GENERAL

Revised: 07/07/2008

Oilfield Glossary:
Terms and Definitions

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Defined limits placed on the characteristics of materials, products, or services. Visually stated in referenced industry specifications and standards

Reference documentation and/or illustrations that allow comparison of Indications or Discontinuities found during Nondestructive Testing to a standard, for the purpose of acceptance or rejection.

Any flange that will connect between two other flanges that would otherwise not connect. Usually a Double Studded Adapter (DSA), or a Single Studded Adapter (SSA).

A unit of pressure control equipment with a body and two different end connections used to connect together other pieces of equipment that could otherwise not connect. Sometimes used instead of a Double Studded Adapter because at least one of the units to which it connects has a studded flange connection.

Refers to the area of space between the inside diameter of a drilled or cased hole and a secondary string of pipe suspended inside this space.

American National Standards Institute. An organization formerly known by the name American Standards Association (ASA). This organization sets standards for the ANSI B16.5 Blind, Weld Neck, and Threaded Flanges commonly used in refineries and process industries.

For information comparing "ANSI" and "API" Flanges, see A Brief History of Well Head Flanges.

American Petroleum Institute. The organization that develops and publishes API specification documents.

A registered trademark of the American Petroleum Institute (API). Qualified licensed manufacturers may apply the API Monogram along with their license number, as a mark onto a product or equipment that meets the requirements of API published specifications.

Also, ISO 10423; The American Petroleum Institute publication that serves as the industry Specification for Wellhead and Christmas Tree Equipment. Those companies granted a license from API may apply an API Monogram mark, along with their license number, to products which they have made in compliance with this specification.

Also, ISO 13533; The American Petroleum Institute publication that serves as the industry Specification for Drill Through Equipment. Those companies granted a license from API may apply an API Monogram mark, along with their license number, to products which they have made in compliance with this specification.

The American Petroleum Institute publication That serves as the industry Specification for Subsea Wellhead and Christmas Tree Equipment. Those companies granted a license from API may apply an API Monogram mark, along with their license number, to products which they have made in compliance with this specification.

See Connector Axial Alignment

Also, Fluid Balance; That condition when the fluid Head in a well bore produces sufficient pressure inside the well bore to equal the pressure of the production zone and stop the outflow of fluid or gas from that zone.

An upward pipe extension above the uppermost BOP, used to discharge returning drilling mud to the shakers, separators, and pits during drilling operations. The "Bell" term derives from the bell mouth usually fabricated on its upper end, See Flange, Bell Nipple.

An Abbreviation for Brinell Hardness Number. Now abbreviated HBW.

An Abbreviation for Bottom Hole Test Adapter. See Top Connector

For Choke Manifolds, see Blast Spool. For tubing strings in wells, the term Blast Joint applies to a piece of heavy walled tubing, run in the tubing string and positioned across from a perforated interval to resist external erosion caused by high velocity production fluid coming from that zone, thus prolonging the life of the completion.

For Choke Manifolds, this term applies to a specially constructed spool attached directly to the outlet connection of a Drilling Choke where high velocity fluid erosion may occur. Manifold designers build this spool with the maximum practical wall thickness and sometimes specify an erosion resistant liner for this spool.

A unit of equipment, installed singularly or as a part of an assembly, attached to the Wellhead to control and/or contain well pressure occurring inside the Casing during Drilling, Workover, or Snubbing operations.

An Abbreviation for Blowout Preventer.

The portion of a unit of pressure control equipment between separated end connections.

The theoretical circle inscribed by the center point of a series of holes, drilled equally spaced, near the mid circumference of a flange.

That energy achieved by applying Torque to nuts on bolts providing the compressive force necessary to hold connections in contact under pressure or load.

That rotational force applied to nuts on stud bolts to tighten and apply Tension to the bolts in order to hold flanges or other connections in Make-up. This force is usually expressed in Foot Pounds (FT/LBS). See Torque Wrench.

See Top Connector.

Also Break Apart; The act of disconnecting joined flanges or other Connectors.

