Socket Weld Flanges

Socket Weld Flanges are pipe flanges with an internal shoulder designed to position a pipe for fillet welding in high-pressure piping systems.

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Product Introduction

Product Overview

Socket Weld Flanges are pipe flanges with an internal shoulder designed to position a pipe for fillet welding in high-pressure piping systems.

Machined counterbore aligns with the pipe bore to reduce internal mismatch and flow disturbance at the joint.

Dual-radius hub transitions are designed to reduce stress concentration near the weld heat-affected zone (HAZ).

Reduces the need for pipe-end beveling before welding, which may shorten pre-assembly preparation time.

Helps reduce weld spatter entering the pipe bore during fillet welding, supporting line cleanliness.

Category	Standard / Certification / Test	Verification & Compliance Scope
Material Traceability	EN 10204 Type 3.1	Chemical & mechanical traceability by heat number
Material Traceability	NACE MR0175 / ISO 15156	Sour service resistance (H₂S hardness & sulfur control)
Quality Management	ISO 9001:2015	Full QA system from forging to final inspection
Quality Management	PED 2014/68/EU (Section 4.3)	EU pressure equipment manufacturer approval
Nondestructive Testing	ASTM E165 (LPT)	Surface defect detection on machined sealing areas
Nondestructive Testing	ASTM E709 (MT)	Surface/near-surface defect detection in stress zones
Material Verification	PMI (Positive Material Identification)	Alloy grade confirmation via spectrometry

Socket diameters are controlled within +/-0.25 mm tolerances to maintain dimensional fit with the pipe.

100% magnetic particle testing on weld hubs is performed to identify surface micro-fissures before shipment.

Flange face finish is maintained at Ra 3.2–6.3 μm in accordance with ASME B16.5 gasket surface requirements.

100% Positive Material Identification (PMI) verifies exact chemical compositions to prevent alloy grade mix-ups.

Hydrostatic testing verifies pressure-containing capability according to ASME B16.5 requirements.

Application Field	How It Is Used
Chemical Processing	Small-bore piping for toxic or corrosive fluids
Petroleum Refining	High-pressure hydrocarbon distribution lines
Power Generation	Auxiliary steam and condensate drainage systems
Water Treatment	High-pressure RO (reverse osmosis) skid piping
Marine Engineering	Compact fuel and lubrication piping systems

Annual forging capacity is over 5,000 tons, configured for standard and custom small-bore components.

Twenty multi-axis CNC lathes are used for sizing of internal sockets and bores.

Standard size orders typically ship within 15 to 20 days after drawing approval.

Raw material feedstock buffer maintains 300 tons of carbon and stainless steel bars.

Custom material forging runs require an estimated lead time of 4 to 6 weeks.

Q: Can Socket Weld Flanges be provided with galvanized coatings for corrosive outdoor utilities?

A: Yes. Hot-dip galvanizing can be applied in accordance with ASTM A153 for atmospheric corrosion protection.

Q: Do you stock specific raw materials for low-temperature service environments?

A: Forged ASTM A350 LF2 carbon steel blocks are regularly stocked to accommodate low-temperature orders.

Q: Is it possible to request custom stamped tracking numbers on the outer rim?

A: CNC dot-peen marking on the flange rim is standard for direct heat-number traceability.

Q: What type of rust preventative oil is applied to the machined surfaces before packaging?

A: A light, solvent-removable rust inhibitor is applied to protect bare metal during sea freight.

Q: Are end plastic caps included to protect the internal socket during transit?

A: Molded plastic caps are provided to protect machined sockets and raised faces during transit.

Q: Do you offer third-party inspection alignment with agencies like Lloyd's or SGS?

A: We accept third-party inspectors (SGS, BV, Lloyd's) and provide full access to testing facilities.

Q: What is the standard seaworthy packaging used for international LCL shipments?

A: Parts are packed in ISPM-15 certified wooden cases lined with vapor-corrosion-inhibitor plastic film.