ASME B16.9 Stub End Carbon Steel — Factory Direct Supplier | Huaxia-Steel
ASME B16.9 stub ends are short butt-weld fittings welded to pipe ends and used together with lap-joint flanges to create a flanged joint that can be rotated for bolt-hole alignment during installation. They are a staple of refinery, chemical, and offshore piping because they allow field alignment without rotating the pipe itself. Huaxia-Steel supplies Type A and Type B B16.9 stub ends in carbon steel grades from Chinese mills.
Product Overview
A stub end has one short butt-weld end (the barrel) that welds to the run pipe and a flared flange end that mates with the lap-joint flange. Two variants exist:
- Type A – thick lap, machined to MSS-SP-43 dimensions. Most common in industrial piping. Long or short pattern variants offered.
- Type B – thin lap, machined to ASME B16.5 lap-joint flange dimensions. Used when the stub end must match a standard flange thickness.
Specifications
| Item | Details |
|---|---|
| Standard | ASME B16.9 (Type A or Type B) |
| Material grades | ASTM A234 WPB, WPC, WPRA |
| Size range | NPS 1/2 to NPS 48 (DN 15 to DN 1200) |
| Wall thickness | SCH 10S, 20S, STD, SCH 40, XS, SCH 80, SCH 120 |
| Type | Type A (long or short) or Type B |
| Lap diameter | MSS-SP-43 / ASME B16.5 compatible |
| Surface | As-formed, shot-blasted, primed, or oiled |
| End preparation | Beveled per ASME B16.25 |
Available Grades
From the same production lines we also supply:
- ASTM A234 WPB – the standard carbon grade, matches A106 Gr.B and A53 Gr.B pipe
- ASTM A234 WPC – higher carbon for elevated-temperature service
- ASTM A420 WPL6 – low-temperature carbon steel for cryogenic and LNG service
- ASTM A860 WPHY 42 / 46 / 52 / 60 / 65 – high-strength low-alloy variants
- ASTM A234 WP9 / WP11 / WP22 – chrome-moly variants for power-station superheaters
Manufacturing Standards
- ASME B16.9 (factory-made wrought butt-welding fittings)
- ASME B16.5 (pipe flanges and flanged fittings – matches Type B stub ends)
- MSS-SP-43 (Type A stub ends)
- ASTM A234 (wrought carbon and alloy steel fittings)
- ASTM A960 (general requirements for ferritic alloy fittings)
- ASME B31.1 / B31.3 (power and process piping code)
Applications
- Refinery and petrochemical pipe rack flanged joints
- Field-aligned equipment connections (pumps, exchangers, vessels)
- Chemical and pharmaceutical process headers
- Marine and offshore deck piping
- Power plant condensate and feedwater systems
- Water and waste water treatment plants
Why Choose a Stub End Over a Standard Flange?
Stub ends are widely preferred where frequent bolt-up alignment is required, where pipework is pre-fabricated off-site, or where the operating environment demands regular joint disassembly:
- Field alignment – the lap-joint flange can rotate freely around the stub end; bolt holes align without rotating the pipe.
- Lower cost – the lap-joint flange is a low-pressure, non-corrosive-service part (often made of carbon steel). The stub-end carries the corrosion-resistant alloy.
- Easier dismantling – when maintenance or replacement is needed, only the lap-joint flange rotates off; the stub end stays welded in place.
Quality Assurance
Each B16.9 stub end is dimensionally inspected per ASME B16.9 (or MSS-SP-43 for Type A). Material certificates to EN 10204 3.1 trace the heat number and mechanical properties. 100% ultrasonic testing of the weld seam is available for critical service. Third-party inspection by SGS, BV, or TUV is standard for export orders.
Packing and Shipping
Small stub ends (NPS 1 to NPS 6) are typically crated in wooden boxes with foam separators. Larger stub ends are individually wrapped in VCI paper and strapped onto pallets or timber frames. Each stub end is end-capped on the barrel side and the flared side is protected by a foam liner or plywood disk to prevent transit damage. FOB, CFR, CIF, and DDP terms are available from major Chinese ports.
Why Buy ASME B16.9 Stub Ends from Huaxia-Steel?
- Mill-direct pricing for both Type A and Type B variants
- Wide size range from NPS 1/2 to NPS 48
- ASTM A234 WPB and WPC available in long and short patterns
- Compatible with all major lap-joint flanges (ASME B16.5, MSS-SP-44)
- Dimensional inspection report and EN 10204 3.1 certificate per lot
- Coordinated supply with lap-joint flanges and butt-weld elbows to consolidate shipments
Need ASME B16.9 stub ends for a process project? Send the size, schedule, type (A or B), grade, and quantity. Our team will deliver a complete offer within one working day.
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