Now abbreviated HBW. A designation of hardness, usually of steel, performed by pressing a 10 mm spherical tungsten carbide ball against a clean prepared surface using a 3000 Kilogram force, producing an impression, measured and given a special numerical value. This numerical value relates to steel tensile strength. API Spec 6A specifies minimum Brinell Hardness requirements for different material designations. NACE Standard MR0175 references maximum hardness in determining steel’s suitability for use in H2S Service.

Also, a Header; Typically, a fabricated pressure vessel with multiple inlets and outlets, used to contain and direct the discharge from Chokes in a Manifold system. An alternate method of buffer system construction allows the use of non-welded components.

The completed weld made in a Butt Weld Joint.

This term describes a form of weld joint having specially prepared surfaces that makes a Full Penetration Weld possible, usually by leaving a small gap between the adjacent pieces that deposited weld metal will bridge, fill, and close.

See 6 BX

An iron based metal with only carbon and manganese deliberately added to specific limits. Other elements residual, except for small quantities added for deoxidization or to control the effects of sulfur.

Pipe used to line the bore hole of a well.

A single unit of well control equipment (usually flanged) attached to the upper end of surface casing, allowing the attachment of Blowout Preventers during drilling, and later suspending and sealing a secondary string of casing set inside.

A single unit of well control equipment attached above the Casing Head, used to suspend and seal a secondary casing string.

Steel formed by pouring molten steel  into a mold to produce a desired near finished shape after solidification and cooling.

A shape made from cast steel. The term casting may also apply to the process of pouring liquid steel into a mold.

See Qualified Welder.

A test performed at a specified temperature by swinging a calibrated falling pendulum (hammer) fracturing (breaking) a specifically configured Specimen of Material and  measuring the force required, usually expressed in foot pounds.

The chemical composition of Material. The expression of the elemental composition of material by percentage of weight for each measured chemical element.

Also, Choke Valve; A unit of pressure control equipment used to restrict and regulate the flow of well fluids to maintain a desired pressure and flow rate. Chokes have hardened internal expendable parts specifically designed to resist erosion caused by high pressure, high velocity fluid. Often used as part of a Choke Manifold (also see Drilling Choke) or Christmas Tree.

An assembly of valves, Fittings and Chokes arranged to regulate and control the flow of high pressure fluid from a well bore.

An assembly of equipment topping off the Wellhead, including valves, fittings, Chokes, etc. used to regulate and control the flow of oil or gas during normal well production.

The condition of bringing metal surfaces of differing hardness so tightly together that the softer surface deforms to match the harder surface exactly in shape and finish. See Intimate Contact.

A uniquely configured Ring Gasket that allows two flanges with ring grooves of different Pitch Diameters to join and seal when Made-up.

Those special bolts made to join flanges of different Working Pressures, having a different diameter on each end to correspond with the bolt holes in each respective flange. See Cross Over Connections for a full explanation.

A specially configured Ring Gasket that allows two flanges with Ring Grooves of different width and depth but the same pitch diameter to join and seal when Made-up.

For Wellhead application, the part of pressure containing / pressure controlling equipment that allows a mechanical joint that can provide a pressure seal: Flange, Hub, Union, etc., that does not seal on a thread.

Alignment to within specified tolerances of the connector centerline, to the centerline of the connector at the opposite end of the equipment unit.

Any flange, hub, or Other End Connector, not integral to a body of an identified piece of equipment.

A measure of the connector face (or plane) with respect to the connector face at the opposite end of the equipment unit.

Ring Grooves lined with material resistant to Metal Loss Corrosion. This material is either CRA or an austenitic stainless steel.

Nonferrous alloys where any one or the sum of the specified amount of the following alloy elements exceeds 50%: titanium, nickel, cobalt, chromium, and molybdenum. A Material sometimes used in critical service applications for flanges, bodies, bonnets and other components. Also frequently used as a weld metal overlay for ring grooves to prevent Rust damage between connection make-ups.

Ferrous or nonferrous alloys which are more corrosion resistant than low alloy steels. This term includes CRA's, duplex, and stainless steels.

