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Utilizing 26 high-precision cold rolling mills and 6 cold drawing machines, we ensure dimensional accuracy and superior mechanical properties.
Heavy Wall Stainless Steel Pipes
ASTM A312 / A790 | Sch 80S to XXH & Custom | TP316L / S32205 / S32750 | High Pressure Rated
ISO 9001 | ASME B31.3 | 100% UT TestedRelated Products
Introduction
At the demanding frontier of high-pressure process engineering, where operating pressures in chemical reactors, hydraulic intensifier systems, subsea wellhead infrastructure, and supercritical fluid processing equipment push against the fundamental limits of conventional pipe wall thickness, the engineering community relies on a specialized category of stainless steel pipe products that transcends the dimensional scope of standard schedule piping: Heavy Wall Stainless Steel Pipes, characterized by wall thickness-to-outside-diameter ratios substantially exceeding those of standard pipe schedules, provide the pressure containment capability, structural rigidity, and mechanical integrity required for the most demanding pressure applications in global industrial and energy infrastructure. Defined here as seamless stainless steel pipes with wall thicknesses exceeding Schedule 80S and typically representing D/t ratios below 10 (where standard process piping commonly operates at D/t ratios of 15–30), heavy wall stainless pipes are produced through specialized thick-wall hot extrusion and heavy-reduction cold-drawing processes that achieve the combination of dense, defect-free microstructure and precise dimensional control required to exploit the full mechanical potential of the austenitic, duplex, and super duplex stainless grades specified for the highest-pressure applications. The pressure ratings achievable with heavy wall stainless pipe — reaching 2,000 bar and above for small diameter Schedule 160 and custom heavy-wall configurations in high-strength duplex grades — create application capabilities that extend far beyond the envelope of standard stainless process piping and place heavy wall stainless pipe in direct competition with alloy steel pressure tubing for applications where corrosion resistance is required simultaneously with extreme pressure containment.
The pressure-containing capability of heavy wall stainless steel pipes is governed by the fundamental relationship between pipe geometry (OD and wall thickness), material yield strength, and the applicable pressure vessel or piping design code — ASME B31.3 for process piping, ASME Section VIII Division 2 for high-pressure vessels, ISO 13628 for subsea equipment, or NORSOK standards for Norwegian offshore applications. For thick-wall pipes where the wall thickness exceeds approximately 10% of the inside radius, the simplified thin-wall Barlow's formula progressively underestimates actual hoop stress, and the more complex Lamé thick-cylinder equations must be applied to correctly calculate maximum allowable working pressure — a distinction that becomes design-critical when wall thickness reaches 25–50% of the pipe OD in extreme high-pressure applications. The selection of austenitic versus duplex versus super duplex grade for heavy wall stainless pipe applications is driven primarily by this pressure-rating calculation: the higher yield strength of duplex S32205 (minimum 450 MPa) relative to austenitic TP316L (minimum 170 MPa) allows equivalent pressure ratings to be achieved with substantially thinner walls, reducing material cost and improving heat transfer efficiency in high-pressure heat exchanger applications where both pressure containment and thermal performance are design objectives.
The manufacturing of heavy wall stainless steel pipe presents technical challenges that distinguish it fundamentally from standard schedule pipe production and that require specialized production capability not universally available in the global stainless pipe manufacturing industry. The hot extrusion of thick-wall billets requires higher extrusion forces and more precisely controlled temperature profiles than thin-wall pipe production to ensure that the dense, defect-free microstructure required for pressure service is achieved throughout the full wall thickness, including the wall center zone that is most distant from the pipe surface and therefore most susceptible to microstructural defects arising from inadequate hot reduction or insufficient recrystallization during the extrusion thermal cycle. The subsequent heavy-reduction cold-drawing passes required to achieve final dimensions and mechanical properties in the cold-finished condition require carefully designed multi-pass schedules with intermediate solution annealing treatments to restore ductility consumed by cold work hardening, preventing the premature cracking of the thick-wall cross-section during cold reduction that would occur if the cold work reduction were applied without intermediate annealing. Our heavy wall pipe production capability, anchored in specialist extrusion presses and heavy-reduction cold-drawing equipment with full in-process ultrasonic testing capability, ensures consistent through-wall structural quality in the finished heavy wall pipe product.
