The Stainless Steel Pipe Cap is a butt weld fitting used to permanently close the end of a stainless steel pipe in corrosive or high purity service. The cap has a domed (elliptical) shape that distributes internal pressure stress evenly — much safer than a flat plate welded to the pipe end. The fitting is manufactured from ASTM A403 stainless steel, with WP304/304L or WP316/316L material grades. Low carbon “L” grades are recommended for welded systems to prevent carbide precipitation at the weld heat-affected zone. The open end is beveled per ASME B16.25 to match the pipe bevel. For pharmaceutical and food applications, an electropolished internal surface is available. A small vent hole (1/8″ or 1/4″ NPT) can be added to allow pressure testing of dead-leg lines.
Why Choose Us / Advantage
316L Standard for Pharma: We recommend 316L for weldable, corrosion resistant closures.
Vent Hole Optional: Prevents trapped air during hydrostatic testing.
Full Traceability: Heat number stamped on each cap.
Electropolish Available: Ra 0.4μm finish for clean-in-place (CIP) systems.
Quick Stock: 1/2″ – 12″ caps available for immediate shipment.
Technical Data
★ Specification SS304/L SS316/L
★ Material ASTM A403 WP304 / WP304L ASTM A403 WP316 / WP316L
★ Shape Elliptical (standard) Elliptical
★ Connection Butt weld (beveled ends) Butt weld
★ Schedule Sch10S – Sch80S Sch10S – Sch80S
★ Size Range 1/2″ – 24″ 1/2″ – 24″
★ Standard ASME B16.9 ASME B16.9
★ Vent Hole Optional (NPT threaded) Optional
★ Finish Pickled & passivated Pickled & passivated
Applications
● Dead-leg termination in pharmaceutical water systems
● End closure for chemical transfer lines
● Future expansion connection points (capped nozzle)
● Sanitary processing lines during cleaning
● Marine seawater line terminations