Any Fitting with four connections in the same plane with two of these connections forming an in-line Run.  Crosses may have more than four connections.

Now obsolete or withdrawn ring groove specifications that allowed face to face contact on Made-up hubs or flanges when using RX ring gaskets. See SR ring grooves.

Industry standard products or equipment that the issuing standards organization has announced it will no longer include in its published specifications.

A location, internal or external, where the structural nature of Material (or a weldment) has an interruption of its normal or continuous regularity. A place where metals exhibit some mechanical, physical, or metallurgical irregularity that requires evaluation by reference to Acceptance Criteria.

A specialized Annular Blowout Preventer used, in conjunction with large diameter flow valves, to close and divert shallow gas encountered during drilling operations.

Also, Double Extra Heavy; A designation of pipe with a wall thickness twice that of Extra Strong Pipe. See Carbon Steel Pipe Dimensions and Weights for commonly available pipe sizes.

A flange with a through bore and a ring groove on each side, drilled and tapped bolt circles on both sides and Tap End Studs complete with nuts installed on both sides. Usually the two sides are different in size and/or pressure rating. Usually used to adapt between different flange end connections that would otherwise not connect.

A gauge of special dimensions used to pass through the Run of pressure control equipment to demonstrate that the Run bore will pass working tools. Also, the act of passing this gauge through the bore.

The process of making a bored well hole to test for and, if encountered in commercial quantities, produce oil and/or gas.

A Choke  specifically designated by its manufacturer as suitable for drilling service, used as part of a Choke Manifold.

The entire collection of machinery and equipment brought together as a unit and used to drill and set Casing for an oil or gas well. An operating drilling rig includes Blowout Preventers and drill pipe.

Also, Mud Cross; A unit of equipment used with Blowout Preventers to space pieces of equipment apart and provide outlets to attach lines extending to Choke and Kill Manifolds.

An abbreviation for Double Studded Adapter.

See Segmented Flanges.

A property of Material that allows it to yield or "bend before breaking."  Technically expressed by measurement records of Elongation and Reduction of Area determined as the result of a Tensile Test.

That amount that a Material Specimen will stretch before fracture (separation). Usually expressed as a percentage of the original length.

That connection on either end of the Run (through the central bore) of pressure control equipment.

Also, Extra Heavy; A designation of pipe wall thickness specified  in API Spec 5L in addition to many other pipe  wall thicknesses. See Carbon Steel Pipe Dimensions and Weights for commonly available pipe sizes.

An abbreviation for 15,000 pounds per square inch (psi) Maximum Service Pressure.

That equipment, made with 2 or more pieces of steel joined together by welding. Such fabricated equipment may contain pressure or provide structural support for pressure containing equipment. See One Piece Construction for comparison.

A term, preceded by an inch size, describing a specific union design widely used on flange by union adapters.

A term, preceded by an inch size, describing a specific union design widely used on flange by union adapters

A unit of pressure containing equipment designed to fit between other equipment for the purpose of adapting or arranging that other equipment to facilitate pressure control. See Tee or Cross.

See Segmented Flanges.

An abbreviation for 5,000 pounds per square inch (psi) Maximum Service Pressure.

A single disc or a protruding disc extension on a body with holes to accept bolts or with holes drilled and  tapped into its surface with Tap End Studs installed, with a sealing means, used to join pressure containing equipment.

A flange specified in American National Standards Institute published standards.

A flange specified, now or in the past, in American Petroleum Institute published standards.

Any flange that will connect between two other flanges that would otherwise not connect. Usually a Double Studded Adapter (DSA), or a Single Studded Adapter (SSA).

The Flange attached to the Bell Nipple used to secure it to the top of the uppermost BOP.

A flange with no center opening, designed to close off an outlet or end connection.

A flange with two Bolt Circles drilled through, or tapped for studs, so that it may join another flange of a lower working pressure.

A flange integral with a body (e.g. spacer spool, etc.) with an opposite integral connection.

