What flange types do you manufacture?

We supply weld neck (WN), slip-on (SO), blind, socket weld (SW), lap joint (LJ) and threaded flanges to ASME B16.5 (1/2 inch to 24 inch) and ASME B16.47 Series A/B for larger diameters. Facings include raised face (RF), flat face (FF) and ring-type joint (RTJ), in pressure classes 150, 300, 600, 900, 1500 and 2500.

Which flange should I use — weld neck or slip-on?

A weld neck flange has a tapered hub butt-welded to the pipe and is preferred for high-pressure, high-temperature and cyclic service because it transfers stress smoothly and allows full radiography of the weld. A slip-on flange slides over the pipe and is fillet welded inside and out — cheaper and easier to align, suited to lower-pressure service. Both are supplied to ASME B16.5 across our full material range.

IBR Approved · Flanges

Pipe Flange Manufacturer

Weld neck, slip-on, blind, socket weld, lap joint and threaded flanges to ASME B16.5 / B16.47 — in carbon, alloy, stainless and duplex steel. Class 150 to 2500, RF / FF / RTJ. IBR approved, EN 10204 3.1 / 3.2 traceable.

WN / SO / Blind Class 150 – 2500 ASME B16.5 / B16.47 RF / FF / RTJ

Overview

Flanges provide bolted, gasketed connections that allow piping, valves and equipment to be assembled and dismantled without cutting. We manufacture the full range of forged flanges to ASME B16.5 (through 24") and ASME B16.47 Series A / B for larger diameters, in pressure classes 150 through 2500 and RF, FF and RTJ facings.

Flanges are forged to the applicable material specification (A105 carbon steel, A182 alloy and stainless, A182 F51/F53 duplex), supplied with EN 10204 3.1 or 3.2 test certificates and, for boiler and steam service, IBR Form III-C certification.

Flange Types & Standards

Type	Standard	Typical Use
Weld Neck (WN)	ASME B16.5 / B16.47	High pressure, cyclic & high-temp service
Slip-On (SO)	ASME B16.5	Lower-pressure, easy-alignment service
Blind	ASME B16.5 / B16.47	Sealing flanged openings & vessels
Socket Weld (SW)	ASME B16.5	Small-bore high-pressure lines
Lap Joint (LJ)	ASME B16.5	With stub ends, frequent dismantling
Threaded	ASME B16.5	Non-welded, utility & instrument lines

Available Material Grades

Flanges are forged from the equivalent grade to the buttweld fittings. Click a grade for full specification, chemistry and mechanical data:

A105 — Carbon steel A350 LF2 — Low-temp CS F11 — 1.25Cr-0.5Mo F22 — 2.25Cr-1Mo F91 — 9Cr-1Mo-V F92 — 9Cr USC F5 — 5Cr-0.5Mo F9 — 9Cr-1Mo F304 / 304L — Stainless F316 / 316L — Stainless F321 — Stabilised SS F51 Duplex 2205 — PREN ~35 F53 Super Duplex — PREN ~42

Technical Specifications

Parameter	Range
Size range	1/2" to 24" (B16.5), 26" to 48"+ (B16.47)
Pressure classes	150, 300, 600, 900, 1500, 2500
Facings	Raised Face (RF), Flat Face (FF), Ring-Type Joint (RTJ)
Dimensional standard	ASME B16.5 / B16.47 Series A & B
Certification	EN 10204 3.1 / 3.2 · IBR Form III-C
Testing	PMI, dimensional, hardness, DP / UT as specified

Related Fitting Types

Buttweld Elbows → Buttweld Tees → Stub Ends → All Products →

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