GOST 3262-75 Water-Supply and Gas-Supply Welded Steel Pipes

GOST 3262-75 water-supply and gas-supply welded steel pipes are electric-welded carbon steel tubes supplied in black or galvanized condition for water lines, gas lines, heating systems, and associated pipeline parts. This standard covers threaded and non-threaded pipe, with normal supply length of 4–12 m, dimensional series from DN 6 to DN 150, hydrostatic test capability of 2.4 MPa for light/ordinary series and 3.1 MPa for reinforced series, plus 4.9 MPa when specifically required by the purchaser. Galvanized pipes under this standard require a continuous zinc coating not less than 30 μm.

Specifications

The dimensional range, tolerance limits, straightness, threading, and pressure figures above are taken from the GOST 3262-75 specification text.

Main Features

1. Defined pressure capability by pipe series
   Light and ordinary pipes must withstand 2.4 MPa, while reinforced pipes must withstand 3.1 MPa; a 4.9 MPa test level can also be required by agreement. This is one of the key distinctions professional buyers check when selecting for heating loops, municipal branch lines, and low-pressure gas service.
2. Thread-ready piping standard
   GOST 3262-75 is specifically intended for welding or threading service, with short or long thread options and thread requirements linked to GOST 6357, class B. This makes it practical for maintenance-driven piping systems where cut-thread assembly is still preferred.
3. Galvanized version for corrosion-sensitive service
   The galvanized option requires a continuous zinc layer of at least 30 μm, with coating integrity requirements that reject blistering and peeling. That is especially relevant for exposed water-distribution, utility rooms, and humid-service indoor piping.
4. Broad utility size coverage
   The standard dimensional table spans DN 6 to DN 150 with ODs from 10.2 mm to 165.0 mm, allowing the same standard family to cover small branch lines through larger building-service headers.
5. Controlled straightness and dimensional precision
   Straightness is limited to 2.0 mm/m for DN ≤ 20 and 1.5 mm/m for DN > 20, while increased-precision manufacture tightens OD and wall-thickness control for fabrication use.

Our Advantages

1. Clear coating reliability instead of vague “galvanized” claims
A frequent buyer concern is whether the zinc layer is only nominal or actually controlled. For GOST 3262-75 pipe, the coating requirement is not generic: the galvanized surface must be continuous and the zinc thickness must be not less than 30 μm. That gives a measurable inspection basis for RFQs and incoming QC.

2. Pressure assurance can be matched to project class
Another common technical question is whether the pipe is suitable only for low-duty water service or for more demanding installation classes. GOST 3262-75 already separates light, ordinary, and reinforced series, with explicit test pressures, and it even allows 4.9 MPa when specified. This helps buyers avoid overpaying for unnecessary wall thickness while still keeping a documented pressure margin.

3. Weld integrity and inspection options are already built into procurement language
Professional purchasers often ask whether hydro test alone is enough or whether weld NDT can be required. Under GOST 3262-75, every pipe is subjected to hydraulic pressure testing, and where 100% non-destructive weld inspection is carried out, hydro testing may be omitted while pressure capability is still guaranteed. That creates a practical basis for project-specific QA agreements.

Execution Standards

Application Field

Building heating riser pipe
A typical specific application is threaded galvanized steel pipe for building heating risers, where moderate pressure, threading compatibility, and basic corrosion resistance are all required under one practical piping standard.

Chemical Composition

Mechanical Properties