A flange, usually made as a spacer with a ring groove on both sides to go between two other flanges, with special tapped connections through its side (O.D.), to facilitate the injection or sampling of fluid or the measurement of pressure.

A flange made as part of a Body or attached to a body by welding. The flange Material conforms to specification requirements for integral flanges.

See Connector, Loose

A flange specified in Manufacturing Standardization Society, Standard Practice SP-44. Used by manufact- urers of Diverters in 30" 500 and 30" 1000 psi working pressure.

A flange connection with through bolt holes. An open face flange will mate with another open face flange or with a Studded Face Flange.

An integral flange connected to a Body (e.g. Tee,) usually at 90 degrees from the end connection.

A flange that utilizes a Ring Gasket has the designation "Ring Type Joint", abbreviated "RTJ" in flange standards other than API Spec. 6A. All API Spec. 6A flanges have "Ring Type Joint" sealing surfaces.

An out of date term, applied in the past to API flanges now described in terms of working pressure.

A flange, made with a ring joint connection on both sides, to go between two other flanges to space them apart for some special purpose.

A flange connection with the bolt circles drilled and tapped into its face so as to accept Tap End Studs  (e.g. the connections on a Studded Cross). A studded face flange will mate only with an Open Face Flange.

A Blind Flange, usually with a lead filled cavity, used to cushion and minimize the erosion of high velocity abrasive fluid.

A flange with a tapped port in its center or side to allow application of pressure or attachment of a gauge.

A flange with an internal or external  thread opposite its Ring Groove side to mate with standard threaded pipe.

A flange with a butt weld neck for welding attachment to pipe or tubing. Material may vary from that required for Integral Flanges in order to facilitate field welding.

Any line of  pipe, that contains and controls the flow of  fluid.

A term usually used to express the amount of rotational force (Torque) applied to nuts on stud bolts. "One Foot Pound" equals the force of one pound of pull on a wrench with a handle that extends 12 inches from the center axis of a bolt and nut upon which the force acts. See Bolt Torque and Torque Wrench.

Steel, plastically deformed and shaped, usually when hot, using compressive force to breakup and close any internal Discontinuities.

See Forged Steel.  Also, the act of using compressive equipment (presses or hammers) to plastically deform steel into a desired shape.

A weld performed on a prepared joint between adjacent pieces, the weld metal extending through the entire wall.

A low alloy steel containing molybdenum and chromium as strengthening agents. The carbon content is nominally 0.30% and with this relatively low carbon content the alloy is excellent from the fusion weldability standpoint. The alloy can be hardened by heat treatment.

One of the chromium, molybdenum, manganese low alloy steels noted for toughness, good torsional strength and good fatigue strength after heat treatment. The carbon content of 0.40% makes this steel less easily welded than 4130.

An API Spec 6A abbreviation for 45,000 psi, minimum yield strength Material.

Also, Gauge;  A preset device for determining the relative size or shape of an object compared to a standard (e.g. a Drift).  The act of using a gage to compare or confirm a size or shape.  A device to measure pressure within a pressure containing or controlling system.

See Gage.

An abbreviation for the chemical Hydrogen Sulfide.

Short for Hydrogen Sulfide Service (HSS). A term used to designate that equipment material specifications meet the requirements of NACE Standard MR0175, for use in controlling fluid containing partial pressure (some percentage) of Hydrogen Sulfide.

Also, Wing Unions; Connectors that allow quick make-up and break-out of pipe and fittings used primarily in temporary flow-lines. Any connected Hammer Union consists of 3 pieces.

1) A male connector with a spherical sealing surface.

2) A female connector with a tapered sealing surface and external Acme threads.

3) A wing nut with internal Acme threads that fits over the male connector and screws onto the female connector holding the two connectors together, achieving a seal.

Some Hammer Unions contain an elastomeric secondary seal.

A box end wrench with a shortened heavy handle having an elongated square shaped end. Designed to withstand heavy striking with a sledge hammer to tighten or loosen nuts on stud bolts.

