🔩 Determination of the resistance of thermoplastics pipes, fittings and piping systems to internal hydrostatic pressure at a given temperature — after conditioning the test pieces are subjected to a constant internal pressure for a specified time or until failure, in water, another liquid or air at a constant temperature; end caps type A (transmitting the end thrust to the test piece) or B (not transmitting it), tank ± 1 °C or oven +2/−1 °C, pressurizing equipment keeping the pressure within +2/−1 %, PN-EN ISO 1167-1

Materials and NDT PN-EN ISO 1167-1

Overview

WHAT THE STANDARD COVERS. We read the text of the standard in the iTeh sample of ISO 1167-1:2006 (English text): from the title page through the contents, foreword, introduction and Clauses 1–4 to 5.4 (pressurizing equipment, beginning of the paragraph on supplying several test pieces) on page 3 inclusive. Outside the sample remain further apparatus (5.5–5.7), test pieces (6), calculation of test pressure (7), checking of the apparatus (8), conditioning (9), procedure (10) and test report (11).

ACCORDING TO THE TEXT OF ISO 1167-1:2006 (foreword, introduction, Clauses 1–5.4). The standard was prepared by ISO/TC 138/SC 5 “General properties of pipes, fittings and valves of plastic materials and their accessories — Test methods and basic specifications”; the first edition of ISO 1167-1 together with ISO 1167-2 cancelled and replaced ISO 1167:1996, and together with ISO 1167-3 — ISO 12092:2000, as their technical revision; the ISO 1167 series has parts: 1 — general method, 2 — preparation of pipe test pieces, 3 — preparation of components, 4 — preparation of assemblies. Introduction: internal pressure tests are the basis for assessing the short- and long-term properties of thermoplastics piping system parts; Part 1 describes the pressurizing equipment, procedure and report, Parts 2–4 — preparation of test pieces for pipes, components and assemblies. Scope (1): general method for determining the resistance to internal hydrostatic pressure at a given temperature of thermoplastics pipes, fittings and piping systems for the transport of fluids; covers water-in-water, water-in-air and water-in-liquid tests. Normative references (2): ISO 1167-2, -3, -4, ISO 3126 (dimensions of plastics components), ISO 9080 (long-term hydrostatic strength by extrapolation). Terms (3): component (fitting or valve supplied as an integral unit); SDR — ratio of the nominal outside diameter dn of a pipe to its nominal wall thickness en. Principle (4): after conditioning the test pieces are subjected to a specified constant internal hydrostatic pressure for a specified time or until failure of a test piece or pieces; throughout the test the environment has a constant temperature — water (“water-in-water”), another liquid (“water-in-liquid”) or air (“water-in-air”); the standard or specification referring to Part 1 shall specify: type of end caps, test temperature, SDR or S series or size of pipe or fitting, number of test pieces, pressure p or hoop stress σ, type of test, duration under pressure and failure criteria, and requirements triggering additional testing. Apparatus (5.1–5.4): end caps allowing the test piece to be sealed, connected to the pressurizing equipment and purged of air before testing — type A: fittings rigidly connected to the test piece but not to each other, transmitting the hydrostatic end thrust to the test piece (e.g. flanged plates on the ends of a large-diameter pipe, optionally fused when of a material compatible with the test piece); type B: metal sockets sealing onto the outer surface of the test piece, connected to one another (e.g. by rods), not transmitting the end thrust to the test piece, with longitudinal clearance to avoid buckling from thermal expansion — with external rods, contact of the test piece with a rod disqualifies the test; sharp edges in contact with the pipe (other than toothed grips) are rounded off; end cap materials that might adversely affect the test piece should be avoided as far as possible; for testing components the end caps are replaced by pressure-tight devices according to ISO 1167-3; type A end caps are used for long-term hydrostatic strength of materials according to ISO 9080; according to the note times to failure can depend on the type of end caps. Tank with water or another liquid at a constant temperature ± 1 °C or an oven kept within +2/−1 °C; with an environment other than water precautions shall be taken (safety, interaction of the liquid with the material of the test piece), and comparative tests are carried out in the same environment; as results are strongly influenced by temperature, the tolerance should be kept as small as possible, e.g. by forced circulation of the fluid; when testing in air the pipe surface temperature should also be checked; potable water should be used and contamination with substances affecting the result, e.g. detergents, lubricants, avoided. Supports or hangers so that test pieces do not touch each other or the walls of the tank or oven. Pressurizing equipment applying pressure gradually and smoothly according to Clause 9 and keeping the indicated or measured pressure within +2/−1 % for the duration of the test; as results are strongly influenced by pressure, the tolerance should be kept as small as possible; pressure should preferably be applied individually to each test piece, and equipment supplying several test pieces simultaneously is permitted under a condition described further (outside the sample).

