Socket Weld Cap – Forged SS 304 316 Duplex Super Duplex

Product Overview

Forged SW Cap

The Socket Weld Cap is a forged end closure fitting used to permanently blank off the open end of a pipe. The pipe end is inserted into the precision-machined socket and secured with a single fillet weld, forming a completely enclosed, high-pressure-rated termination. The opposite end of the fitting is a solid forged dome that provides the full pressure containment.

SW caps are used wherever a pipe end must be permanently closed in a high-pressure system — during construction for pipe end protection and pressure testing, or in permanent service to blank off unused branch outlets, valve tie-ins and future connection points. The fully forged body offers higher integrity than fabricated alternatives using a plate welded over the pipe end.

ASME B16.11 MSS SP-79 1/8" to 4" NPS 3000# • 6000# One SW Socket + Closed End

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ASMEStandardB16.11

1SW SocketClosed Forged End

1/8–4"Size RangeNPS

3000#Pressure ClassAlso 6000#

3Material GradesSS / Duplex / S.Duplex

Technical Dimensions

SW Cap — ASME B16.11 Dimensions

“L” = Overall length from socket opening to closed end. All dimensions in millimetres.

NPS	Pipe O.D. (mm)	Overall Length “L” (mm)		Socket Bore (mm)	Socket Depth (mm)	O.D. at Body (mm)
NPS	Pipe O.D. (mm)	Class 3000#	Class 6000#	Socket Bore (mm)	Socket Depth (mm)	O.D. at Body (mm)
1/8"	10.3	19	22	10.5	9.5	20.6
1/4"	13.7	22	22	14.0	11.1	25.4
3/8"	17.1	22	25	17.3	12.7	31.8
1/2"	21.3	25	29	21.6	15.9	38.1
3/4"	26.7	29	35	26.9	19.1	47.6
1"	33.4	35	44	33.6	22.2	57.2
1-1/4"	42.2	41	48	42.4	25.4	69.9
1-1/2"	48.3	48	51	48.5	28.6	79.4
2"	60.3	51	57	60.5	31.8	95.3
2-1/2"	73.0	57	67	73.2	38.1	114.3
3"	88.9	67	79	89.1	44.5	136.5
4"	114.3	79	95	114.5	50.8	171.5

Dimensions are nominal per ASME B16.11 latest edition. Subject to manufacturing tolerances. All dimensions in millimetres.

Available Materials

Material Grades for SW Caps

Grade 01

Stainless Steel 304 / 316

Austenitic stainless steel end closures for chemical, water treatment, food and pharmaceutical piping systems. SS 316 recommended for chloride-bearing, marine and coastal environments.

ASTM A182 F304ASTM A182 F316ASME B16.11

Grade 02

Duplex Steel

High-strength duplex end caps for offshore, chemical plant and desalination pipe blanking where chloride stress corrosion cracking resistance and elevated yield strength are required.

ASTM A182 F51UNS S31803UNS S32205

Grade 03

Super Duplex Steel

Premium super duplex caps with PREN greater than 40 for seawater service, subsea systems and aggressive chloride environments where maximum corrosion resistance is mandatory.

ASTM A182 F53UNS S32750UNS S32760

Quality & Compliance

Standards, Testing & Documentation

Applicable Standards

Standard	Description
ASME B16.11	Forged Fittings, Socket-Welding & Threaded — dimensional standard
ASTM A182	Material specification for forged alloy and stainless steel fittings
ASME B31.3	Process piping code governing socket weld procedures
MSS SP-25	Standard marking system for forged fittings
MSS SP-55	Visual inspection acceptance criteria for forgings
EN 10204	3.1 MTC standard; 3.2 with TPI on request

Quality Tests Performed

Test	Method / Scope
Chemical Analysis	OES per ASTM A182 for each heat
Mechanical Testing	Tensile, yield, elongation, Charpy impact where specified
Hardness Testing	Brinell or Vickers per ASTM A182
PMI	100% XRF on request
Dimensional Inspection	100% per ASME B16.11 — socket bore, depth, wall and overall length
Visual Inspection	100% per MSS SP-55

Applications

Where SW Caps Are Used

01

Pipe End Blanking

Permanently closing off dead-end pipe legs, unused branch connections and future tie-in points in process piping systems where a permanent welded closure is required.

02

Pressure Testing

Temporarily blanking pipe ends during hydrostatic and pneumatic pressure testing of piping systems before final connection to equipment, removing after testing is complete.

03

Valve & Equipment Tie-Ins

Capping future valve connection stub-outs and equipment nozzles during construction phases, maintaining system pressure boundaries until the connected equipment is commissioned.

04

Offshore & Subsea

Permanent end closures on offshore topside piping and subsea flowline terminations in Duplex and Super Duplex Steel where full weld-integrity end blanking is required in seawater service.

Socket Weld Fittings Range

Socket Weld Cap