GOST 28759.5-90 PDF

Full title and description

GOST 28759.5-90 — "Flanges of vessels and apparatus. Technical requirements" (ГОСТ 28759.5-90). The standard sets technical requirements for manufacture, dimensional tolerances, surface and assembly requirements for steel flanges used on vessels and apparatus in chemical, petrochemical and related industries.

Abstract

This short standard specifies basic technical requirements for steel flanges of vessels and apparatus, including permissible dimensional and positional tolerances for bolt holes and diameters, flatness and coaxiality limits, preparation of weld ends and requirements for sealing surfaces and gaskets. It was issued under the GOST system and later superseded by updated GOST series documents in 2022.

General information

• Status: Withdrawn / replaced; superseded by a later revision in the GOST 28759 series (GOST 28759.5-2022 and related parts).
• Publication date: Designation year 1990 (suffix -90); listed as withdrawn/invalid on 1 January 1992 in public catalogues.
• Publisher: Issued under the Soviet/Russian state standards system (Gosstandart at time of issue; maintained subsequently within the Rosstandart system).
• ICS / categories: Pressure vessels and fluid storage / flanges (ICS related to pressure vessels and fluid storage devices, e.g., ICS 23.020 and subgroups).
• Edition / version: GOST 28759.5-90 (single edition under this designation); later superseded by the 2022 revision of the GOST 28759 series.
• Number of pages: 4 pages (short technical standard).

Scope

The standard applies to steel flanges for vessels and apparatus intended for use in chemical, oil, petrochemical and other industrial sectors, specifying construction-related technical requirements (dimensions, tolerances, surface and assembly requirements) for flanges used on welded and fabricated vessels and equipment.

Key topics and requirements

• Dimensional ranges and nominal sizes for flange elements (bolt circle, bore, raised face and other relevant diameters).
• Positional and dimensional tolerances for bolt holes (positional tolerance limits and limits for angular spacing).
• Flatness and coaxiality limits for sealing and flange faces (specified maximum deviations for face flatness and concentricity between key diameters).
• Requirements for prepared weld edges, weld seams and reference to applicable welding standards and procedures.
• Surface finish and gasket seating provisions, including allowable surface irregularity and recommended gasket types (including gaskets in metal envelopes in related parts of the series).
• Reference tolerances for holes and shafts where not otherwise specified (standard tolerance grades indicated in the text).

Typical use and users

Used historically by designers, fabricators and inspectors of pressure vessels and process equipment in chemical, petrochemical, oil refining and related heavy industries to ensure interchangeability and reliable sealing of flanged connections. Today engineers consult the replaced/superseding 2022 series for current requirements.

Related standards

Part of the broader GOST 28759 family (other parts cover construction and dimensions of welded flanges, gaskets in metal envelopes, and related items). The classic GOST flange/dimension standards such as GOST 12820-80 and other GOST parts for flanges and fittings are also relevant when working with Russian-style flange systems. For up-to-date requirements, consult the GOST 28759.* 2022 series that superseded earlier editions.

Keywords

GOST 28759.5-90; flanges; vessels and apparatus; flange tolerances; bolt holes; flatness; coaxiality; welding preparation; chemical industry; petrochemical; withdrawn; superseded.

FAQ

Q: What is this standard?

A: GOST 28759.5-90 is a short technical standard titled "Flanges of vessels and apparatus. Technical requirements" that specified dimensional and manufacturing requirements for steel flanges used on vessels and process equipment.

Q: What does it cover?

A: It covers technical requirements such as permissible dimensional and positional tolerances for bolt holes and diameters, face flatness and coaxiality limits, weld preparation and surface/sealing provisions for flanges on vessels and apparatus.

Q: Who typically uses it?

A: Designers, manufacturers, welders and inspectors of pressure vessels and process equipment in the chemical, petrochemical, oil refining and related industries—historically within the USSR/Russia and by organizations working with GOST-compatible equipment.

Q: Is it current or superseded?

A: The -90 edition has been withdrawn/declared invalid in catalogues (listed as withdrawn 1 January 1992) and has been superseded by newer documents in the GOST 28759 series (notably the 2022 revisions for the relevant parts). For current requirements use the 2022 series or the active national standard texts.

Q: Is it part of a series?

A: Yes — it is one part of the GOST 28759 family (multiple parts cover flange construction, dimensions and related items including gasket types). The series has been updated and reorganized in recent revisions (2022 series).

Q: What are the key keywords?

A: Flanges, vessels, apparatus, technical requirements, tolerances, bolt holes, flatness, coaxiality, welding, GOST, GOST 28759.5-90.