Our heavy wall stainless steel pipe program covers outside diameters from 21.3mm (NPS 3/4) to 273mm (NPS 10) with wall thicknesses from Schedule 80S through Schedule 160, XXH (double extra heavy), and custom heavy-wall configurations with D/t ratios as low as 3:1 for extreme pressure applications. Available grades span TP316L, TP321, duplex S32205, super duplex S32750, and 6Mo super austenitic S31254, with ASME B31.3 pressure-temperature ratings calculated for each grade-dimension combination. All heavy wall pipes are 100% ultrasonically tested per ASTM E213 for volumetric defect detection throughout the full wall thickness, supplemented by hydrostatic pressure testing at 1.5× design pressure. Complete EN 10204 3.1 material certification with actual tensile, yield, and elongation test results, hardness verification, and chemical analysis is standard. Our pressure engineering team provides ASME B31.3 and ASME VIII Division 2 pressure rating calculations for specific design conditions, supporting project engineering teams in material and wall thickness optimization for high-pressure stainless pipe system design.
Specifications
| Available Grades | TP316L, TP321, S32205, S32750, S31254 |
| Standard | ASTM A312, A790, EN 10216-5 |
| Outer Diameter | 21.3mm - 273mm (NPS 3/4" to 10") |
| Wall Thickness | Sch 80S to XXH, Custom D/t ≥ 3:1 |
| Length | Up to 12000mm (Random or Fixed) |
| NDE | 100% UT + Hydrostatic at 1.5× Design Pressure |
Chemical Composition (S32205 Duplex)
| Element | C | Cr | Ni | Mo | N | Mn | Si |
| Value (%) | ≤0.030 | 22.0-23.0 | 4.5-6.5 | 3.0-3.5 | 0.14-0.20 | ≤2.00 | ≤1.00 |
Up to 2000 bar Rated100% UT InspectionASME B31.3 Rated
Mechanical Strength (S32205)
Comprehensive Info
| MOQ | 500kg (Negotiable for custom heavy wall) |
| Lead Time | 25 - 50 Days |
| Packaging | Heavy-Duty Plywood Crates / Steel Banding |
| Certifications | ISO 9001, ASME B31.3, PED |
| Raw Materials | Premium Billet Quality Duplex / Austenitic Melt |
| Customization | Grade, OD/WT, D/t Ratio, Pressure Rating Calc |
Applications
High-Pressure Hydraulic SystemsDuplex S32205 heavy wall pipe for 400–700 bar hydraulic intensifier and high-pressure water injection pump discharge lines
Subsea Wellhead & Manifold BodiesSuper duplex S32750 heavy wall pipe for deepwater wellhead cross-over spools and subsea manifold structural piping rated to 10,000 psi
Supercritical Fluid ExtractionTP316L heavy wall pipe for supercritical CO₂ extraction systems operating above 200 bar in pharmaceutical and food processing applications
High-Pressure Chemical ReactorsHeavy wall austenitic pipe for autoclave feed and discharge lines in high-pressure polymerization, hydrogenation, and synthesis reactor systems
Supercritical Steam Boiler PipingTP321 heavy wall pipe for supercritical and ultra-supercritical steam generator main steam lines operating above 250 bar
HP/HT Downhole CompletionS32750 super duplex heavy wall pipe for high-pressure high-temperature downhole completion and production tubular applications
Advantages
Extreme Pressure Capability
D/t ratios as low as 3:1 in duplex and super duplex grades achieve pressure ratings exceeding 2,000 bar — enabling stainless corrosion resistance in applications previously requiring non-corrosion-resistant alloy steel for pressure containment.
100% Volumetric UT Testing
Full-length ultrasonic testing of every heavy wall pipe detects internal laminations, inclusions, and voids through the complete wall thickness — the critical QA requirement for thick-wall pressure pipe where surface-only inspection cannot detect mid-wall defects.
Pressure Rating Engineering Support
ASME B31.3 and ASME VIII Division 2 pressure-temperature rating calculations provided for each grade-dimension combination — supporting project engineers in code-compliant heavy wall pipe system design from material selection through final pressure rating documentation.
Grade Strength Optimization
S32205 and S32750 duplex grades achieve pressure ratings equivalent to austenitic TP316L at approximately 40–60% reduced wall thickness — directly reducing pipe weight, support structure loading, and total installed cost in high-pressure stainless piping systems.
About Jiangsu Jend Tube Co.,Ltd.
As China Heavy Wall Stainless Steel Pipes Manufacturers and Wholesale Heavy Wall Stainless Steel Pipes Factory, Established in 2011 and is a manufacturing enterprise with a complete manufacturing cycle from raw material selection to finished product delivery. The company currently has more than 100 employees, covers an area of 30015 square meters, and has a registered capital of 48 million yuan, annual production capacity of 3800 tons.