A measured factor that reasonably predicts the amount metal will resist abrasion and bending, as well as indicating Ultimate Strength. Most commonly expressed as Brinell Hardness and Rockwell Hardness. ASTM E 140 provides a guide for comparing hardness determined by different methods and expressed on different scales.

The standing column of fluid in a well bore.  The measure of fluid pressure at the bottom of a column of fluid in a well bore or in any vertical fluid containing pipe or system.

See Buffer Chamber.

That part of the base metal formed as a narrow band immediately adjacent to deposited weld metal, affected by welding heat input but not melted.

Heating and cooling metallic Material in such a way as to produce selected and intended conditions and properties in the material. This process affects Tensile Strength, Yield Strength, Elongation, Reduction of Area, and toughness (usually measured as Impact Strength).

Abbreviation for Brinell Hardness.

(Sometimes RB) An abbreviation for Rockwell Hardness measured on the B scale. The abbreviation usually appears after a number, e.g. 83 HRB. See: Rockwell B Hardness.

(Sometimes RC) An abbreviation for Rockwell Hardness measured on the C scale. The abbreviation usually appears after a number, e.g. 22 HRC. See: Rockwell C Hardness.

Also, Hydrostatic Test; a pressure test conducted by pumping a fluid (usually water) into a closed vessel or equipment system until the pressure reaches a specific level. The test consists of holding this pressure for a specific period of time without observed leaks or pressure decline on the indicating instrument.

The chemical commonly abbreviated H₂S. This deadly poison also has a destructive effect on high strength low alloy steels when the hardness of these steels exceed a hardness of 22 Rockwell C.

An abbreviation for Inside Diameter.

The amount of energy required to fracture (break) a Specimen of Material using an impact blow, usually performed at a specified temperature, by means of a Charpy V-Notch Test.

A hardened pointed or rounded contact object used to impress an indentation into the surface of steel (or other metal) parts in order to obtain a Hardness measurement of that part. See HBW, HRC, and HRB.

A term used in magnetic particle testing to identify locations found that require evaluation by references to Acceptance Criteria. See Magnetic Particle Inspection.

Used to describe a form of weld metal deposit, where the weld deposit fills a groove or cavity. Frequently referring to Corrosion Resistant Alloy weld metal deposits in oversize grooves later machined to accept Ring Gaskets.

The condition of bringing metal surfaces of matching shape and finish into contact with such force as to leave no space or gap. See Coining.

Made as a single unit. Usually referring to connectors (Flanges, Hubs, and/or O.E.C.'s) made as part of a body, or joined to a body by welding; the connectors meeting the API specifications for end and outlet connectors.

Abbreviated ISO, this standards organization has taken on a partnership with the American Petroleum Institute to establish equipment  and quality specifications. ISO now issues these specifications and the API adopts them back and further supports these specifications with the API Monogram program.

See:
International Standards Organization

Also, kip; A load of 1000 pounds. See ksi.

The act of pumping heaver fluid into a well bore to bring a well into Balance and stop the outflow from the well.

Abbreviation for one thousand pounds per square inch usually used to indicate material (e.g. steel) strength, sometimes shortened to a suffix K.

This term describes a condition observed in a weld joint when the weld metal does not uniformly continue from the root of the weld to the final cover pass, most often observed at the root of a butt weld.

Pipe generally intended for use in the oil and gas industry for the conveyance of oil and gas under pressure, or for a variety of industrial applications. API Spec 5L and 5LX specify this pipe. For commonly available sizes of line pipe, see Carbon Steel Pipe Dimensions and Weights on this web site.

A method of surface inspection to detect indications not visible to the unaided eye on non-magnetic Materials, or to prove or disprove questionable Magnetic Particle indications.

A liquid penetrant inspection consists of:

• Applying a liquid penetrant colored dye to a clean material surface.

• Allowing time for penetrant to enter any Discontinuities.

• Drying this surface of all liquid visible on the surface.

• Applying a developer coating to the surface to draw out any penetrant that may have entered surface discontinuities.

• Allowing time for the developer to draw out any penetrant to stain the developer coating.

