HomeBlog › Valve End Connections: Flanged vs Threaded vs Welded

Valve End Connections: Flanged vs Threaded vs Welded

Valve end connection guide: threaded, flanged, butt weld and socket weld 鈥?size, pressure, pros, cons and flange standards explained.

Why End Connection Matters

The end connection determines how a valve joins your pipeline 鈥?affecting installation speed, maintenance, leak risk, and cost. Whether you choose a ball, gate, butterfly, control, or check valve, the same three families of connections apply.

Comparison Table

ConnectionSize / PressureProsCons
Threaded (BSP/NPT)DN15鈥揇N50 / lowFast, cheap, no special toolsLeak risk at high pressure
Flanged (ANSI/DIN/JIS)DN25鈥揇N1200 / allRemovable, standard, strongBulky, gasket care needed
Butt Weld (BW)All / highZero external leak, permanentCannot remove without cutting
Socket Weld (SW)DN15鈥揇N50 / highEasy alignment, strongBorn crevice, harder to inspect

Flange Standards

Flange drilling differs by region: ANSI/ASME B16.5 (North America), EN 1092-1 / DIN (Europe, common in the Middle East), and JIS B2220 (Japan, used in parts of Asia). Confirm your pipeline standard before ordering 鈥?Reguvale stocks all three and can drill to match.

Recommendation by Application

For skid and instrument lines use threaded. For plant mains and anything you may need to service, use flanged. For subsea, high-pressure gas, or nuclear-grade permanent lines, use butt-welded. Not sure which your project needs? Our team will match it to your spec sheet.

Need a specific connection? Tell us your flange standard, size, and pressure class. Reguvale delivers valves drilled and faced to your exact requirement, with third-party inspection available.

Frequently Asked Questions

Threaded, flanged or welded 鈥?which is best?

Threaded (BSP/NPT) suits small sizes up to DN50 and low pressure. Flanged is the industrial standard above DN25 and allows easy removal. Butt-welded gives the highest integrity with zero external leakage risk for high-pressure gas and permanent installations.

Can I mix connection standards (ANSI flange on DIN pipe)?

Yes, but you need the correct flange drilling. ANSI (ASME B16.5), DIN (EN 1092-1), and JIS flanges have different bolt-circle diameters and pressures. Reguvale can supply any standard; just specify your pipe flange standard when ordering.

When is socket weld used instead of butt weld?

Socket weld is common for small high-pressure lines (DN15鈥揇N50) where alignment is easier and full penetration is less critical. Butt weld is preferred for larger sizes and where smooth bore matters for flow and cleaning.

Do all Reguvale valves support actuation regardless of connection?

Yes. Pneumatic and electric actuators mount via the ISO 5211 pad on the valve stem, independent of the end connection. Threaded, flanged, and welded versions can all be automated.

View Gate Valves → Request a Quote