Every test is reported against a defined method and reference standard — and that distinction matters: a product standard says what properties the pipe must have, a method standard says how to measure that property. The laboratory works with the second kind.
Two kinds of standard, routinely confused
Product standard versus test method standard
| Product standard | Such as INSO 14427-2 for water supply or INSO 11223 for gas. It fixes the dimensions, strength and marking the pipe must have. The standard mark licence rests on this — mandatory for water supply, an incentive (voluntary) mark for gas. |
|---|---|
| Test method standard | Such as ISO 1167 for internal pressure or ISO 1133 for MFR. It fixes the apparatus, conditions and calculation by which the property is measured. A test report cites these. |
A usable test report cites the method standard number, not just the name of the test.
The references the laboratory works to
The laboratory's tests cite Iranian national standards (INSO and ISIRI) and their international equivalents in ISO, with one EN reference. In most cases the national standard is a transposition of the ISO one and both numbers appear in the report — INSO 6980-1 and ISO 1133-1 for MFR, for example.
| Product | Test | Applicable range | Method (reference) |
|---|---|---|---|
| Polyolefin pipes and fittings, 16 to 630 mm | Determination of dimensions | OD up to 850 mm, wall up to 100 mm | INSO 2412ISO 3126 |
| Determination of tensile properties | up to 20 kN, at 25, 50 and 100 mm/min | INSO 17140-1INSO 17140-3ISO 6259-1ISO 6259-3 | |
| Determination of resistance to internal pressure | up to 100 bar | ISIRI 12181-1ISIRI 12181-2ISO 1167-1ISO 1167-2 | |
| Determination of longitudinal reversion | — | INSO 17614ISO 2505 | |
| Determination of ring stiffness | up to 900 kgf | INSO 11436ISO 9969 | |
| Determination of melt mass-flow rate (MFR) | — | INSO 6980-1ISO 1133-1 | |
| Determination of oxidation induction time (OIT) | up to 232 °C | INSO 7186-6ISO 11357-6 | |
| Determination of the density of non-cellular plastics (Method A) | ρ ≥ 0.79 g/cm³ | INSO 7090-1 (Method A)ISO 1183-1 | |
| Determination of pendulum impact strength by the Charpy method | up to 15 J | ISIRI 12828-1ISIRI 12828-2ISO 9854-1ISO 9854-2 | |
| Polyethylene (PE) pipes | Determination of carbon black content by calcination and pyrolysis | — | INSO 19990ISO 6964 |
| Assessment of the degree of pigment or carbon black dispersion | — | INSO 20059ISO 18553 | |
| Susceptibility to environmental stress cracking induced by insert-type fittings | — | ISIRI 8988ISO 8796 | |
| Unplasticized poly(vinyl chloride) (PVC-U) pipes | Resistance to external blows by the round-the-clock method | OD up to 250 mm, drop height up to 2 m, at 0 °C | INSO 22996ISO 3127 |
| Vicat softening temperature | — | INSO 6982ISO 2507 | |
| Determination of resistance to dichloromethane (DCMT) | — | ISIRI 10609EN 580 | |
| Determination of ash | — | ISIRI 10237-5 |
Why one test carries two numbers
Where the table shows two or more numbers together, one is usually the national standard and the other its international equivalent, or the method is published in parts. Resistance to internal pressure has two: ISO 1167-1 for the general method and ISO 1167-2 for pipes specifically. Both appear on the report.