Stainless Steel 347H Pipes Manufacturer in India
Stainless Steel 347H Pipes Manufacturer in India
Sachiya Steel International is a leading Stainless Steel 347H Pipes Manufacturer in India, established in 2005 and based in Mumbai. With over 20 years of experience, we manufacture, supply, and export industrial pipes and tubes to customers in 85+ countries. Our product range includes stainless steel, duplex, super duplex, carbon steel, alloy steel, and nickel alloy pipes for different industrial and engineering needs. We focus on product quality, material traceability, and dependable supply for standard orders, bulk quantities, and project requirements.
Our quality systems are supported by ISO 9001:2015, ISO 14001:2015, ISO 45001:2018, and applicable TÜV certifications. We supply Stainless Steel 347H Pipes in seamless and welded forms, with different sizes, schedules, and finishes available to match project specifications. The grade is stabilised with niobium and designed for applications that require strength at elevated temperatures. With inspection and material documentation available as required, we support industries such as oil and gas, petrochemicals, power generation, and chemical processing.
What Are Stainless Steel 347H Pipes?
Stainless steel 347H pipes are austenitic stainless steel pipes made from UNS S34709, a niobium-stabilised version of 304 with a controlled higher carbon content. The “H” means high carbon, within 0.04% to 0.10%.
Two features set the grade apart:
- Niobium stabilisation: niobium ties up carbon as stable carbides, so chromium stays in solution. That prevents sensitisation, the chromium loss at grain boundaries that causes intergranular corrosion after welding or long heat exposure.
- Higher carbon: the extra carbon, combined with a solution anneal at a higher temperature, gives a coarser grain and better creep strength at temperatures above about 540 °C.
The result is a pipe that works in hot service where 304L and 316L soften, and where 304H or 321H can lose stability. In refineries, 347H is also widely used because it resists polythionic acid stress corrosion cracking. Pipes are ordered by nominal pipe size (NPS) and schedule.
Stainless Steel 347H Pipes
High-quality Stainless Steel 347H Pipes manufactured for demanding industrial applications across chemical, petrochemical, oil & gas, power generation, pharmaceutical, marine, construction and engineering industries. Available in various sizes, wall thicknesses and specifications, conforming to ASTM A312 TP347H and applicable ASME standards.
Types of Stainless Steel 347H Pipes
As a Stainless Steel 347H Pipes Manufacturer, we offer different pipe types to meet the needs of high-temperature industrial applications. Our range includes seamless and welded pipes, along with options for different wall thicknesses, dimensions, and finishes based on project specifications.
- Stainless Steel 347H Seamless Pipes: Made without welded joints for high-temperature process lines and demanding industrial service.
- Stainless Steel 347H Welded Pipes: Available for piping systems that require specific diameters, wall thicknesses, and welded construction.
- Stainless Steel 347H Heavy Wall Pipes: Supplied in selected schedules for applications that require thicker pipe walls.
- Stainless Steel 347H Large Diameter Pipes: Suitable for industrial systems that need larger pipe dimensions for fluid or gas transport.
- Stainless Steel 347H Custom-Length Pipes: Cut to specified lengths to meet installation and fabrication requirements.
- Stainless Steel 347H Bevelled-End Pipes: Prepared with bevelled ends to support welding and pipe installation.
- Stainless Steel 347H Polished Pipes: Available with selected surface finishes according to application and project needs.
We supply Stainless Steel 347H Pipes in different sizes, schedules, and specifications to meet the requirements of refineries, petrochemical plants, power stations, and other high-temperature applications.
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→Get Certified Stainless Steel 347H Pipes at Competitive Factory Prices
Stainless Steel 347H Pipes Specification
| Item | Detail |
|---|---|
| Product | Stainless Steel 347H Pipes |
| Grade | 347H (UNS S34709, 1.4912) |
| Process | Seamless (hot finished or cold drawn) or welded, then solution annealed |
| Pipe standards | ASTM A312 / ASME SA312, ASTM A376 / ASME SA376 (seamless), ASTM A358 (welded), EN 10216-5 |
| General requirements | ASTM A999 |
| Dimensions | ASME B36.19M (Sch 10S, 40S, 80S), ASME B36.10M (Sch 160 and other walls) |
| Size reference | NPS 1/2 to 12 in the tables, other sizes on request |
| Length | Single random, double random or cut length |
| Ends | Plain or bevelled (ASME B16.25) |
| Heat treatment | Solution annealed at a higher temperature for coarse grain |
| Surface | Pickled and passivated |
| Tests | Chemical analysis, tensile, hardness, flattening, hydrostatic or non-destructive test; intergranular corrosion test on request |
| Certificate | EN 10204 3.1 with every order, 3.2 on request |
| Inspection | Third-party inspection on request |
Stainless Steel 347H Pipes Standards and Specifications
Pipe for hot service is bought to a pipe standard, with matching fittings and design codes behind it. The table links each one to its job.
