Direct answer · Updated 25 October 2026
What is PN16 pressure rating in kg/cm², and what is Class 800 or Class 300 in bar?
PN16 = 16 bar = 16.3 kg/cm² = 232 psi; PN10 = 10.2 kg/cm². ASME class ratings for carbon steel (WCB / A105) at ambient temperature are: Class 150 = 19.6 bar (20.0 kg/cm²); Class 300 = 51.1 bar (52.1 kg/cm²); Class 600 = 102.1 bar; Class 800 = 136.2 bar (138.9 kg/cm², 1,975 psi); Class 1500 = 255.3 bar. Ratings fall as temperature rises.
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Valve Pressure Rating Chart: PN and ASME Class in Bar, kg/cm² and psi
Quick conversion tables for PN and ASME class valve ratings, with carbon steel and stainless steel values, PN–Class equivalents and test pressures.
PN rating in bar, kg/cm² and psi
The PN number is the nominal pressure in bar at 20°C for the reference material. Because 1 bar = 1.0197 kg/cm², the kg/cm² value is about 2% higher than the PN number. The table gives the conversion; the allowable pressure falls at higher temperature, depending on the body material.
ASME Class pressure rating in bar, kg/cm² and psi
ASME class numbers are not pressures. Class 150 does not mean 150 psi: a WCB Class 150 valve is rated 19.6 bar (285 psi) at ambient temperature. The values below are the maximum working pressures at −29 to 38°C from ASME B16.34 (standard class) for carbon steel (Group 1.1: WCB, A105) and SS316 (Group 2.2: CF8M, F316).
*Class 800 is an intermediate class used for small-bore forged steel gate, globe and check valves to API 602 (½" to 2", socket weld or threaded). It is not a flange class; Class 800 valves are normally socket weld or screwed.
PN vs ASME Class: approximate equivalents
PN flanges (EN 1092-1) and ASME flanges (B16.5) have different bolt circles and bolt counts. Always state the flange standard in the enquiry; a PN16 valve will not bolt to a Class 150 flange.
How temperature changes the rating
Pressure ratings fall as temperature rises. For example, a WCB Class 150 valve is 19.6 bar at 38°C but about 13.8 bar at 200°C and 10.2 bar at 300°C; a Class 300 WCB valve drops from 51.1 bar to about 43.8 bar at 200°C. For steam and hot oil service, check the rating at the design temperature, not at ambient. See the full pressure-temperature rating tables.
Test pressures
Shell hydrostatic test pressure is 1.5 times the 38°C rating, and the high-pressure seat test is 1.1 times the rating (API 598 / ASME B16.34). For WCB Class 150 this is about 30 bar shell and 22 bar seat. Full tables are in the valve testing pressure chart.
What to send with your enquiry
- Valve type, size and quantity
- Pressure rating (PN or ASME class) and flange standard
- Design pressure and design temperature
- Body and trim material
- End connection: flanged, butt weld, socket weld, screwed
Send the line list or datasheet to info@supremevalves.in or use the quote builder. Technical clarifications and a priced offer follow within one working day for standard items.
Related products and guides
Pressure-temperature ratings
Full ASME B16.34 P-T tables.
ASME B16.34 pressure rating
Standard class, special class and material groups.
Valve testing pressure chart
API 598 shell and seat test pressures.
Class 150 / 300 / 600 guide
Choosing the right pressure class.
Pressure class selector tool
Pick the class for your design conditions.
Forged steel Class 800 valves
API 602 gate, globe and check valves.
Valve class FAQs
Common questions on valve classes.
WCB valves
Cast steel valves Class 150 to 2500.
Frequently asked questions
What is PN16 pressure rating in kg/cm²?
PN16 is 16 bar, which equals 16.3 kg/cm² or about 232 psi, at 20°C for the reference material.
What is PN10 pressure rating in kg/cm²?
PN10 is 10 bar, which equals 10.2 kg/cm² or about 145 psi.
What is Class 800 pressure rating in bar?
For carbon steel (A105) Class 800 is 136.2 bar (138.9 kg/cm², 1,975 psi) at −29 to 38°C. Class 800 is used for small-bore forged valves to API 602.
What is Class 300 pressure rating in kg/cm²?
For carbon steel (WCB / A105) Class 300 is 51.1 bar, which is 52.1 kg/cm² or 740 psi at ambient temperature. For SS316 it is 49.6 bar (50.6 kg/cm²).
Is Class 150 the same as 150 psi?
No. Class 150 carbon steel is rated 285 psi (19.6 bar) at ambient temperature, falling to about 200 psi at 200°C. The class number is a designation, not a pressure.
Is PN16 the same as Class 150?
They are close in pressure, but PN16 (EN 1092) and Class 150 (ASME B16.5) flanges have different dimensions and drilling and cannot be bolted together.
About this page: Written by the Supreme Valves India engineering team, Ahmedabad (supplying industrial valves since 1986). Last reviewed 25 October 2026. Figures are typical values for selection; the governing values are those in the referenced standard and on the approved datasheet for each order. Entity facts: Supreme Valves brand facts.
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