Name: Sockolet
Brand: Cunimet Alloy International

Product Overview

Sockolet

The Sockolet is an integrally forged, self-reinforcing branch connection fitting with a socket weld end outlet. Like the Weldolet, its contoured base is welded directly to the run pipe over a cut hole, providing a fully reinforced branch connection without the need for a separate reinforcing pad. The branch pipe end is then inserted into the socket weld bore at the top of the Sockolet and secured with a single fillet weld, making the complete joint entirely welded and suitable for high-pressure, high-temperature service.

The Sockolet is preferred over the Weldolet when smaller-bore branch connections are required in socket weld piping systems, particularly where the branch pipe is too small for a reliable full-penetration butt weld. The socket weld end avoids the need for a precision bevel weld preparation and instead uses the simpler socket weld procedure with a standard fillet weld bead.

Cunimet Alloy International manufactures Sockolets in all standard run-to-branch size combinations per MSS SP-97 in Class 3000# and 6000#. The socket bore is precision-machined to ASME B16.11 tolerances. The contoured base is machined to match the run pipe OD for each run size, ensuring a full-contact saddle fit before welding.

MSS SP-97 ASME B16.11 ASTM A182 Run: 1/2"–24" NPS Branch: 1/8"–4" NPS 3000# • 6000#

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MSS Standard SP-97

SW End Connection Type Socket Weld Fillet

1/2–24" Run Pipe Range NPS

3000# Pressure Class Also 6000#

3 Material Grades SS / Duplex / S.Duplex

Technical Dimensions

Sockolet — MSS SP-97 Branch Dimensions

“H” = Overall height from the run pipe contact face to the top face of the socket opening. Socket bore and socket depth are per ASME B16.11 for the respective branch NPS and pressure class. All dimensions in millimetres.

Branch NPS	Branch Pipe O.D. (mm)	Height “H” (mm)		Socket Bore (mm)	Socket Depth (mm)	End Type
Branch NPS	Branch Pipe O.D. (mm)	Class 3000#	Class 6000#	Socket Bore (mm)	Socket Depth (mm)	End Type
1/8"	10.3	32	38	10.5	9.5	Socket Weld
1/4"	13.7	35	41	14.0	11.1	Socket Weld
3/8"	17.1	38	44	17.3	12.7	Socket Weld
1/2"	21.3	44	51	21.6	15.9	Socket Weld
3/4"	26.7	51	57	26.9	19.1	Socket Weld
1"	33.4	57	67	33.6	22.2	Socket Weld
1-1/4"	42.2	67	79	42.4	25.4	Socket Weld
1-1/2"	48.3	76	89	48.5	28.6	Socket Weld
2"	60.3	89	102	60.5	31.8	Socket Weld
2-1/2"	73.0	108	121	73.2	38.1	Socket Weld
3"	88.9	121	140	89.1	44.5	Socket Weld
4"	114.3	146	165	114.5	50.8	Socket Weld

Heights are nominal per MSS SP-97. Base contour radius is machined to match the specific run pipe OD. All standard run-to-branch combinations are available. All dimensions in millimetres.

Product Comparison

Sockolet vs Weldolet — When to Use Which

Use a Sockolet When

The branch pipe is small bore (1/8" to 4" NPS) and the piping system uses socket weld connections throughout
A socket weld joint is preferred over a butt weld for the branch connection to simplify the welding procedure
Project specification calls for ASME B16.11 socket weld connections on all small-bore branch piping

Use a Weldolet When

The branch pipe is larger bore (1/2" to 8" NPS) and a full-penetration butt weld joint is required by the piping code
The branch connection is in high-energy service (steam, high-pressure process) where socket weld fatigue life may be a concern
Radiographic or ultrasonic examination of the branch weld joint is required and only a butt weld permits volumetric NDE

Available Materials

Material Grades for Sockolets

Grade 01

Stainless Steel 304 / 316

Austenitic stainless steel Sockolets for chemical, food and pharmaceutical piping branch connections. SS 316 provides superior resistance to chloride pitting, making it the standard specification for marine, offshore and coastal socket weld branch outlets.

ASTM A182 F304 ASTM A182 F316 MSS SP-97

Grade 02

Duplex Steel

High-strength duplex Sockolets for offshore topside piping, chemical plant process headers and desalination systems. The high yield strength allows a more compact fitting compared to austenitic grades at the same pressure rating.

ASTM A182 F51 UNS S31803 UNS S32205

Grade 03

Super Duplex Steel

Premium super duplex Sockolets with PREN greater than 40 for seawater injection headers, subsea manifold branch points, desalination plant process piping and aggressive offshore environments where maximum corrosion resistance is required.

ASTM A182 F53 UNS S32750 UNS S32760

Quality & Compliance

Standards, Testing & Documentation

Applicable Standards

Standard	Description
MSS SP-97	Integrally Reinforced Forged Branch Outlet Fittings — primary standard
ASME B16.11	Socket weld bore and depth dimensions for the SW end
ASTM A182	Material specification for forged alloy and stainless steel fittings
ASME B31.3	Process Piping — branch connection and socket weld requirements
MSS SP-25	Standard marking for fittings and flanges
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 and Charpy impact where specified
Hardness Testing	Brinell or Vickers per ASTM A182 requirements
PMI	100% XRF Positive Material Identification on request
Dimensional Inspection	100% per MSS SP-97 — height, OD, socket bore, socket depth and base contour
Visual & NDE	Visual per MSS SP-55; PT/MT on request per project spec

Applications

Where Sockolets Are Used

01

Small-Bore Branch Piping

Creating branch connections for small-bore instrument tapping lines, drain valves, vent points and sample connections on large-diameter process headers where socket weld branch outlets are specified.

02

Chemical Injection Points

Installing chemical injection quill connections on process pipelines and headers in offshore facilities and onshore plants where a socket weld branch outlet provides a permanent, corrosion-resistant injection point.

03

Offshore Topsides Piping

Duplex and Super Duplex Steel Sockolets on seawater service headers, firewater mains and process piping on offshore platforms where both corrosion resistance and compact, permanent branch connections are required.

04

Steam & Process Headers

Creating drain and vent branch connections on steam distribution headers, condensate return lines and process piping circuits in power stations and refineries where socket weld branch outlets are code-compliant.

Branch Outlets Range

Sockolet — Socket Weld Branch Outlet