OST 24.125.31-89 PDF
Name in English:
OST 24.125.31-89
Name in Russian:
ОСТ 24.125.31-89
Butt joint welds for NPP pipelines. Types and main dimensions
Full title and description
OST 24.125.31-89 — Butt joint welds for NPP pipelines. Types and main dimensions. (Russian title: ОСТ 24.125.31-89 — Швы сварные стыковых соединений трубопроводов АЭС. Типы и основные размеры.)
This industry (ОСТ) document defines standard types and principal geometric dimensions for butt-welded joints used in nuclear power plant (NPP) pipeline systems.
Abstract
OST 24.125.31-89 establishes standard forms (types) and main dimensional parameters for butt welds in pipelines used at nuclear power plants. The standard is oriented to welded butt joints in carbon and low-alloy steels commonly used in NPP piping and provides drawings, dimensional tables and reference notes necessary for design, fabrication and inspection of such welds.
General information
- Status: Historically issued OST (1989); available in commercial standards collections — repositories list the document as available/active while some catalogue entries show a formal end-of-validity date of 30 June 2003. Verify national registry for current formal status.
- Publication date: Approved 26 May 1989; introduced 1 January 1990 (designation suffix -89 indicates 1989 release).
- Publisher: Developed by NPO TsKTI named after I.I. Polzunov; approved by the USSR Ministry of Heavy, Power and Transport Engineering and adopted with participation/acceptance by Minatomenergo and Gosatomenergonadzor (USSR-era bodies).
- ICS / categories: Pipeline components and pipelines (ICS 23.040), Welding (ICS 25.160), Nuclear power plants / safety (ICS 27.120.20) — relevant classification areas for this document.
- Edition / version: Original 1989 edition (OST 24.125.31-89).
- Number of pages: 8 pages (electronic/PDF versions listed in commercial libraries).
Scope
The standard applies to butt-welded joints of nuclear power plant pipelines made from perlite-class steels (examples cited in the normative entry: grades 15ГС per TU 14-3-460 and 16ГС per GOST 19281) and common carbon steels (grades 20 per GOST 1050 and 20К per GOST 5520). OST 24.125.31-89 specifies joint types and principal dimensions to be used during design and manufacture of NPP piping components; it complements other material and welding normative documents referenced within.
Key topics and requirements
- Standardized types (configurations) of butt-welded joints for NPP piping (including single- and double-sided preparations and typical root/face geometries).
- Main dimensional tables for weld preparations: root gaps, bevel angles, land (root face) dimensions, and recommended tolerances.
- Material scope: applicable steel grades and references to relevant GOST/TU material specifications.
- Compatibility notes and normative references to supporting standards (welding electrodes, fluxes, shielding gases, and material technical conditions).
- Replacement/relationship information: indicates which earlier OST it supersedes or replaces where applicable.
Typical use and users
Primary users are designers and engineers of NPP piping systems, fabricators and weld shops producing nuclear piping components, quality assurance and inspection personnel (NDE, dimensional control), procurement/specification authors, and regulatory reviewers responsible for plant piping design and construction. The standard is used when specifying joint preparations and communicating expected weld geometry between designers and manufacturers.
Related standards
OST 24.125.31-89 is part of a family of OST documents for NPP piping (series OST 24.125.xx-89). Related items include adjacent series documents on elbows, bends and fittings (for example OST 24.125.32-89, OST 24.125.33-89, OST 24.125.38-89 etc.) and the material standards cited within (GOST 1050-88, GOST 19281-89, GOST 5520-79, as well as welding consumables and flux standards referenced in the normative list).
Keywords
OST 24.125.31-89; butt weld; weld joint; pipeline; nuclear power plant; NPP piping; weld preparation; bevel angle; root gap; perlite steels; GOST; ОСТ.
FAQ
Q: What is this standard?
A: OST 24.125.31-89 is an industry standard (ОСТ) issued in 1989 that defines types and principal dimensions of butt-welded joints for pipelines used in nuclear power plants (NPPs).
Q: What does it cover?
A: It covers standard joint configurations and main dimensional parameters (bevels, root faces, gaps, angles and tolerances) for butt welds in NPP piping made from specified carbon and low-alloy steels, and it references relevant material and welding normative documents.
Q: Who typically uses it?
A: Engineers and designers of NPP piping systems, fabricators and welders working to nuclear piping requirements, QA/NDE inspectors, procurement/specification writers, and regulators reviewing piping design and manufacture.
Q: Is it current or superseded?
A: Commercial standards libraries list OST 24.125.31-89 in their collections and some list it as available/active; however, catalogue metadata indicates a formal end-of-validity date of 30 June 2003 in at least one registry entry. Users should verify the current formal status (active, withdrawn, or replaced) with the national standards authority or a licensed normative database before applying it in regulated projects.
Q: Is it part of a series?
A: Yes — OST 24.125.31-89 belongs to the OST 24.125.* series of documents addressing components and fittings for NPP piping; several related OSTs cover elbows, bends, fittings and other pipeline parts within the same 1989 series.
Q: What are the key keywords?
A: Butt weld, weld joint, pipe weld, nuclear piping, weld preparation, bevel angle, root gap, OST, GOST, NPP.