GOST 28919-91 PDF

Full title and description

GOST 28919-91 — "Flange connections of wellhead equipment. Types, basic parameters and dimensions". The standard specifies types, main parameters, dimensional series and constituent parts (flanges, ring gaskets of octagonal cross‑section, studs and nuts) for high‑pressure wellhead (ustyevoe) flange connections used in oil and gas production.

Abstract

GOST 28919-91 establishes two principal types of flange connections (with and without a gap between flange faces), pressure classes and nominal diameters for wellhead flange assemblies, plus recommended technical requirements and mandatory designation rules for flanges, gaskets, studs and nuts used on production wellheads. It applies to connections designed for working pressures from 14 to 140 MPa and nominal diameters from 50 to 680 mm.

General information

• Status: Active (in force).
• Publication date: Original approval 1991; effective from 1 July 1992.
• Publisher: Межгосударственный стандарт / Издательство стандартов (state standards body; original USSR / interstate standard).
• ICS / categories: OKС / industry classification for oil/gas equipment (listed under pipeline and wellhead equipment — related code 75.180.10 in catalogs).
• Edition / version: GOST 28919-91 (1991) — original edition; includes later amendments (notably a change adopted by the Interstate Council in 2011 with entry into force on the Russian territory in 2012).
• Number of pages: 29 pages (standard text).

Scope

The standard covers flange connections for wellhead (ustyevoe) oil‑field equipment that use steel ring gaskets of octagonal cross‑section and are intended for joining components of wellhead and downhole assemblies. Applicable working pressures are specified from 14 MPa up to 140 MPa and nominal diameters (Du) from 50 mm to 680 mm; the document also defines flanges, gaskets, studs and nuts, plus designation and dimensioning rules for each type and variant.

Key topics and requirements

• Definition of two main types of flange connections: Type 1 — with a gap between flange faces; Type 2 — without a gap. Two variants for each type: flange‑to‑flange and flange‑to‑body.
• Tables of main dimensions and parameters (nominal diameters, bolt circle, number and size of studs/nuts, gasket cross‑section codes and masses).
• Design pressure classes and corresponding dimensional series covering 14, 21, 35, 70, 105 and 140 MPa (selection rules depend on Du and type).
• Technical requirements and recommended procedures for studs and nuts (mechanical properties, testing methods referenced to applicable fastener standards).
• Designation rules and mandatory marking/notation for flanges, gaskets and connection assemblies (conditional designations used in drawings and documentation).

Typical use and users

Used by designers and manufacturers of wellhead and Christmas tree equipment, oilfield equipment suppliers, flange and gasket producers, procurement and QA/QC departments in oil & gas companies, and engineering organisations involved in wellhead connection selection, fabrication and inspection. Typical applications include high‑pressure wellhead assemblies, adapters and transition spools for production and well testing.

Related standards

GOST 28919-91 cross‑references and works alongside other normative documents covering fastener testing and threads (for example nut testing standards and thread standards used on NKT threads), plus regional/interstate amendments and implementing documents. Implementing/testing references in practice include legacy GOST fastener test standards and their modern replacements (for example references to testing methods historically in GOST 1759.5 and more recent ISO/GOST harmonized documents).

Keywords

flange connections, wellhead equipment, flange dimensions, ring gasket, studs, nuts, high pressure, PN/MPa classes, Du (nominal diameter), GOST 28919-91.

FAQ

Q: What is this standard?

A: GOST 28919-91 is the Russian/interstate standard that defines types, basic parameters and dimensional series for flange connections of wellhead (ustyevoe) oilfield equipment, including flanges, octagonal ring gaskets, studs and nuts.

Q: What does it cover?

A: It covers two types of flange connections (with and without flange‑face gap), pressure classes from 14 to 140 MPa, nominal diameters from 50 to 680 mm, the dimensional tables for flanges and fasteners, gasket designations, and technical/marking requirements for assembly parts.

Q: Who typically uses it?

A: Designers, manufacturers and suppliers of wellhead and production tree equipment; procurement and QA/QC teams in oil & gas operators; fabricators and testing organisations that produce or verify flange connections and associated fasteners and gaskets.

Q: Is it current or superseded?

A: The standard is listed as in force (active). It was approved in 1991 and became effective 1 July 1992; later amendments (interstate change accepted in 2011) were recorded and implemented in national practice (entry into force dates set by national bodies, e.g., Russia 1 September 2012). Users should check their national standards catalog for the current status and any later revisions or replacements.

Q: Is it part of a series?

A: It is a standalone GOST for wellhead flange connections but is normally used together with related standards for fastener testing, thread standards and materials/heat‑treatment standards referenced in the technical requirements and appendices.

Q: What are the key keywords?

A: Flange, wellhead, ring gasket, studs, nuts, Du (nominal diameter), pressure class (MPa), flange face gap/type, dimensions.