Rabu, 19 Januari 2011



Non destructive examination (NDE), also called Non destructive testing (NDT) 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) et cetera.


Threaded Both Ends means that both ends of e.g. a pipe nipple are threaded, as in the example below is shown.

Other abbreviations

• TOE / POE = Treaded One End / Plain One End

• TOE / BOE = Treaded One End / Beveled One End

• POE / BOE = Plain One End / Beveled One End

• BBE = Beveled Both Ends

• PBE = Plain Both Ends

Heat Number

The finished product from a manufacturer (the pipe or fitting mill), is typically traceable to a heat number (steel mill identification).

A heat typically identifies material produced in the steel mill from one single melt, and the number will be assigned in the steel mill.

Chemical analysis is usually reported on a heat basis. Parts of a same heat have the same chemistry.


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...

SR Elbow

Elbows are split into two groups which define the distance over which they change direction; the center line of one end to the opposite face.

This is known as the "center to face" distance and is equivalent to the radius through which the elbow is bent.

The center to face distance for a Short Radius elbow is even to nominal pipe size, while the center to face distance for a Long Radius elbow abbreviated LR always is 1½ x Nominal Pipe Size (1½D).


Originally Electric Resistance Welded which contains a solid phase butt weld, was produced using resistance heating to make the longitudinal weld (ERW). Most pipe mills now use high frequency induction heating (HFI) for better control and consistency.

However, the product is still often referred to as ERW pipe, even though the weld may have been produced by the HFI process


A Socket Weld is a pipe attachment detail in which a pipe is inserted into a recessed area of a valve, fitting or flange.

Socket weld fittings are mainly used for small pipe diameters (Small Bore Piping); generally for piping whose nominal diameter is NPS 2 or smaller. To join pipe to valves and fittings or to other sections of pipe, fillet-type seal welds be used.

LR Elbow

Elbows are split into two groups which define the distance over which they change direction; the center line of one end to the opposite face.

This is known as the "center to face" distance and is equivalent to the radius through which the elbow is bent.

The center to face distance for a Long Radius elbow, abbreviated LR always is 1½ x Nominal Pipe Size (1½D), while the center to face distance for a Short Radius elbow, abbreviated SR even is to nominal pipe size.


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.


Gas Tungsten Arc Welding, also known as tungsten inert gas (TIG) welding is a process that produces an electric arc maintained between a nonconsumable tungsten electrode and the part to be welded.

The heat-affected zone, the molten metal and the tungsten electrode are all shielded from atmospheric contamination by a blanket of inert gas fed through the GTAW torch.

Inert gas (usually Argon) is inactive or deficient in active chemical properties.

The shielding gas serves to blanket the weld and exclude the active properties in the surrounding air. Inert gases such as Argon and Helium do not chemically react or combine with other gases.

They pose no odor and are transparent, permitting the the welder maximum visibility of the arc.


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.

More about Nominal Pipe Size can be found: Menu > Pipes > NPS and Schedule


Cutting processes that use intense heat, like oxyfuel cutting and plasma arc cutting, produce thermal effects near the edge of the cut that lead to microstructural and metallurgical changes in the metal.

The portion of a metal work-piece that has been so altered by heat is termed the heat-affected zone or HAZ. All thermal cutting processes create an HAZ in the cut metal.


A Certified Material Test Report attesting that the material is in accordance with specified requirements, including the actual results of all required chemical analyses, tests, and examinations


The Welder Performance Qualification document is required by all codes for all welders. It details and summarizes the following information:

• Indicates the WPS referenced during the qualification test

• Identifies the welder by name and/or clock number

• Lists what the essential parameters were during this test

• Reports the results of the required qualification tests

• Specifies qualified limits for welder

For most codes there is a time limit associated with the welder qualification test. However, the American Welding Society provides an unlimited qualification period if certain conditions are met. As with the WPS and WPQR, each code has a recommended form


Magnetic Particle Inspection is a nondestructive examination method to locate surface and subsurface discontinuities in ferromagnetic materials. The presence of discontinuities is detected by the use of finely divided ferromagnetic particles applied over the surface. Some of these magnetic particles are gathered and held by the magnetic leakage field created by the discontinuity.

The particles gathered at the surface form an outline of the discontinuity and generally indicate its location, size, shape, and extent.


The Welding Procedure Specification is a required document for all code welding. Your customer either directly or indirectly specifies to what code your company must qualify. The WPS outlines all of the parameters required to perform your welding operation.

In short the WPS is the recipe for your welding operation. It describes the welding process or processes used, the base materials used, the joint design and geometry, gases and flow rates, welding position and includes all of the process conditions and variables. Each code has a recommended format.


TIG is an abbreviation of

Tungsten Inert Gas

see GTAW


Metal Inert Gas or Gas Metal Arc Welding (GMAW) is frequently referred to as MIG welding. MIG welding is a commonly used high deposition rate welding process. Wire is continuously fed from a spool. MIG welding is therefore referred to as a semiautomatic welding process


A bolted bonnet, or cover of a valve, is fastened (by bolts) to the valve body to complete the pressure-retaining shell.

RTJ 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.


Positive Material Identification (PMI) 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.


Submerged arc welding (SAW) is a high quality, very high deposition rate welding process, commonly used to join plate.


The wall thickness in piping terms is defined as schedule (SCH or S).

As an example: a pipe NPS 2 - S40 has a wall thickness of 3.91 mm, the same pipe S80 has a wall thickness of 5.54 mm etc..

For more information about Wall Thickness and Schedule see mainmenu "Pipes > NPS and Schedule"


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.


The flat face flange has a gasket surface in the same plane as the bolting circle face. Flat Face does not feature the raised face of heavy duty flanges such as ANSI B 16.5 for example.

Applications using flat face flanges are frequently those in which the mating flange or flanged fitting is made from a casting.


Post Weld Heat Treatment (PWHT) 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.


Shielded Metal Arc Welding (SMAW) is frequently referred to as stick or covered electrode welding. Stick welding is among the most widely used welding processes


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

see also AFC - Approved For Construction


GAMW is an abbreviation of

Gas Metal Arc Welding


A bill of materials is a detailed item by item tabulated list of the project requirements for piping.

It specifies the required item by the reference grade and standard to which it must be made, by the size and its rating. The information on this table is entirely extracted from the material take-off documents.

see also MTO - Material Take-Off


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.


A final material take-off is a accurate list of ALL the required piping items of a project in tabulated form.

see also BOM - Bill Of Materials


Approved for construction means, that eg a piping isometric meets all requirements, and that AFTER release the prefab can begin.

see also RFC - Released For Construction

Info from wermac of Piping World.

19 Januari 2011

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