Fitting carbon steel and low-alloy steel pipe fittings are the most fundamental and widely used connecting components in industrial piping systems, applied in oil & gas, petrochemicals, power generation, shipbuilding, water treatment, construction, and mechanical engineering. The product range includes elbows, tees, reducers, caps, and unions, manufactured from high-quality carbon or low-alloy structural steels through hot extrusion, cold forming, forging, and heat treatment processes. These fittings offer excellent mechanical strength, weldability, and cost-effectiveness, serving as critical elements for reliable operation in medium- and high-pressure piping systems.
Key Features
Standards:
International Standards:
ASME B16.9 (Factory-Made Wrought Steel Buttwelding Fittings)
ASME B16.11 (Forged Steel Socket-Welding and Threaded Fittings)
MSS SP-75 (High-Strength Forged Fittings)
ASTM A234 WPB (Carbon and Alloy Steel Forged Fittings)
ASTM A420 WPL6 (Low-Temperature Forged Fittings)
European Standards:
EN 10253 (Butt-Welding Fittings)
EN 10241 (Threaded Fittings)
Chinese Standards:
GB/T 12459 (Seamless Steel Butt-Welding Fittings)
GB/T 13401 (Welded Steel Butt-Welding Fittings)
GB/T 14383 (Forged Steel Fittings)
HG/T 21631 (Socket-Welded Steel Fittings)
SH/T 3408 (Petrochemical Carbon Steel Buttwelding Fittings)
Materials:
Carbon Steel Fittings:
ASTM A234 WPB (Most common, for general service)
ASTM A105 (For non-pressure or small bore fittings)
Q235, Q345B (Chinese standards, for general or low-pressure systems)
Low-Alloy Steel Fittings:
ASTM A234 WPC (High-strength carbon steel)
ASTM A234 WP11 / WP22 (Cr-Mo steel for high temperature)
ASTM A420 WPL6 (Low-temperature carbon steel, impact tested at -46°C)
16Mn, 15CrMo, 12Cr1MoV (Domestic grades for high-temp or low-temp service)
All materials meet chemical, mechanical, and heat treatment requirements per applicable standards, with heat treatment reports provided.
Dimensions:
Nominal Diameter (DN): DN15 (1/2") to DN1200 (48")
Wall Thickness: SCH20, SCH40, SCH80, XS, XXS; STD, Schedule 160
Types & Angles:
Elbows: 90°, 45°, 180° (Long Radius LR, Short Radius SR)
Tees: Equal Tee, Reducing Tee
Reducers: Concentric, Eccentric
Connection Types: Butt-Weld, Socket Weld, Threaded
Applications:
Carbon Steel Fittings: Suitable for ambient temperature and medium/low-pressure environments, such as:
Building water supply and drainage
General industrial piping
Ship auxiliary lines
Water treatment equipment
Oil & gas gathering pipelines
Low-Alloy Steel Fittings: Used in high-temperature, low-temperature, or high-pressure environments, such as:
Oil refining units (high-temp lines, WP11/WP22)
LNG cryogenic pipelines (WPL6 material)
Power plant steam systems (15CrMo)
Offshore platform process lines
Long-distance transmission pipelines (X42-X70 grades)
Certifications & Approvals:
Classification Society Certifications: ABS, DNV, LR, BV, NK, CCS, NORSOK M650
Provide Type Approval Certificates and Mill Test Certificates + Third-Party Inspection Reports per batch
Owner & Engineering Company Approvals:
ISO 9001 Quality Management System
API 5L (for line pipe fittings)
PED 2014/68/EU (Pressure Equipment Directive)
AD 2000-Merkblatt (German pressure vessel code)
Approved by GE,CNPC, Sinopec, CNOOC, Shell, ExxonMobil, Total, Chevron, etc.
Common Customer Questions (Q&A Format)
Q: What is the main difference between carbon steel and low-alloy steel fittings?
A: Carbon steel fittings are cost-effective for normal conditions; low-alloy steels contain Cr, Mo, offering higher strength, temperature, or low-temperature resistance for severe service.
Q: How to select the right fitting material?
A: Choose based on temperature, pressure, medium, and environment:
Ambient conditions: A234 WPB or Q235;
Low-temp (-46°C): A420 WPL6;
High-temp (>400°C): A234 WP11/WP22 or 15CrMo.
Q: Do you support non-standard fitting designs?
A: Yes, custom designs based on customer drawings or ASME B16.9/EN 10253, with FEA analysis support.
Q: What are the heat treatment conditions?
A: Carbon steel fittings: Typically normalized or annealed;
Low-alloy steel fittings: Usually normalized & tempered for improved toughness.
Q: Are NDT services available?
A: Yes, MT, UT, PT available upon request, especially for Class 600+ or low-temperature fittings.
Q: How to protect fitting ends during shipping?
A: Butt-weld ends with plastic guards, large-diameter fittings secured in wooden crates or steel frames, overall moisture-proof and impact-resistant packaging.
Q: Do your fittings comply with PED?
A: Yes, for EU markets, we provide CE marking per PED 2014/68/EU, including material traceability, design validation, and third-party inspection.
Q: What is the lead time?
A: Standard products: 15–30 days; non-standard or large-diameter: 45–90 days, depending on material, quantity, and heat treatment.
Q: How is dimensional accuracy ensured?
A: CNC forming and machining with tolerances within ±0.5mm, supported by CMM reports.
Q: Is material traceability provided?
A: Yes, each batch includes a Material Test Certificate (MTC 3.1 or 3.2) with heat number, chemistry, mechanical properties, and heat treatment records for full lifecycle traceability.
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