This mismatch often appears when a valve package and a piping package come from different regional standards. The pressure labels may look close, and some individual sizes can appear similar. That does not authorize interchangeability across all sizes or materials.

PN16 and Class 150 Answer Different Questions

PN16 is used in a PN-designated system such as EN 1092-1. Sınıf 150 belongs to an ASME pressure-class system such as ASME B16.5. Neither label is a simple constant pressure limit for every material and temperature. The applicable standard supplies pressure-temperature ratings and dimensional tables.

A valve body marked PN16 therefore needs a companion flange that matches the valve drilling and facing specified by its manufacturer and project documents. A Class 150 valve needs the corresponding ASME interface unless the valve drawing explicitly defines another drilling pattern.

The Interface Checks That Decide Fit

1. Valve standard and face-to-face data: obtain the manufacturer drawing and exact end-connection designation.
2. Nominal size system: confirm DN and NPS rather than converting from the number alone.
3. Sondaj: compare flange outside diameter, cıvata dairesi, hole count, hole diameter and bolt size.
4. bakan: compare EN Type A/B1/B2 or the specified ASME face, including dimensions and finish.
5. Gasket: approve a gasket that matches the two controlled sealing surfaces.
6. Rating: check both components at the actual design temperature and material group.
7. Loads and assembly: confirm bolting, tightening method, piping loads and any valve restrictions.

Why a Pressure Comparison Cannot Prove Compatibility

Pressure capability depends on material and temperature. Dimensional fit depends on the standard table. These are separate checks. Two components can have adequate pressure ratings yet fail to bolt together. Conversely, a field assembly that accepts bolts may still lack an approved gasket contact area or pressure-temperature basis.

Do not solve a mismatch by slotting holes, substituting undersized bolts or forcing alignment. If the project must connect unlike standards, use an engineered adapter, transition spool or dual-drilled component only when the design authority approves the details and ratings.

RFQ Information for a Valve Companion Flange

For an ASME companion-flange route, review the ASTM A182 F316L kaynak boyunlu flanş veya ASTM A182 F316L slip-on raised face flange. Final selection must follow the valve drawing, piping specification and approved interface. Product links do not confirm stock or automatic compatibility.

Sıkça Sorulan Sorular

Is PN16 equivalent to Class 150?

No universal equivalence should be used for purchasing or installation. Compare ratings at temperature and the complete dimensional tables.

Why do the bolt holes sometimes fail to align?

EN and ASME standards can use different bolt circles, hole counts, hole diameters and outside dimensions for the nominal size.

Can a dual-drilled flange solve the problem?

Only when an approved design defines the drilling, remaining ligament, rating, karşı karşıya, gasket and marking. Treat it as a project-specific engineered item.

What is the safest procurement step?

Send the valve end-connection drawing with the flange RFQ. A standard name alone may omit the exact drilling and facing supplied by the valve manufacturer.

References and Image Source Index

1. BSI Knowledge: BS EN 1092-1:2018 overview.
2. ASME: B16.5 official scope page.
3. Company internal presentation “ASME B16.5 Flange Important Matters”: company product photographs and direct technical excerpts identified as EN 1092-1:2018 Ve ASME B16.5-2025. The licensed standards and approved valve drawing govern.