The Carbon Steel Pipe Cap is a butt weld fitting used to permanently close the end of a pipe. It is commonly used at the end of dead-leg lines, future connection points, or at the termination of a pipeline. The cap has a domed or elliptical shape that provides uniform stress distribution under internal pressure — much stronger than a flat plate welded to the pipe end. The fitting is manufactured from carbon steel to ASTM A234 WPB (standard service) or ASTM A420 WPL6 (low temperature service). The open end is beveled per ASME B16.25 to match the pipe bevel for field butt welding. Caps are available in all standard pipe schedules (Sch10 through Sch160) and can be supplied with a small vent hole if required for pressure testing.
Why Choose Us / Advantage
Pressure Rated: Designed to same pressure rating as the connecting pipe.
Elliptical Shape Standard: Better stress distribution than flat caps.
Vent Hole Option: 1/8″ or 1/4″ NPT vent available for test connections.
100% Dimensional Check: Ensures proper fit-up with your pipe.
Low Temperature Option: A420 WPL6 for -50°C service.
Technical Data
★ Material Carbon Steel ASTM A234 WPB
★ Shape Elliptical (standard) / Hemispherical
★ Connection Butt weld (beveled ends)
★ Pressure Sch10 – Sch160 / STD / XS / XXS
★ Size Range 1/2″ – 48″ (DN15 – DN1200)
★ Standard ASME B16.9 / MSS SP-75
★ Vent Hole Optional (upon request)
Applications
● End of pipeline dead-legs
● Future expansion connection points (capped for later use)
● Pressure vessel nozzle closures
● Blowdown stack terminations
● Temporary pipe ends during construction
