Pipe Class Ratings vs. Pressure Numbers (PN)
Pressure numbers (PN) vs. flange class designations.
Piping Class Ratings based on the ASME B16.5 - Pipe Flanges and Flanged Fittings: NPS 1/2 through NPS 24 Metric/Inch Standard - class and the corresponding ISO 7005 PN (Pression Nominal*) ratings:
| Flange Class | 150 | 300 | 400 | 600 | 900 | 1500 | 2500 |
| Flange Pressure Nominal (PN) | 20 | 50 | 68 | 110 | 150 | 260 | 420 |
* "Pression Nominal" is the French equivalent of Pressure Nominal
"Pression Nominal" is the rating designator followed by a designation number indicating the approximate pressure rating in bars.
- 1 bar = 1x105 Pa (N/m2) = 0.1 N/mm2 = 10,197 kp/m2 = 10.20 m H2O = 0.98692 atm = 14.5038 psi (lbf/in2)
PN ratings do not provide a proportional relationship between different PN numbers, whereas class numbers do. Class numbers are therefore recommended before PN ratings.
Note! The piping rating must follow the pressure-temperature rating of the weakest pressure containing item in the system.
Related Topics
-
Piping Codes and Standards
Piping and tubes codes and standards - ASME, ANSI, ASTM, AGA, API, AWWA, BS, ISO, DIN and more. -
Pressure Ratings of Pipes and Fittings
Pressure ratings of pipes and tubes and their fittings - carbon steel , stainless steel, plastic, copper and more.
Related Documents
-
Aluminum Tubing - Allowable Pressures
Allowable pressure for aluminum tubes. -
ANSI - American National Standards Institute
ANSI provides a forum for development of American national standards. -
ASME - American Society of Mechanical Engineers
ASME is one of the leading organizations in the world developing codes and standards. -
ASME B31 Pressure Piping - Overview
A survey of one of the most important pressure pipe codes - ASME B31, earlier known as ANSI B31. -
ASTM Flanges - Hydrostatic Test Pressures
Flanged fittings and required hydrostatic test pressure. -
Bolt Stretching and Tensile Stress
Tensile stress and Hooke's Law. -
Bronze Flanges - ASME/ANSI 150 lb
Flange diameters, thickness, bolt circles, numbers and diameters of bolts for ASME/ANSI B16.15 - Cast Bronze Threaded Fittings - 150 lb Bronze flanges with plain faces. -
Bronze Flanges - ASME/ANSI 300 lb
Flange diameters, thickness, bolt circles, numbers and diameter of bolts for ASME/ANSI B16.15 - Cast Bronze Threaded Fittings - 300 lb Bronze - Flanges with plain faces. -
Carbon and Stainless Steel Flanges - ASME/ANSI Class 150
ASME/ANSI B16.5-1996 Pipe Flanges and Flanged Fittings - Class 150 Flanges - outside and inside diameters, bolt circles, numbers and diameters of bolts. -
Carbon and Stainless Steel Flanges - ASME/ANSI Class 900
ASME/ANSI B16.5-1996 Pipe Flanges and Flanged Fittings - Class 900 Flanges - outside and inside diameters, bolt circles, numbers and diameters of bolts. -
Carbon Steel Flanges - Pressure and Temperature Ratings
Maximum ratings for flanges conforming to ISO Standard 2229 dimensions and material specification AST-A-105. -
Carbon Steel Pipes - Pressure and Temperature Ratings, Imperial Units
Pressure (psig) and temperature (deg F) ratings for A-53 B and A-106 B, A333, A334 and API 5L carbon steel pipes - temperatures ranging 100 degF - 700 degF. -
Carbon Steel Pipes - Pressure and Temperature Ratings, Metric Units
Pressure (kPa)> and temperature (degC) ratings of ASTM A-106, API 5L and ASTM A-53 Seamless Carbon Steel Pipes - temperatures ranging -29 degC - 450 degC. -
Cast Iron Threaded Pipe Fittings - Working Pressures vs. Temperature
Maximum working pressures for cast iron threaded pipe fittings according ANSI B16.4. -
Forged Steel Flanges - Stud Charts
Number of studs, diameter and length for ANSI forged steel flanges ranging class 150 to 1500. -
Malleable Iron Threaded Fittings - Pressure vs. Temperature Rating
ASME/ANSI B16.3 Malleable Iron Threaded Fittings - Pressure and Temperature Ratings. -
NPS - 'Nominal Pipe Size' and DN - 'Diametre Nominal'
The size of pipes, fittings, flanges and valves are often given in inches as NPS - Nominal Pipe Size, or in metric units as DN - 'Diametre Nominal'. -
Pipe Flanges and Gaskets - Dimensions
Gasket dimensions according ASME B16.5 Pipe Flanges and Flange Fittings. -
Schedule - Terminology
Introduction to the schedule terminology of pipes.
