Introduction To International Organisation For Standardisation ISO Standards

◆Pipe: Large OD series (ISO4200)

Standard (ISO4200) series 1 adopts ANSI dimensions, but only for DN>1100mm (less commonly used) the dimensions of the "Small OD series" are used.

◆Pipe flanges: Including "American flanges" and "European flanges". (ISO7005-1) It represents the current trend in the application of world flange standards.

Nominal pressure rating:

The first series: PN 1.0, 1.6, 2.0, 5.0, 11.0, 15.0, 26.0, 42.0 8 levels;

The second series: PN 0.25, 0.6, 2.5, 4.0 A total of 4 grades.

The first series is the basic series and the second series is the restricted series.

Of the two series:

PN0.25, PN0.6, PN1.0, PN1.6, PN2.5, and PN4.0 are six grades that belong to the "European flange".

PN2.0, PN5.0, PN11.0 (600Psi), PN15.0, PN26.0 (1500Psi), PN42.0 is "American flange";

The two the structure size and sealing surface sizes can not be interchangeable. ISO application standard system commonly used standards are:

ISO6708 pipe fittings Nominal size definition

ISO7268 pipe fittings Nominal pressure definition

ISO4200 Welded and seamless flat-end steel tubes Dimensions and unit lengths

ISO1127 Stainless steel tubes and pipes Dimensional tolerances and quality per unit length

ISO3183 Steel tubes and pipes for the oil and gas industry

ISO6759 Seamless steel tubes and pipes for heat exchangers

ISO7005-1 Metal pipe flanges

ISO7483 Sealing gaskets for pipe flanges according to ISO7005

ISO 3419 Pipe fittings of non-alloy and alloy steel

ISO5251 Stainless steel butt-weld fittings

ISO7121 flanged steel ball valves

ISO10497 valve test Fire test requirements