• Observing any colored surface stains and comparison of any indications seen to Acceptance Criteria for acceptance or rejection of the inspected part.

Any assembly of valves and fittings connected to a Blowout Preventer stack to allow pressure equalization and/or bleed down before opening rams. Most commonly used during Snubbing operations.

See Connector, Loose.

See Connector, Loose.

An iron based metal alloy with small amounts of other elements added in specifically measured amounts to produce a desired response to Heat Treatment cycles and achieve intended mechanical properties..

An abbreviation for Line Pipe.

See Top Connector.

See One Piece Construction

Refers to a completed connection after joining flanges or other connectors to achieve a seal.

A non-destructive surface inspection process for ferromagnetic materials (materials that will attract a magnet) performed by magnetizing the material, applying a fine iron powder, either dry or in liquid suspension, to the magnetized surface, and observing the collection of this powder along any breaks in the magnetic field that might represent fractures or other irregularities in the surface. See Indication.

The act of joining flanges or other connectors to achieve a seal.

An assembly of valves and Fittings arranged to regulate and control the flow of high pressure fluid from a well bore. Also see Choke Manifold.

A term used on this web site, and in API documents for pressure control equipment, that identifies the Steel or Corrosion Resistant Alloy used for flanges, bodies, bonnets and other components specified.

Measured aspects of Material used to describe its elastic and inelastic reaction to applied force; These may include Tensile Strength, Yield Strength, Elongation, Reduction of Area, Impact Strength and Hardness.

A basic unit of pressure or tension measurement in the International System of Weights and Measures.
1 MPa - 145 psi,

1 MPa = 1 N/mm2.

(For converter, click here)

That corrosion on the surface of metal that converts the metal to an oxide or otherwise gradually consumes the exposed surface of the metal. Localized metal loss corrosion may appear as "pitting."

An abbreviation for Maximum Service Pressure.

See Drilling Spool.

A document published by the National Association of Corrosion Engineers defining the specific limits of chemistry, hardness and microstructure of Materials used to make equipment to contain or control well production fluids that include hydrogen sulfide.

A term related to "size" or "dimension", indicating a designation only, not the actual measurement. (e.g. 2 inch nominal pipe measures 2-3/8 inches outside diameter and no standard Schedule of the 2 inch pipe has a 2" inside diameter).

Also, Nondestructive Examination or Nondestructive Testing; these terms identify a group of activities using various methods to find, locate, measure, or determine something, without damage, about Material or equipment, that allows an investigator to decide if any identified characteristics or conditions constitute rejectable flaws.

See Zero.

Industry standardized products or equipment that the issuing standards organization has replaced with  updated products or equipment. Manufactured goods the manufacturer has replaced with updated goods.

An abbreviation for Outside Diameter.

An abbreviation for Other End Connector.

Original Equipment Manufacturer. Refers to the company which first designed and built equipment or parts.

This term refers to flanged or hub connection equipment made from a single steel forging. Equipment made this way has no Fabrication (or assembly) welding performed. Equipment manufactured from one piece may often have weld Inlay or Overlay to prevent corrosion damage to Well Wetted surfaces.

Any type  of end (or outlet) connector designed to contain pressure, other than those specified in API Spec 6A. An O.E.C. may have any configuration so long as it meets the design and performance requirements of API Spec 6A. Examples include Union and proprietary Lubricator connectors.

Any connection other than an End Connection on a Run. Used to flow fluid or gas into a Manifold or Choke, or used to pump into, for the purpose of injecting fluid or to Kill a well.

Used to describe a form of weld metal deposit where the weld deposit entirely covers a base metal surface.  Frequently referring to Corrosion Resistant Alloy weld metal deposits over Well Wetted surfaces of pressure control equipment to prevent severe corrosion caused by well fluids.

A single unit of equipment used in a wellhead assembly below the Tubing Head to adapt between flange sizes or pressure ratings and provide a seal around a secondary Casing String.

See Connector Parallelism.