| Standard | Covers | Applies to |
|---|---|---|
| ASTM A312 / ASME SA312 | Seamless, welded and heavily cold-worked austenitic stainless steel pipe | Core 347H pipe standard |
| ASTM A376 / ASME SA376 | Seamless austenitic steel pipe for high-temperature central-station service | Power plant hot piping |
| ASTM A358 | Electric-fusion-welded austenitic chromium-nickel stainless steel pipe for high-temperature service | Welded 347H pipe |
| ASTM A409 | Welded large-diameter austenitic steel pipe for corrosive or high-temperature service | Large-diameter pipe |
| ASTM A999 | General requirements for alloy and stainless steel pipe | Tolerances and test rules |
| EN 10216-5 | Seamless stainless steel tubes for pressure purposes | European grade 1.4912 |
| ASTM A403 | Wrought austenitic stainless steel piping fittings | Matching butt-weld fittings (WP347H) |
| ASTM A182 | Forged fittings and flanges, F347H | Matching forgings |
| ASME B31.1, B31.3 | Power piping and process piping design | Pipe design |
| ASME Section II, Part D | Allowable stress values by temperature | Wall thickness calculation |
| ASME B36.19M and B36.10M | Pipe dimensions and weights | OD and wall reference |
| ASME B16.25 | Butt-welding ends | Bevel angle and root face |
| EN 10204 | Types of inspection documents | 3.1 and 3.2 certificates |
Stainless Steel 347H Pipes Material and Grades
Pick the grade by operating temperature and the risk of sensitisation. The table lists 347H with the related stabilised grades, with their UNS and EN numbers.
| Grade | UNS | EN number | Name | Typical use |
|---|---|---|---|---|
| 347H | S34709 | 1.4912 | X10CrNiNb18-9 | High-temperature creep service, refineries, power |
| 347 | S34700 | 1.4550 | X6CrNiNb18-10 | Corrosion service at moderate temperature |
| 348H | S34809 | — | Ta and Co limited 347H | Nuclear-related and special service |
| 321H (for reference) | S32109 | 1.4878 | X10CrNiTi18-10 | Titanium-stabilised alternative for hot service |
What Is the Difference Between Stainless Steel 347H Pipes and Stainless Steel 321H Pipes?
The short answer: 347H is stabilised with niobium and 321H with titanium. Both resist intergranular corrosion in hot service, but niobium survives welding better than titanium, so 347H is the more dependable choice for welded piping and for hot lines that see repeated heating. Use 321H where a project specification calls for it.
| Point | 347H Pipes | 321H Pipes |
|---|---|---|
| UNS | S34709 | S32109 |
| EN number | 1.4912 | 1.4878 |
| Stabilising element | Niobium | Titanium |
| Carbon | 0.04–0.10% | 0.04–0.10% |
| Stabilisation after welding | Holds well | Titanium can burn off in the arc |
| Creep strength | High | High |
| Polythionic acid cracking | Strong resistance | Good resistance |
| Tensile strength, min | 515 MPa | 515 MPa |
| Cost | Slightly higher | Slightly lower |
| Common standards | ASTM A312, A376, A358 | ASTM A312, A376, A358 |
| Typical use | Refinery, power, petrochemical hot lines | Hot lines, exhaust and heat treatment equipment |
Stainless Steel 347H Pipes Chemical Composition
Chemistry gives 347H its stability and creep strength. The table shows the ASTM A312 limits, one element per row. Values are percentage by weight, maximum unless shown as a range or marked "min".
| Element | 347 (S34700) | 347H (S34709) | 348H (S34809) |
|---|---|---|---|
| Carbon (C) | 0.08 | 0.04–0.10 | 0.04–0.10 |
| Manganese (Mn) | 2.00 | 2.00 | 2.00 |
| Phosphorus (P) | 0.045 | 0.045 | 0.045 |
| Sulphur (S) | 0.030 | 0.030 | 0.030 |
| Silicon (Si) | 1.00 | 1.00 | 1.00 |
| Chromium (Cr) | 17.0–19.0 | 17.0–19.0 | 17.0–19.0 |
| Nickel (Ni) | 9.0–13.0 | 9.0–13.0 | 9.0–13.0 |
| Niobium (Nb) | 10×C min, 1.00 max | 8×C min, 1.00 max | 8×C min, 1.00 max |
| Tantalum (Ta) | — | — | 0.10 |
| Cobalt (Co) | — | — | 0.20 |
Stainless Steel 347H Pipes Mechanical Properties
The table gives minimum values under ASTM A312, with typical physical data, one property per row.