The company has passed ISO9001:2015 quality certification, domestic pressure vessel TS certification, and foreign pressure vessel PED certification. With rich experience and mature technology, we have been expanding our market internationally. At present, our products are exported to more than 50 countries and regions including Europe, America, Southeast Asia, and the Middle East.
The company adheres to different production norms and standards such as the American standard (ASTM), the European standard (EN), the German standard (DIN), the Japanese standard (JIS), the Russian standard (GOST), and the Chinese standard (GB).
Our company specializes in and customizes various specifications of Martensite TP410 (0Cr13, 1Cr13), Ferrite TP405 (1Cr13Al), TP430 (1Cr17), TP444 (0Cr18Mo2), TP439, TP409 (0Cr11Ti), It is also proficient in manufacturing Austenitic seamless stainless steel pipes of series such as TP304(L/H), TP316(L/H/Ti), TP310S, TP317, TP321(H) and TP347(H). Duplex such as S31803, S2205, S32750, S32304, and Nickel-based alloys Monel400, Monel600, Monel800, GH3030, 904L, Inconel 625, etc.
The company mainly produces seamless steel pipes with the following specifications: outer diameter: 3.18mm to 406.4mm, wall thickness: 0.3mm to 20mm, and the longest length is 25000mm. Additionally, it can customize seamless steel pipes with special materials and specifications according to customer requirements. The company attaches great importance to scientific innovation. The staff of the company vigorously develop technological research and development.
Jiangsu Jend Tube Co.,Ltd. will continuously accumulate professional knowledge and capabilities, striving to become a leader in the domestic market and even the world market. Strive to be the most reassuring pipe manufacturing enterprise for customers.
Precision Manufacturing and Process Optimization
We rely on precision equipment and optimized production technologies to achieve outstanding mechanical performance and consistent product quality.
Cold Rolling and Cold Drawing
Solution Heat Treatment
Natural gas solution treatment furnaces and BA solution treatment furnaces optimize the material's grain structure, enhancing corrosion resistance.
Precision Straightening and Polishing
10 straightening machines and 8 finishing polishing machines guarantee product surface smoothness and dimensional accuracy.
Automated Inspection and Quality Assurance
Real-time monitoring systems ensure the stable quality of every batch of products.
Product Usage Tips
Thick-Wall Pressure Rating
For heavy wall pipe where t/r > 0.1 (wall thickness exceeds 10% of internal radius), use Lamé thick-cylinder formula: P = 2S × t/(D − t) rather than Barlow's thin-wall approximation. For D/t ratios below 6:1, the Barlow formula overestimates burst pressure by 5–15% — a non-conservative error that can lead to under-sized wall thickness specification for the required design pressure with the applicable safety factor.
Welding Heavy Wall Stainless Pipe
For heavy wall stainless pipe welds, use multi-pass TIG root pass with SMAW or SAW fill and cap passes for efficiency on thick sections. Control interpass temperature below 150°C for austenitic grades and below 100°C for duplex grades to prevent sigma phase precipitation. For duplex heavy wall pipe above 25mm wall, perform ferrite content verification per ASTM E562 on weld cross-sections to confirm the 35–65% ferrite target range is maintained throughout the full weld deposit thickness.
UT Inspection Calibration
For heavy wall pipes above 20mm wall thickness, calibrate ultrasonic testing equipment using reference reflectors at 1/4T, 1/2T, and 3/4T depths to ensure sensitivity is maintained throughout the complete wall cross-section. Single-surface calibration adequate for thin-wall tube is insufficient for heavy wall pipe UT — mid-wall defects may be missed if the UT sensitivity is calibrated only for near-surface reflection geometry.
Duplex Phase Balance in Heavy Wall
For duplex heavy wall pipe sections above 30mm wall, validate that the solution annealing heat treatment achieves uniform temperature throughout the full wall cross-section by thermocouple verification or metallographic ferrite content examination on wall cross-section samples. Insufficient heat treatment of thick-wall duplex pipe creates sigma phase in the wall center region that is not detected by surface hardness measurement but severely embrittles the material in service.
Value-Added Processing Services
We provide comprehensive heavy wall pipe processing for high-pressure chemical, subsea, and offshore applications:
End Preparation
ASME B16.25 weld-end bevel machining with dimensional verification — critical for consistent root gap in heavy wall multi-pass welds.
100% UT + Hydrostatic
Combined volumetric UT and hydrostatic testing at 1.5× design pressure with individual pipe test records for every length.
