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Pressure Class Converter

Convert between ASME pressure classes, PN (DIN/EN) ratings, and JIS K ratings. Find equivalent pressure ratings and working pressures across international standards.

INDICATIVE ONLY — Reference DisclaimerWorking pressures shown are approximate for ASME B16.34 Group 1.1 carbon steel (WCB/A105) at ~38°C (100°F). Actual allowable pressures vary by material group, temperature, and wall thickness. PN ratings and JIS equivalents are approximate — exact equivalence does not exist across standards. Always verify against ASME B16.34, EN 1092, or JIS B2220 for your specific material and temperature. Vajra Industrial Solutions accepts no liability for specification errors based on this table.
ASME ClassPN (DIN/EN)JISbar (38°C)psi (38°C)bar (100°C)psi (100°C)
ASME Class 150PN 20JIS 10K19.628517.7257
ASME Class 300PN 50JIS 20K51.174046.6676
ASME Class 600PN 110JIS 30K / 40K102.1148093.21352
ASME Class 900PN 150JIS 63K153.22220139.82028
ASME Class 1500PN 260JIS 100K255.337052333380
ASME Class 2500PN 420JIS 200K425.56170388.35633

* Values per ASME B16.34 Group 1.1 (WCB/A105/A216 WCB). Reduce for elevated temperature per ASME B16.34 Table 2. PN equivalence is indicative only — EN 1092 PN ratings use different test and design criteria.

Pressure Class Details & Typical Applications

ASME Class 150

PN 20JIS 10K

285 psi

@ 38°C (100°F)

19.6 bar

@ 38°C (100°F)

Typical use: Water, utilities, low-pressure HVAC, cooling water

Valve types: Ball valves, gate valves, globe valves — general service

ASME Class 300

PN 50JIS 20K

740 psi

@ 38°C (100°F)

51.1 bar

@ 38°C (100°F)

Typical use: Steam, medium-pressure process, chemical plants

Valve types: Gate valves, globe valves, ball valves — process service

ASME Class 600

PN 110JIS 30K / 40K

1480 psi

@ 38°C (100°F)

102.1 bar

@ 38°C (100°F)

Typical use: High-pressure steam, oil & gas pipelines, refinery service

Valve types: Forged gate/globe/check valves, trunnion ball valves

ASME Class 900

PN 150JIS 63K

2220 psi

@ 38°C (100°F)

153.2 bar

@ 38°C (100°F)

Typical use: High-pressure gas, subsea, sour service, API 6D pipelines

Valve types: Trunnion mounted ball valves, forged gate/globe, API 6D

ASME Class 1500

PN 260JIS 100K

3705 psi

@ 38°C (100°F)

255.3 bar

@ 38°C (100°F)

Typical use: High-pressure gas injection, offshore, boiler mainsteam

Valve types: Forged high-pressure valves, API 6A/6D, nuclear grade

ASME Class 2500

PN 420JIS 200K

6170 psi

@ 38°C (100°F)

425.5 bar

@ 38°C (100°F)

Typical use: Ultra-high pressure — HP gas injection, wellhead, critical power

Valve types: Compact forged valves, pressure seal bonnets, API 6A

ASME vs PN — Key Differences

ASME B16.34 classes (150, 300, 600, 900, 1500, 2500) define pressure-temperature ratings using material groups. The same class can have very different maximum pressures depending on material (WCB vs. stainless vs. alloy steel).

PN ratings (DIN/EN) are derived from a nominal pressure at 20°C. PN 20 is not exactly equivalent to ASME Class 150 — they use different calculation bases, safety factors, and test pressures.

The conversions shown are industry approximations commonly used for preliminary piping class selection only. Never mix flanges of different standards without verified compatibility.

Which Class Do I Need?

Up to 19.6 bar / 285 psi

Water, HVAC, utilities

ASME Class 150 (PN 20)

20–51 bar / 285–740 psi

Steam, process, chemical

ASME Class 300 (PN 50)

51–102 bar / 740–1480 psi

Refinery, HP steam

ASME Class 600 (PN 110)

102–153 bar / 1480–2220 psi

HP gas, sour service

ASME Class 900 (PN 150)

153–255 bar / 2220–3705 psi

Gas injection, boiler

ASME Class 1500 (PN 260)

255–426 bar / 3705–6170 psi

Wellhead, critical HP

ASME Class 2500 (PN 420)

Common Questions

Is ASME Class 150 the same as PN 20?
Approximately, but not exactly. ASME Class 150 WCB has a working pressure of 285 psi (19.6 bar) at 100°F. PN 20 is 20 bar at 20°C. They are often treated as equivalent for piping class planning, but their test pressures, safety factors, and dimensional standards differ. Never mix ASME and EN flanges without engineering verification.
What is ASME Class 300 equivalent in PN?
ASME Class 300 is approximately equivalent to PN 50. Working pressure for WCB at 100°F is ~740 psi / 51 bar. However, if you are buying European valves with EN flanges, request PN 50 rated to EN 1092 — not just 'Class 300 equivalent.'
Does pressure class rating change with temperature?
Yes — significantly. ASME B16.34 working pressures decrease as temperature rises. For example, a Class 600 WCB valve rated at 1480 psi at 100°F drops to approximately 1270 psi at 200°C (392°F) and lower at higher temperatures. Always consult the full P-T rating table for your material group.
What is the difference between Class 900 and Class 1500?
Class 900 is rated ~2220 psi at ambient, while Class 1500 is ~3705 psi — nearly double. The wall thickness, end connection dimensions, and cost increase significantly. Class 900 covers most refinery and HP gas service; Class 1500 is used for high-pressure gas injection, boiler main steam, and offshore applications.

Need Valves in a Specific Pressure Class?

We supply Class 150 to 2500 valves in WCB, SS316, Duplex, Hastelloy, and more — with full ASME B16.34 certification.

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