Carbon Steel Buttweld Fittings Manufacturer and Supplier in India
Kalpataru Piping manufactures and supplies carbon steel buttweld fittings for process and pipeline applications. The range includes seamless and welded elbows, tees, reducers, caps, stub ends and crosses. ASTM A234 WPB is offered for moderate- and elevated-temperature service, with ASTM A420 WPL6 for low-temperature requirements and ASTM A860 WPHY grades for high-yield pipeline applications.
Sizes range from 1/4″ NB to 48″ NB, with wall thicknesses from SCH 5S to XXS subject to fitting type, grade and size. Dimensional requirements follow ASME B16.9 or the applicable fitting standard. For accurate pricing, send the fitting type, size, schedule, material grade, quantity and inspection requirements.
Table of Contents
- What Are Carbon Steel Buttweld Fittings?
- Buttweld vs Socket Weld vs Forged Fittings
- Carbon Steel Buttweld Fittings Specifications
- Grades & Applicable Standards
- ASTM A234 WPB Chemical Composition & Mechanical Properties
- Dimension & Weight Reference
- Applications of Carbon Steel Buttweld Fittings
- Manufacturing Process & Quality Assurance
- Certifications & Documentation
- FAQ’s About Carbon Steel Buttweld Fittings
What Are Carbon Steel Buttweld Fittings?
A buttweld fitting is welded directly to the pipe end to create a continuous flow path with minimal internal obstruction. This connection is widely used in process piping where pressure, temperature, flow continuity and joint integrity are important. Selection between buttweld, socket-weld and forged fittings depends on pipe size, service conditions, applicable piping code and project specification rather than a fixed 2-inch cut-off.
- Buttweld vs Socket Weld vs Forged Fittings
- Specifications
- Chemical Composition & Mechanical Properties
- Grades & Applicable Standards
- Dimension & Weight Chart
Buttweld vs Socket Weld vs Forged Fittings
|
Parameter |
Buttweld Fittings |
Socket Weld Fittings |
Forged Fittings |
|
Joint type |
Welded end-to-end; continuous bore |
Pipe inserted into a recessed socket, then fillet welded |
Threaded or socket-welded connection, depending on fitting type |
|
Typical size range |
Available across small- to large-bore sizes; often selected for medium- and large-bore process piping |
|
|
|
Internal flow |
Full-bore path with minimal internal obstruction |
Internal recess/crevice is present at the socket |
Depends on connection type |
|
Best suited for |
|
|
Compact, high-pressure connections |
Carbon Steel Buttweld Fittings Specifications
|
Parameter |
Recommended final detail |
|
Material Standard |
ASTM A234 / ASME SA234 Grade WPB. DIN and other legacy grades can be listed separately only where actually supplied. ASTM A105 should not be presented as a buttweld-fitting material grade. |
|
Low-Temperature Grades |
ASTM A420 WPL3, WPL6, WPL9, where offered |
|
High-Yield Grades |
ASTM A860 WPHY 42, WPHY 46, WPHY 52, WPHY 60, WPHY 65, WPHY 70 |
|
Dimension Standards |
ASME B16.9; ASME B16.28 for short-radius elbows/returns; ASME B16.25 for butt-welding end preparation; MSS SP-75 where applicable to high-strength WPHY fittings |
|
Size Range |
1/4″ NB to 48″ NB |
|
Wall Thickness |
SCH 5S, 10S, 20S, STD, 40S, 60, XS, 80, 100, 120, 140, 160, XXS |
|
Type |
Seamless, welded and fabricated |
|
End Finish |
Beveled ends to ASME B16.25. Other end preparations should be listed separately where specifically applicable. |
|
Testing |
Chemical analysis, mechanical testing, PMI, dimensional inspection and NDE/testing as required by the applicable specification or purchase order |
|
Certification |
EN 10204 3.1 / 3.2 Mill Test Certificate, IBR documentation and third-party inspection on request |
ASTM A234 WPB Chemical Composition & Mechanical Properties
Chemical Composition — ASTM A234 WPB (Max %)
Element |
Composition Requirement |
Carbon (C) |
0.30–0.35 max, as applicable |
Manganese (Mn) |
0.60–1.06, as applicable |
Phosphorus (P) |
0.035–0.050 max, as applicable |
Sulfur (S) |
0.040–0.058 max, as applicable |
Silicon (Si) |
0.10–0.35 or 0.10 min, subject to the applicable ASTM requirements and footnotes |
Chromium (Cr) |
0.30–0.40 max, as applicable |
Molybdenum (Mo) |
0.12–0.15 max, as applicable |
Nickel (Ni) |
0.40 max, where applicable |
Copper (Cu) |
0.40 max, where applicable |
Vanadium (V) |
0.08 max |
Mechanical Properties — ASTM A234 WPB
|
Property |
Recommended Final Detail |
|
Ultimate Tensile Strength, Min. |
60 ksi (415 MPa) |
|
0.2% Yield Strength, Min. |
35 ksi (240 MPa) |
|
Elongation, Min. |
Use the specimen-specific requirement of the applicable ASTM specification; do not publish one generic percentage |
|
Reduction of Area |
Remove unless specifically required and supported by the applicable ASTM specification or MTC |
|
Hardness, Max. |