ASME Pressure Rating Calc
ASME B31.3 and VIII Div.2 thick-wall pressure rating calculations with code-stamped engineer sign-off for project documentation.
Ferrite Content Verification
Duplex ferrite content measurement per ASTM E562 on weld and base metal cross-sections for phase balance qualification.
Payment & Shipping
Payment Terms
- T/T (Telegraphic Transfer)
- L/C at Sight (Letter of Credit)
- Western Union
- Flexible terms for long-term partners
Shipping Options
- Sea Freight (FCL/LCL)
- Air Freight for urgent orders
- Express for small samples
- Heavy-duty steel-banded plywood crates for oversized heavy wall sections
Certifications & Standards
Our heavy wall stainless steel pipes are certified to international high-pressure piping and pressure vessel standards:
ISO 9001:2015
ASME B31.3
ASME VIII Div.2
ASTM A312 / A790
PED Certification
EN 10204 3.1 MTR
Frequently Asked Questions
What wall thickness qualifies as "heavy wall" stainless pipe?
Heavy wall stainless pipe is typically defined as wall thickness exceeding ASME B36.19 Schedule 80S — the heaviest standard schedule — for a given OD, or D/t ratios below approximately 10:1. In practice, our heavy wall program covers Sch 80S through XXH and custom thick-wall configurations designed to specific pressure-temperature rating requirements rather than standard schedule dimensions.
Why is duplex S32205 preferred over TP316L for high-pressure stainless pipe?
S32205 duplex has a minimum yield strength of 450 MPa versus TP316L's 170 MPa — allowing equivalent ASME B31.3 pressure ratings to be achieved with approximately 40% reduced wall thickness. The thinner wall reduces pipe weight, material cost, and heat exchanger wall thermal resistance, while maintaining or improving corrosion resistance compared to TP316L in most process environments.
Is 100% ultrasonic testing mandatory for heavy wall stainless pipe?
ASTM A312 does not mandate UT as a standard requirement, but for pressure-critical heavy wall applications we specify 100% longitudinal and transverse ultrasonic testing per ASTM E213 as a supplementary requirement. This volumetric inspection is essential for heavy wall pipe where mid-wall laminations, inclusions, or voids that could cause catastrophic pressure failure cannot be detected by hydrostatic pressure testing or surface NDE methods alone.
What is the maximum pressure rating achievable with stainless heavy wall pipe?
For S32750 super duplex in 2" OD × 20mm WT (D/t ≈ 2.5:1) configuration, ASME B31.3 allowable pressure at ambient temperature exceeds 2,000 bar. For TP316L in equivalent dimensions, the lower yield strength limits the rating to approximately 800 bar. Exact pressure ratings depend on the specific OD, wall thickness, grade, operating temperature, and the applicable design code safety factor — contact our engineering team for project-specific calculations.
Can heavy wall duplex pipe be cold bent?
Cold bending of duplex heavy wall pipe is technically possible but requires careful control of bend radius (minimum 5× OD), bending speed, and post-bend ferrite content verification to confirm that cold work has not disrupted the austenite-ferrite phase balance. For critical pressure applications, induction hot bending with post-bend solution annealing is preferred to ensure full phase balance restoration and compliance with pressure design code mechanical property requirements in the bent region.
Do you provide ASME B31.3 pressure rating documentation?
Yes, ASME B31.3 process piping allowable pressure calculations for each grade-dimension combination are provided as standard engineering support for heavy wall pipe orders. For ASME Section VIII Division 2 high-pressure vessel applications, thick-cylinder allowable pressure calculations with code-referenced design basis are available from our pressure engineering team with the order documentation package.
What is the typical lead time for custom heavy wall stainless pipe?
Standard schedule heavy wall pipe (Sch 80S, 160) in common grades and dimensions is available within 25–35 days. Custom heavy wall dimensions with non-standard D/t ratios require billet sourcing and dedicated extrusion production, with lead times of 40–60 days. For urgent project requirements, contact our team for current billet stock status and accelerated production feasibility assessment.
Do you supply heavy wall stainless pipe for subsea applications?
Yes, we supply super duplex S32750 and S32760 heavy wall pipe for subsea wellhead, manifold, and flowline applications with NACE MR0175 sour service qualification, DNV-ST-F101 compliance documentation, and 100% UT plus hydrostatic testing to the elevated test pressures required by subsea pressure containment qualification programs.
Ready to Order Heavy Wall Stainless Steel Pipes?
Extreme pressure rating, 100% UT certified, ASME B31.3 engineering support — contact us for high-pressure stainless pipe solutions
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