooling towers, water treatment facilities, tanks farms, etc.


OS&Y is an abbreviation of Outside Screw & Yoke.
A valve design in which the threaded portion of the stem is outside the pressure boundary of the valve. The valve bonnet has a Yoke, which holds a nut through which the rotating stem rises as the valve is opened. The stem part inside the valve is smooth and is sealed so that stem threads are isolated from the flow medium.


PBE is an abbreviation of Plain Both Ends.
Plain Both Ends means that both ends of e.g. a pipe nipple are plain.
TOE / POE = Treaded One End / Plain One End
TOE / BOE = Treaded One End / Beveled One End
POE / BOE = Plain One End / Beveled One End
TBE = Treaded Both Ends
BBE = Beveled Both Ends


PED is an abbreviation of Pressure Equipment Directive arises from the European Community's Programme for the elimination of technical barriers to trade and is formulated under the "New Approach to Technical Harmonisation and Standards".
Its purpose is to harmonise national laws of Member States regarding the design, manufacture, testing and conformity assessment of pressure equipment and assemblies of pressure equipment.
It therefore aims to ensure the free placing on the market and putting into service of the equipment within the
"European Union and the European Economic Area".
Formulated under the New Approach the directive provides for a flexible regulatory environment that does not impose any detailed technical solution. This approach allows European industry to develop new techniques thereby increasing international competitiveness. The pressure equipment directive is one of a series of technical harmonisation directives for machinery, electrical equipment, medical devices, simple pressure vessels, gas appliances etc...


PFD is an abbreviation of Process Flow Diagram.
A Process Flow Diagram is a schematic representation of the flow of fluids within the process as they travel between processing units. This diagram shows flow direction, but has no indication of the instruments and devices needed to control the process or to ensure safe operation.


PI is a mathematical constant that is the ratio of any Euclidean circle's circumference to its diameter. PI is approximately equal to 3.14. Many formulae in mathematics, science, and engineering involve PI, which makes it one of the most important mathematical constants. For instance, the area of a circle is equal to PI times the square of the radius of the circle.



PMI is an abbreviation of Positive Material Identification.
Positive Material Identification provides alloy chemistry and grade ID information instantly using a handheld tube-based analyzer without having to transport, alter, or damage the material. PMI is also used to ensure that the parent material in vessels and pipe spools is composed of the correct composition and once the component is welded that the correct filler material was used.


PWHT is an abbreviation of Post Weld Heat Treatment.
Post Weld Heat Treatment is defined as one of heat treatments done after welding/machining to improve the chemical and mechanical properties of weldment or machined surfaces. In concept, PWHT covers many different potential treatments.


RF is an abbreviation of Raised Face, and designed for flanges.
The Raised Face type are the most applied flange type, and is easily to identify. It is referred to as a raised face because the gasket surfaces are raised above the bolting circle face. The height in Pressure Class up to 300 Lbs is approximately 1.6 mm, and in Pressure Class 400 up to 2500 Lbs the height is approximately 6.4 mm. Pressure rating of the flange determines the height of the raised face. The purpose of a RF flange is to concentrate more pressure on a smaller gasket area and thereby increase the pressure containment capability of the joint.


RFC is an abbreviation of Released For Construction.
RFC means that the release for construction (after Approved For Construction) is given...start the project.


RTJ is an abbreviation Ring Type Joint flanges.
Ring Type Joint flanges have grooves cut into their faces which steel ring gaskets. The flanges seal when tightened bolts compress the gasket between the flanges into the grooves, deforming (or coining) the gasket to make intimate contact inside the grooves, creating a metal to metal seal.

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