Glossary Of Terms

Use this glossary to learn some of the most common OCTG and Line Pipe terms.

 

A

 

ALLOY STEEL

Steel is considered an alloy when it contains alloying elements of at least 1.65% manganese, .60% copper, and .60% silicon.

ANNEALING

Heating to a temperature above or below the critical range, followed by controlled cooling to below the critical range.  This process changes the metal’s microstructure.  Depending on the process, this can harden or soften the metal, as well as remove stresses, and change other properties.

API

American Petroleum Institute.  A trade association founded in 1919.  Developed standardized testing of drill equipment.  API licenses the use of its logo to companies willing to adhere to API minimum standards or specifications.  Works closely with ISO

ANSI

American National Standards Institute

ASME

American Society of Mechanical Engineers

ASTM

American Society for Testing Materials

 

B

 

BARLOW’S FORMULA

An equation which shows the relationship of internal pressure to allowable stress, nominal thickness, and diameter.

BEND TEST

Tests used to determine ductility of steel subjected to bending.

BEVEL

The angle between the prepared edge of the end of a pipe and the plane perpendicular to the surface.

BILLET

A semifinished round or square solid that has been hot worked.

BRUSH ROLL & SPRAY

A cleaning process by which used or surplus pipe has the OD brushed to remove any scale, rolled in order to cover all surface area, and sprayed with a protective lacquer coating.

BURST TEST

A destructive test by which hydraulic pressure is used to determine actual yield strength.

 

C

 

CARBON STEEL

A metal alloy formed by combining iron and carbon.

CHARPY TEST

The method used to measure the amount of energy absorbed by a notched specimen during fracture as a result of an impact load.

COATING

The process of covering the steel with another material to protect against corrosion

COUPLING

Threaded sleeve used to connect two lengths of pipe

CONTINUOUS WELD

Method of pipe production in which the material is furnace welded in continuous lengths, and later cut to length.  Normally seen for sizes ½” OD to 4” OD

CRA

Corrosion Resistant Alloys.

 

D

 

DRL

Double Random Length.  35 feet minimum average.

DRIFT

The measure of roundness or eccentricity of the inside wall of pipe

 

E

 

EDDY CURRENT TESTING

Nondestructive method of testing where eddy current flow is included in the tested object.  Changes in flow of current are analyzed.

ERW

Electric Resistance Weld.  Pipe manufactured by rolling steel into the desired tube size and welding the seam.  Usually for sizes 2 3/8” OD to 22” OD

 

F

 

FLD

Full Length Drift.

FRACTURE TEST

A test by which a piece of metal is broken to examine the fracture and determine the crystalline structure or carbon content.

FULL BODY NORMALIZING

Heating the pipe past the critical point, and cooling at room temperature.  This process helps create uniform hardness.

 

G

 

GALVANIZING

The process of coating iron or steel in a protective layer of zinc

GRADE

Used to identify the different types of steel based on carbon content or other properties.

 

H

 

HARDNESS

Resistance of a metal to plastic deformation, usually indentation.  Sometimes refers to stiffness or temper.

HEAT ANALYSIS

The chemical analysis representative of a heat of steel, determined by analyzing a test sample obtained during the pouring of the steel.

HEAT TREATMENT

Combination of heating and cooling applied to metals or alloys in their solid state to create a desired property.

HIC TEST

Hydrogen Induced Cracking.  Used to evaluate the resistance of pipeline and pressure vessel plate steel to cracking caused by hydrogen absorption from aqueous sulfide corrosion.

HIGH FREQUENCY WELDING

Welding technique used during ERW.

HYDROSTATIC TEST

Mill test where the pipe ends are sealed, and high pressure water is introduced at predetermined pressures.

 

I

 

ID

Internal diameter, the measured size of the only hole you should find in your pipe.

IMPACT TEST

Test to determine behavior of materials when subjected to high rates of loading, typically from bending, tension, or torsion.

ISO

International Organization for Standardization

 

J

 

Joint

A single piece of Pipe.  Typically used as a substitute to Footage in reference to QTY.

 

K

 

KSI

Kilopounds per square inch.  A measurement used to define Tensile and Yield strength, equivalent to 1,000 lbs.  Example: N-80 grade tubing has 80 KSI minimum yield, 110 KSI max yield, and 100 KSI minimum tensile strength.

 

L

 

LINE PIPE

Manufactured for the conveyance of oil and gas in transmission lines, distribution main lines, and offshore pipeline systems.

 

M

 

MAGNETIC PARTICLE INSPECTION

Testing method which utilizes iron powder and electromagnetic current to detect cracks and other problems on or near the surface of ferromagnetic materials.  Nondestructive.

MAOP

Maximum Allowable Operations Pressure.

METALLURGY

The science related to extraction of metals from ore and the adaptation and/or application of the metals.

MILL FINISH

Surface finish produced on sheet and plate steel, with characteristics of the ground finish on rolls used to fabrication

 

N

 

NDE

Non Destructive Examination.

NOMINAL

Standard pipe size designation

NORMALIZING

Heating material to at least 100f above the critical temperature and cooling over time at room temperature.  This process recrystallizes and refines the grain structure, as well as provides uniformity of hardness to the product.

 

O

 

OCTG

Oil Country Tubular Goods.

OD

Outer Diameter.  This is the first term generally used when describing pipe.

 

P

 

PE

Plain End.  Pipe that has not yet been threaded.

PESC

Plain End Square Cut

PICKLING

The process by which surface oxide and scale is removed by an acid wash process.  Sulfuric acid is typically used for carbon and low-alloy steels.

PILING

Steel, timber, or concrete piles set closely together to resist lateral pressure from land or water.

PLATE

Carbon steel plate or flat rolled finished products

PSI

Pounds per Square Inch.  Used in measuring pressure.

PSL

Product Specification Level

PPF

Pounds Per Foot.  A typical unit of measure to express the wall thickness and weight of a length of pipe.  Pounds Per Foot is calculated as 10.69 * (OD – Wall Thickness) * Wall Thickness = PPF

 

Q

 

QTY

Quantity.

QUENCHING

Heating the material and cooling rapidly in air or liquid to produce a desired crystalline structure.

 

R

 

RL

Random length

 

S

 

SC

Square Cut

SCALE

Iron oxide (rust) that builds up on the surface of steel

SCHEDULE

ANSI numbers used to define pipe wall thickness

SMLS

Seamless.  Pipe which has been extruded from a billet, rather than rolled and ERW from a coiled sheet.

SMTS

Specified Minimum Tensile Strength

SMYS

Specified Minimum Yield Strength

SRL

Single Random Length

STENCIL

Identifying information painted onto the OD of pipe

STD

Standard

STRUCTURAL STEEL

Either mill new pipe that has been shaped to specification, or used OCTG which is still structurally sound and can be cut and welded to the desired shape.

SURFACE INSPECTION

Testing done to determine if the pipe has any external defects such as bad welds or burns.

 

T

 

TBE

Thread Both Ends

T&C

Threaded and Coupled

TENSILE STRENGTH

The value obtained by dividing the maximum load observed during tensile straining until breakage, by the specimen cross-sectional area prior to straining.

TOUGHNESS

The property of absorbing energy before fracturing

TRL

Triple Random Length

 

U

 

UT

Ultrasonic Testing.  A nondestructive method of detecting, locating, and measuring both surface and subsurface defects in metals using high-frequency sound.

 

V

 

W

 

WALL

The thickness of the pipe body

 

X

 

Y

 

Z