Specifically of a Ring Groove; The theoretical diameter of the ideal mid point (imaginary circular center line) of a ring groove. Most easily determined by measuring carefully from the inside of the ring groove on one side to the outside of the ring groove on the other side (same as measuring from the  centerline on one side to the centerline of the other side). See Measuring Ring Groove Pitch Diameter.

See Stress Relief.

The erosion damage caused by high pressure fluid during an extended leak past a sealing surface.

Also, Working Pressure; the maximum pressure that specific units of equipment should experience in use. API specifies the manufacturer clearly mark the Maximum Service Pressure on each unit of equipment; the equipment pressure rating limited by the lowest pressure connector on the equipment, or the manufacturers design.  For Test Pressure and Working Pressure tests explained, click here.

The hydrostatic pressure applied to equipment to demonstrate the equipment's capacity to hold pressure, A pressure test on existing equipment in the field should equal but not exceed Maximum Service Pressure. The test pressure and procedures for new manufactured equipment, or remanufactured equipment, should comply with that specified by API. For Test Pressure and Working Pressure tests explained, click here.

See Pressure, Maximum Service.

A written document recording all of the testing utilized to prove the validity of the Welding Procedure Specification (WPS) which references it. The PQR contains actual records of the performance of all variable factors called out in the WPS, as well as, the results of all mechanical, volumetric, and surface tests made on samples of the test welds performed to demonstrate that production welds carried out in conformance with the WPS shall meet the specified requirements.

Qualification of a WPS necessarily requires calibrated welding equipment instruments and meters, a record of the calibration and the reference standard, and the date of calibration and frequency performed. Reference ASME SEC. IX QW-200.2. Also see Qualified Welder.

An abbreviation for pounds per square inch to indicate pressure or load.

Product Specification Level, as described in API Spec 6A. The term applies to a tiered progression of increasing testing and inspection requirements for materials and equipment. Other API Specifications include these PSL requirements by reference to API Spec 6A. For more complete information, CLICK HERE.

Product Specification Level 1, references the minimum level of testing and inspection required for material and equipment as specified in API Spec 6A. For more complete information, CLICK HERE.

Product Specification Level 2, references a level of testing and inspection requirements for material and equipment alternate to and in addition to PSL 1 requirements as specified in API Spec 6A. For more complete information, CLICK HERE.

Product Specification Level 3, references a level of testing and inspection requirements for material and equipment alternate to and in addition to PSL 1 and 2 requirements as specified in API Spec 6A. For more complete information, CLICK HERE.

Product Specification Level 3G, references a level of testing and inspection requirements for material and equipment specified in API Spec 6A as PSL 3, adding the requirement of gas testing of completed equipment units. For more complete information, CLICK HERE.

Product Specification Level 4, includes all the testing and inspection requirements described in API Spec 6A for PSL 3G, plus additional restrictions on the material qualification and heat treating, and the prohibition of welding except for overlay/inlay of corrosion resistant material. For more complete information, CLICK HERE.

A person who performs welding in accordance with a Welding Procedure Specification and a sample resulting weld has passed all required visual, mechanical and/or volumetric examinations necessary for acceptance. Maintenance of welder qualification requires that the welder performs welding, using the procedure methods and equipment within specified time periods, and maintains records of this performance. A welder so qualified has qualification to use the same and other WPS's utilizing the same welding process, depositing similar metal, using similar calibrated equipment; with the exception of Corrosion Resistant Alloy inlay, which requires separate specific qualification. Reference ASME SEC. IX ART. III QW-304 and QW-305

A Welding Procedure Specification (WPS) containing a reference to the Procedure Qualification Record (PQR) which demonstrates that the procedure results in the desired properties in the weld metal, heat affected zone and base metal after any post weld heat treatment.

The predicate of quality outcome.

The planning, creation of spec-ifications, choice of inputs, choice of processes (and machines), choice of personnel and training, and continuity of maintenance and management necessary  to produce predictable and desirable product outcomes.

The examination of quality outcome.

The measurement and inspection activities performed at various times during the making of product(s) to ensure that the product(s) mee