Precision manufacturing of austenitic stainless steel stub ends for Russian Client

Recently, our workshop completed production of a batch of seamless stub ends tailored for a Russian customer with highly specific project requirements. This order demonstrated not only our capacity for precision manufacturing but also our experience in fulfilling detailed technical specifications and documentation standards.

ASTM A182 F44 seamless stub ends with smooth flange facing ready for shipment

Project Overview

The requested stub ends were designed and manufactured in full accordance with the client’s drawings and multiple international specifications. Below are the essential parameters:

Nominal Size: DN200 (203 mm length)

Wall Thickness: 3.76 mm (Schedule 10S)

Material: High-alloy austenitic stainless steel, ASTM A182M F44 (6Mo / UNS S31254)

Fitting Standard: ASTM A403M WP-S UNS S31254

Design Specification: ANSI/ASME B16.9 Table A7

Dimensional Reference: ANSI/ASME B36.10/19 (1985)

Manufacturing Process: Seamless forming

Finish: Smooth flange facing

This material grade (6Mo stainless) is selected for its excellent resistance to pitting and crevice corrosion in chloride-rich environments, making it suitable for offshore and process applications where conventional austenitic grades are inadequate.

Dimensional inspection of ASTM A403 WP S UNS S31254 stub ends at Haihao factory

Production and Inspection

Each stub end underwent a thorough production sequence:

Raw Material Sourcing:

We procured fully traceable ASTM A182M F44 billets from qualified mills, ensuring compliance with chemical composition and mechanical properties.

Seamless Forming:

The stub ends were shaped by cold forming and subsequent heat treatment to relieve internal stress and restore corrosion resistance.

Dimensional Verification:

Critical dimensions—including barrel length, wall thickness, and flange geometry—were measured against the design drawing and ASME B16.9 tolerances.

Surface Finish and Marking:

The flange faces were machined to a smooth finish suitable for butt welding, and all parts were permanently marked with material grade, schedule, and heat number.

Chemical composition inspection of ASTM A403 WP-S UNS S31254 stub ends at Haihao-factory

Documentation and Certification:

Per contract requirements, we prepared the following certificates and reports:

ISO 10474 3.1B Material Test Certificates (K09)

NACE compliance declaration for H2S service (K10)

CU TR Certificate of Conformity for pressure equipment (K40)

Packaging and Preservation

To meet the project’s stringent handling requirements, we applied a comprehensive preservation and packing plan:

• All metal surfaces were lightly oiled to prevent corrosion during transit.
• Each stub end was wrapped in watertight film.
• Components were packed in reinforced plywood crates.
• Desiccant sachets were included to control moisture.
• Flange seal surfaces were protected with temporary plywood caps to prevent mechanical damage.

This approach ensures the fittings remain in pristine condition during storage, transport, and site handling.

Meeting Complex Requirements

One of the challenges in this project was aligning the different references:

• DEP 30.10.02.35-EPE
• EXPRO MESC SPEC 76/504 and 76/005
• EXPRO ENG SPEC ES/311

These documents defined specific acceptance criteria beyond standard ASME or ASTM requirements. Our engineering and QA teams reviewed each clause to verify compliance, demonstrating our ability to manage multi-standard specifications in a single production batch.

Why It Matters to Clients

Many end users in oil & gas and chemical processing sectors face similar concerns:

• How to verify true material grade?
• Will all surfaces arrive free from corrosion and ready for welding?
• Can the supplier meet demanding certification and marking requirements?

By maintaining rigorous traceability and inspection processes, we help customers avoid costly rework, delays, and quality disputes.

If you need tailored fittings manufactured to international codes and customer specifications, our team is ready to assist. Email:sales@haihaogroup.com