All Terms Made Easy

Abbreviations and terminologies can be confusing and hard to define. In order to make your search easier, we gathered many of the acronyms, abbreviations and terms that pertain to our industry—and put them in one place for easy reference.

AARH - Arithmetic Average Roughness Height
AISI - American Iron and Steel Institute
API - American Petroleum Institute
ANSI - American National Standards Institute, Inc.
ASME - American Society of Mechanical Engineers
ASTM - American Society for Testing and Materials
AWS - American Welding Society
BB - Bolted Bonnet
BHN - Brinell Hardness Number
Blind Flange - A Flange with no flow way bore, used to provide a pressure-tight closure of a flanged opening.
Btu - British Thermal Unit
BWE - Butt Weld Ends
C or Cel - Celsius degrees
CI - Cast Iron
CI - Chlorine Institute CR 13 - 13% Chromium Stainless Steel
CRES - Corrosion Resistant Steel
C(v) - The number of U.S. gallons per minute of water at 70 degrees Fahrenheit which will flow through a valve at a pressure drop of one psi.
CWP - Cold Working Pressure
DN - Diameter Nominal (Metric)
ELL - Elbow

FAS - Free Alongside Steamer
F or FAH - Fahrenheit degrees
F & D - Faced and Drilled
FF - Flat Face
FHF - Full Hard Faced
FLG - Flanged
FOB - Free on Board
FTTG - Fitting
G - Gas
gpm - Gallon per Minute
HF - Hard Faced
HW - Handwheel
IBBM - Iron Body Bronze Mounted
ID - Inside Diameter
INT - Integral
IPS - Iron Pipe Size
ISRS - Inside Screw Rising Stem
ISNRS - Inside Screw Non. Rising Stem
Kg - Kilograms
km - Kilometers
LH - Left Hand
MAV - Motor Actuated Valve
mm - Millimeter
MOV - see MAV
MSS - Manufacturers Standardization Society of the Valve & Fitting Industry
NACE - National Association of Corrosion Engineers

NPS - Nominal Pipe Size
NPT - National Standard Pipe Thread Taper
NRS - Non Rising Stem
OD - Outside Diameter
One-Piece Stem - An inseparable Stem and Disc made from one piece of metal.
OS&Y - Outside Screw & Yoke
OWG - Oil, Water & Gas
PN - Pressure Nominal (Metric)
Psi - Pounds per square inch
Psia - Pounds per square inch absolute
Psig - Pounds per square inch gage
P-T - Pressure-Temperature
Rc - Rockwell “C”
RF - Raised Face
RH - Right Hand
RMS - Root Mean Square Roughness Height
RS - Rising Stem
RTJ - Ring-Type Joint
S - Steam
SAE - Society of Automotive Engineers
SC - Swing Check Valve
Sch. or Sched. - Schedule (Pipe Wall Thickness)
SCFM - Standard Cubic Feet per Minute
Screw Bonnet - Body and Bonnet Threaded Together

SE - Screwed Ends
Seal Weld - Threaded Joint Back Welded for Seal
SS - Stainless Steel
Stem Nut - Operating Nut
Stuffing Box - Packing Chamber
STD - Standard Wall Thickness
Stop Check - A Check valve in which the closure member can be mechanically closed
SWE - Socket Weld End
SWP - Steam Working Pressure
T - Tee
Thd. - Threaded
TIR - Total Indicator Reading
UB - Union Bonnet
W - Water
Wedge - Gate
WOG - Water, Oil and Gas
WSP - Working Steam Pressure
WWP - Working Water Pressure
XS - Extra Strong Wall Thickness
XXS - Double Extra Strong Wall Thickness
Y - Wye Valve, Fitting or Strainer
Yoke Brushing - Operating Stem Nut
Yoke Nut - Steam Nut

Petro-Valve, Inc
3801 Yale St. Ste. E
Houston, TX 77018
(713) 676-1212