| Property | 347 | 347H | 348H |
|---|---|---|---|
| Tensile strength, MPa (ksi) | 515 (75) | 515 (75) | 515 (75) |
| Yield strength 0.2%, MPa (ksi) | 205 (30) | 205 (30) | 205 (30) |
| Elongation (%) | 35 | 35 | 35 |
| Hardness, max | 90 HRB (192 HBW) | 90 HRB (192 HBW) | 90 HRB (192 HBW) |
| Density (g/cm³) | 7.96 | 7.96 | 7.96 |
| Melting range (°C) | 1400–1425 | 1400–1425 | 1400–1425 |
| Thermal conductivity at 100 °C (W/m·K) | 16.3 | 16.3 | 16.3 |
| Modulus of elasticity (GPa) | 193 | 193 | 193 |
Stainless Steel 347H Pipes Size and Weight Chart
Weight depends on OD and wall thickness. 347H has a density of about 7.96 g/cm³, so we use this formula:
OD and wall are in mm. Example: NPS 4 Sch 40S is (114.3 − 6.02) × 6.02 × 0.02501 = 16.30 kg/m. Multiply by length for total weight. Walls for each schedule are listed in the next section.
| NPS | OD (mm) | Sch 10S (kg/m) | Sch 40S (kg/m) | Sch 80S (kg/m) | Sch 160 (kg/m) |
|---|---|---|---|---|---|
| 1/2" | 21.3 | 1.01 | 1.28 | 1.64 | 1.97 |
| 1" | 33.4 | 2.12 | 2.54 | 3.28 | 4.30 |
| 2" | 60.3 | 3.99 | 5.51 | 7.59 | 11.27 |
| 3" | 88.9 | 6.55 | 11.45 | 15.49 | 21.65 |
| 4" | 114.3 | 8.49 | 16.30 | 22.64 | 34.01 |
| 6" | 168.3 | 14.02 | 28.66 | 43.17 | 68.52 |
| 8" | 219.1 | 20.25 | 43.15 | 65.56 | 112.85 |
| 10" | 273.1 | 28.18 | 61.17 | 82.71 | 174.78 |
| 12" | 323.9 | 36.50 | 74.93 | 98.85 | 242.15 |
Available Sizes, Dimensions and Schedules
Stainless Steel 347H Pipes follow ASME B36.19M for Sch 10S, 40S and 80S, and ASME B36.10M for Sch 160. A schedule is a wall-thickness code, so for the same OD a higher number means a thicker wall. Hot piping is often designed from the allowable stress at temperature, so confirm the wall against the design code. Other sizes and walls can be quoted on request.
| NPS | OD (mm) | Sch 10S (mm) | Sch 40S (mm) | Sch 80S (mm) | Sch 160 (mm) |
|---|---|---|---|---|---|
| 1/2" | 21.3 | 2.11 | 2.77 | 3.73 | 4.78 |
| 1" | 33.4 | 2.77 | 3.38 | 4.55 | 6.35 |
| 2" | 60.3 | 2.77 | 3.91 | 5.54 | 8.74 |
| 3" | 88.9 | 3.05 | 5.49 | 7.62 | 11.13 |
| 4" | 114.3 | 3.05 | 6.02 | 8.56 | 13.49 |
| 6" | 168.3 | 3.40 | 7.11 | 10.97 | 18.26 |
| 8" | 219.1 | 3.76 | 8.18 | 12.70 | 23.01 |
| 10" | 273.1 | 4.19 | 9.27 | 12.70 | 28.58 |
| 12" | 323.9 | 4.57 | 9.53 | 12.70 | 33.32 |
Tolerances on OD, wall and length follow ASTM A999 and the product standard, and they depend on pipe size.
Common Materials Supplied with Stainless Steel 347H Pipes
Different materials and piping components are needed for high-temperature systems, depending on operating conditions, welding requirements, and corrosion risks. Our supply range includes Stainless Steel 347H and related grades and components for industrial piping projects.
Stainless Steel 347H (UNS S34709): A high-carbon, niobium-stabilised grade designed for strength during prolonged exposure to elevated temperatures.
Stainless Steel 347 (UNS S34700): A stabilised stainless steel grade suitable for corrosion-resistant applications and moderate-temperature service.
Stainless Steel 348H (UNS S34809): A high-carbon, stabilised grade used in specialised applications with tighter limits on certain elements.
WP347H Pipe Fittings and F347H Flanges: Matching components, including elbows, tees, reducers, and flanges, for compatible piping systems.
ER347 and E347 Welding Filler Materials: Used for welding compatible 347-series stainless steel components.
As experienced Stainless Steel 347H Pipes Suppliers, we support industrial orders with suitable material options, pipe dimensions, schedules, and finishes based on project specifications. Material selection depends on the required temperature range, mechanical properties, and applicable standards.
