BS 1640-4-1968 PDF

Full title and description

Specification for steel butt-welding pipe fittings for the petroleum industry — Wrought and cast austenitic chromium‑nickel steel fittings. Metric units. (BS 1640-4:1968)

Abstract

BS 1640-4:1968 defines dimensional, material, manufacturing, testing and marking requirements for wrought and cast austenitic chromium‑nickel (stainless) steel butt‑welding pipe fittings used in the petroleum industry. It covers sizes in metric units, lists permitted forms (elbows, tees, reducers, caps, lap‑joint stub ends and return bends), gives tolerances and workmanship requirements, and sets out inspection and test procedures appropriate to pressure/temperature ratings for piping systems in petroleum applications. The standard has been withdrawn/superseded by later EN standards.

General information

• Status: Withdrawn / Superseded
• Publication date: 21 March 1968
• Publisher: British Standards Institution (BSI)
• ICS / categories: 23.040 (Pipeline components and pipelines) — pipeline components / pipe fittings
• Edition / version: BS 1640-4:1968 (Part 4 — metric units)
• Number of pages: 16–20 (typical modern listings give 16 or 20 pages depending on format)

Scope

Applies to butt‑welding pipe fittings made from wrought and cast austenitic chromium‑nickel steels intended for use in the petroleum industry, specified in metric units. The scope includes dimensional requirements and tolerances, permitted materials and heat treatment, manufacturing methods, surface preparation (descaling), repair of defects, marking, inspection and testing requirements. Typical fitting types covered include 45° and 90° elbows (long and short radius), long‑radius tangent elbows, return bends, equal and reducing tees, concentric and eccentric reducers, caps and lap‑joint stub ends for nominal sizes generally from about DN19 up to DN609.5. The standard does not include welding‑neck flanges.

Key topics and requirements

• Definitions and size identification for butt‑welding fittings in metric units.
• Dimensional tables and tolerances for elbows, tees, reducers, bends, caps and stub ends (long and short radius forms).
• Material specification: wrought and cast austenitic chromium‑nickel steels (stainless grades) suitable for petroleum service.
• Manufacturing and heat‑treatment requirements, including descaling and permissible repair procedures.
• Workmanship and surface finish criteria.
• Pressure/temperature rating guidance appropriate to material and construction.
• Inspection, marking and testing requirements (visual, dimensional, mechanical and where applicable nondestructive examination and pressure testing).
• Cross‑references to related BSI items and national/industry material and piping standards.

Typical use and users

Used as a technical reference by piping designers, materials engineers, manufacturers of butt‑welding fittings (forged and cast stainless fittings), procurement and quality assurance teams in the petroleum, petrochemical and refinery sectors, and by inspectors and fabricators responsible for high‑integrity piping systems. Also referenced by standards librarians and technical authors for historical and cross‑reference purposes.

Related standards

Related items include other parts of the BS 1640 series (covering carbon and alloy steels and other forms), national and international piping‑fitting standards (for example BS 1600 — pipe dimensions, BS 1501 series, and later EN standards), and the EN replacement standards BS EN 10253 (parts that superseded the BS 1640 family). Equivalent or complementary standards from other systems include ASME/ANSI B16.9 and various MSS and ASTM material specifications used for stainless butt‑welding fittings.

Keywords

butt‑welding, pipe fittings, austenitic chromium‑nickel, stainless steel, petroleum industry, elbows, tees, reducers, metric units, dimensions, tolerances, inspection, testing, BS 1640

FAQ

Q: What is this standard?

A: BS 1640-4:1968 is a British Standard (Part 4 of BS 1640) that specified requirements for wrought and cast austenitic chromium‑nickel (stainless) butt‑welding pipe fittings in metric units for use in the petroleum industry.

Q: What does it cover?

A: It covers dimensions and tolerances, permitted materials and heat treatments, manufacturing and repair rules, marking, inspection and test procedures, and dimensional/pressure‑rating guidance for common butt‑weld fitting types (elbows, tees, reducers, caps, stub ends and return bends) in metric sizes.

Q: Who typically uses it?

A: Piping designers, flange and fitting manufacturers, quality/control inspectors, procurement specialists and engineers in the petroleum, petrochemical and refinery industries, and standards/technical libraries for reference or historical purposes.

Q: Is it current or superseded?

A: It has been withdrawn/superseded. The BS 1640 series has been replaced by later EN standards (for example the EN 10253 family) published in the 2000s; the BS 1640-4:1968 document itself is treated as superseded and is no longer the current normative reference for new procurement or design.

Q: Is it part of a series?

A: Yes — BS 1640 is a multi‑part series covering steel butt‑welding pipe fittings for the petroleum industry; Part 4 covers wrought and cast austenitic chromium‑nickel fittings (metric units). Other parts of the series address carbon and alloy steels and alternative unit systems.

Q: What are the key keywords?

A: Butt‑welding, pipe fittings, stainless steel, austenitic chromium‑nickel, petroleum, elbows, tees, reducers, metric dimensions, BS 1640.