Use the hardness limit specified by the applicable ASTM grade/specification; do not generalize 187 HBW or 197 HBW without confirmation |
Grades & Applicable Standards
Carbon Steel Grades
| Grade | Description |
| WPB | Standard service, most commonly used |
| WPBW | WPB fitting of welded construction; use the exact marking/heat-treatment terminology from the applicable ASTM edition and MTC. |
| WPHY 42 / 46 / 52 | High yield strength grades — pipeline service |
| WPHY 60 / 65 / 70 | Higher yield strength grades — high-pressure pipeline service |
Low-Temperature Grades
| Grade | Standard | Service Temperature |
| WPL3 | ASTM A420 | -150°F (-100°C) ASTM impact-test temperature; do not present as a blanket service-temperature guarantee |
| WPL6 | ASTM A420 |
50°F ASTM impact-test temperature: -50°F (-45°C) |
| WPL9 | ASTM A420 | -100°F (-75°C) ASTM impact-test temperature; do not present as a blanket service-temperature guarantee |
Applicable Standards
| Standard | Description |
| ASTM A234 | Material specification |
| ASME B16.9 | Factory-made wrought buttwelding fittings |
| ASME B16.28 | Short radius elbows and returns |
| MSS-SP-43 | Remove from the core WPB standards list unless a specific low-pressure corrosion-resistant fitting scope genuinely applies. |
| ASME B16.25 | Bevel end details |
| IBR | Indian Boiler Regulation Present under certification/regulatory compliance, not as a dimensional/material standard. |
Dimension & Weight Reference
A complete dimension and weight chart across all NPS 1/4″ to 48″ and every schedule is available on request. Sample values below for 90° long radius elbows:
|
NPS |
Outside Diameter (mm) |
90° LR Elbow — STD Weight (kg) |
90° LR Elbow — XH Weight (kg) |
|
1/2″ |
21.3 |
0.10 |
0.12 |
|
1″ |
33.4 |
0.20 |
0.26 |
|
2″ |
60.3 |
0.78 |
1.09 |
|
4″ |
114.3 |
4.00 |
5.71 |
|
6″ |
168.3 |
10.25 |
16.66 |
|
8″ |
219.1 |
21.10 |
32.16 |
|
12″ |
323.9 |
56.20 |
92.70 |
Types of Carbon Steel Buttweld Fittings
_Carbon Steel Bend
_Carbon Steel Concentric Reducer
_Carbon Steel Equal Tee
_Carbon Steel Long Stub End
_Carbon Steel Short Stub End
Carbon Steel 45 Degree Elbow
Carbon Steel Eccentric Reducer
Carbon Steel End Cap
Carbon Steel Equal Cross
Carbon Steel Lateral Tee
Carbon Steel Pipe Fittings
Applications of Carbon Steel Buttweld Fittings
Where these fittings actually end up on a project:
- Off-shore oil drilling and upstream production
- Power generation — steam and boiler piping
- Petrochemicals and gas processing
- Specialty chemicals and pharmaceutical utility piping
- Sea water systems, heat exchangers, and condensers
- Pulp and paper processing lines
On most jobs, fittings ship alongside carbon steel flanges and the matching A106/A53/API 5L Grade B pipe from the same order — saves a coordination headache later in the project.
Certifications & Documentation
- ISO 9001:2015 Quality Management Certification
- IBR (Indian Boiler Regulation) approval available
- Mill Test Certificate per EN 10204 3.1 / 3.2
- Third-party inspection through SGS, TUV, or Bureau Veritas, on request
- Positive Material Identification (PMI) and radiographic test reports on request
You can see the rest of what we stock in our full catalog.
Frequently Asked Questions
What are Carbon Steel Buttweld Fittings?
Carbon Steel Buttweld Fittings are piping components used to connect, change direction, reduce pipe size, or terminate pipelines. They are welded directly to pipes to provide strong, leak-proof, and permanent connections.
What are Carbon Steel Buttweld Fittings used for?
Carbon Steel Buttweld Fittings are used in oil and gas, petrochemical, power generation, chemical processing, water treatment, and industrial piping systems that operate under high pressure and temperature.
What is the difference between Carbon Steel Buttweld Fittings and Forged Fittings?
Carbon Steel Buttweld Fittings are welded to pipes and are commonly used in larger pipe sizes, while Forged Fittings are threaded or socket welded and are typically used for smaller pipe sizes and high-pressure applications.
What schedules are available for Carbon Steel Buttweld Fittings?
Carbon Steel Buttweld Fittings are commonly available in Schedule 10, Schedule 20, Schedule 40, Schedule 80, Schedule 160, and XXS, depending on the pipe size and application requirements.
Are Carbon Steel Buttweld Fittings suitable for high-temperature applications?
Yes, Carbon Steel Buttweld Fittings are suitable for high-temperature and high-pressure applications when manufactured in appropriate grades such as ASTM A234 WPB and used within their specified operating limits.
Can Carbon Steel Buttweld Fittings be welded?
Yes, Carbon Steel Buttweld Fittings are specifically designed for butt welding, creating strong, durable, and leak-free joints in industrial piping systems.