Stainless Steel 347H Pipes We Manufacture and Supply
We make Stainless Steel 347H Pipes for the high-temperature jobs below. The form and wall follow the pressure and the temperature.
| Service | Typical form | Typical wall |
|---|---|---|
| Refinery hydrotreater and FCC lines | Seamless | Sch 40S to 160 |
| Power plant steam and superheater piping | Seamless | Sch 80S to 160 |
| Heat recovery steam generator piping | Seamless or welded | Sch 40S to 80S |
| Petrochemical furnace and heater piping | Seamless | Sch 40S to 160 |
| Flue gas and exhaust ducting | Welded | Sch 10S to 40S |
| High-temperature chemical process lines | Seamless or welded | Sch 10S to 80S |
Applications of Stainless Steel 347H Pipes
- Oil refineries: hydrotreater, hydrocracker and FCC piping, where polythionic acid cracking is a risk.
- Power generation: steam, superheater and reheater piping in utility boilers.
- Heat recovery steam generators: high-temperature gas and steam lines.
- Petrochemical plants: furnace outlets, heater coils and high-temperature process lines.
- Fertiliser and ammonia plants: hot process and waste-heat lines.
- Chemical processing: hot, corrosive lines that run at high temperature.
- Waste incineration: hot gas and flue lines.
- Heat treatment plants: furnace and exhaust piping.
- Gas turbine systems: exhaust and high-temperature ducting.
Why Choose Us as Your Stainless Steel 347H Pipes Manufacturer in India?
Since 2005, we have built experience in manufacturing, supplying, and exporting industrial pipes and tubes for a wide range of applications. We supply Stainless Steel 347H Pipes in different outside diameters, wall thicknesses, and schedules to meet project requirements. With a monthly supply capacity of up to 100 tons, we can support bulk orders and ongoing industrial projects. Our experience also helps us understand the material requirements of refineries, petrochemical plants, and power generation facilities.
Quality checks and proper documentation are important for high-temperature piping materials. We provide EN 10204 3.1 mill test certificates with orders, while EN 10204 3.2 certification and third-party inspection can be arranged when required. Our certifications include ISO 9001:2015, ISO 14001:2015, and ISO 45001:2018, along with applicable PED and TÜV approvals. As a Stainless Steel 347H Pipes Supplier in India, we also support international orders with export packing, shipping documents, and delivery coordination to customers in 85+ countries.
Countries We Export Stainless Steel 347H Pipes To
We supply Stainless Steel 347H Pipes to industrial customers across 85+ countries, supporting projects that require materials for high-temperature operations. Our export services cover different pipe sizes, wall thicknesses, and specifications for refineries, petrochemical plants, power stations, and other industrial facilities. We coordinate each order according to its technical requirements and destination.
Middle East: UAE, Saudi Arabia, Qatar, Oman, Kuwait, and Bahrain.
Europe: Germany, Italy, France, the United Kingdom, the Netherlands, Spain, Belgium, and Poland.
Asia-Pacific: Japan, South Korea, Singapore, Malaysia, Indonesia, Thailand, Vietnam, and Australia.
North and South America: USA, Canada, Mexico, Brazil, and Chile.
Africa: South Africa, Egypt, Nigeria, and Kenya.
South Asia: Bangladesh, Nepal, and Sri Lanka.
For international orders, we arrange suitable export packing and provide material test certificates and shipping documents according to the order requirements. Third-party inspections and additional certification can also be coordinated when specified. Our experience in international supply helps ensure that Stainless Steel 347H Pipes are prepared for shipment with the documentation needed for inspection, customs clearance, and project records.
FAQs
Common questions about Stainless Steel 347H pipes, niobium stabilisation, welding and supply.
What is the difference between 347H and 321H?
347H is stabilised with niobium, while 321H is stabilised with titanium. Niobium survives welding better, so 347H is often preferred for welded hot-service piping.
Why use 347H instead of 347?
347H has a controlled carbon range of 0.04–0.10% and a coarse grain structure, giving better creep and stress-rupture resistance for long service at high temperature.
What filler metal is used for 347H welding?
ER347 or E347 filler is commonly used. The final selection must follow the qualified welding procedure and the applicable code.
Does 347H need post-weld heat treatment?
Usually no. Its niobium stabilisation helps resist sensitisation, but the welding procedure and design code decide whether any heat treatment is required.
How do I calculate the weight of 347H pipe?
Use (OD − Wall) × Wall × 0.02501, with both values in mm, to get kg per metre. Multiply by length for total weight.
Which documents come with an order?
EN 10204 3.1 mill test certificates are included. EN 10204 3.2 certification, IGC reports and third-party inspection are available on request.