STATUS (as of 03.10.2026). The PKN search (term “PN-EN ISO 1167-1”, 03.10.2026) shows PN-EN ISO 1167-1:2007 (Polish version, “Introduces: EN ISO 1167-1:2006 [IDT], ISO 1167-1:2006 [IDT]”) without a withdrawal note and PN-EN ISO 1167-1:2006 in the English and German versions, withdrawn and replaced by PN-EN ISO 1167-1:2007. In the iTeh catalogue (read on 03.10.2026) ISO 1167-1:2006 has the status “Published”, stage 90.93 (standard confirmed) since 25.10.2021.

HOW MANY LABORATORIES AND IN WHAT FORM (copy of the accreditation scope database, load up to 17.09.2026, read on 03.10.2026). The number 1167-1 appears in 5 records at 5 laboratories: AB 005, AB 041, AB 163, AB 237, AB 1256. In the current PCA documents (read on 03.10.2026, issues from 26.11.2025 to 20.07.2026) the number appears in 5 rows — one at each; in each of the five documents the number of page markers equals the number of PDF pages, without repetitions; a search of all 1291 PCA documents downloaded from BIP on 03.10.2026 found no laboratories outside the database copy (17 laboratories on the list have no link to a scope document on BIP). The form “PN-EN ISO 1167-1:2007” together with PN-EN ISO 1167-2:2007, PN-EN ISO 1167-3:2008 and PN-EN ISO 1167-4:2008 (AB 005, AB 163, AB 237, AB 1256) and “PN-EN ISO 1167-1” without year (AB 041). None of these items is suspended. The “Laboratories” tab (term “PN-EN ISO 1167-1”) shows all 5 laboratories — checked with a tab query on the production server labcoda.pl on 03.10.2026.

WHAT THE LABORATORIES TEST (items in PCA). Thermoplastics pipes, fittings and assemblies (AB 041, AB 237, AB 1256), at AB 041 also multilayer pipe and fitting systems and PE/metal joints; plastic products with closed sections (AB 005, AB 163). Characteristic: resistance to internal pressure (at constant temperature — AB 163, AB 237). Method: water-in-water (AB 163), water-in-water and water-in-air (AB 041, AB 1256), hydrostatic pressure test (AB 237). Ranges: pressure up to 6 MPa for diameters up to 400 mm and up to 0,5 MPa without diameter limit (AB 005), up to 10 MPa and diameters up to 315 mm (AB 163), up to 100 bar at (20–95) °C and diameters up to 250 mm (AB 1256), diameters up to 630 mm (AB 041), up to 800 mm (AB 237).

WHERE A SEEMINGLY CORRECT RESULT IS EASY TO GET. With end caps: types A and B give different axial loading, and the time to failure can depend on them; for ISO 9080 — type A only (5.1). With type B rods: contact of the test piece with a rod invalidates the test (5.1). With temperature: tank ± 1 °C, oven +2/−1 °C, and in air the pipe surface temperature is also checked (5.2). With pressure: +2/−1 % throughout the test, applied gradually (5.4). With water: potable water without detergents or lubricants (5.2). With comparisons: comparative tests in the same environment (5.2). With parameters: pressure, temperature, time, number of test pieces and failure criteria are given by the product standard, not by ISO 1167-1 (4).

WHAT WE DO NOT GIVE. We did not read the formulae for the test pressure from dimensions, SDR or hoop stress, checking of the apparatus, conditioning, the course of the test or the content of the report (Clauses 6–11). We do not give strength requirements for particular piping systems.

Method principle

A test piece of pipe, fitting or assembly with end caps is filled with water, purged of air and after conditioning subjected to a constant internal hydrostatic pressure kept within +2/−1 %, in water, another liquid or air at constant temperature (tank ± 1 °C, oven +2/−1 °C), for a set time or until failure. Pressure or hoop stress, temperature, time, type of end caps and failure criteria are specified by the product standard referring to ISO 1167-1.

Applications

• Thermoplastics pipes, fittings and piping systems for the transport of fluids (1)
• Long-term hydrostatic strength of materials according to ISO 9080 — with type A end caps (5.1)
• Pipes, fittings, assemblies and closed-section products — resistance to internal pressure in the accreditation scopes of 5 laboratories in PCA

Key parameters

Standard

Standard number

PN-EN ISO 1167-1:2007

Title (PL)

Rury, kształtki i zestawy z termoplastycznych tworzyw sztucznych do przesyłania płynów — Oznaczanie wytrzymałości na ciśnienie wewnętrzne — Część 1: Metoda ogólna

Title (EN)

Thermoplastics pipes, fittings and assemblies for the conveyance of fluids — Determination of the resistance to internal pressure — Part 1: General method

Step-by-step procedure

1. Test parameters

   From the product standard: end caps, temperature, size or SDR, number of test pieces, pressure or stress, type of test, duration, criteria (4). PN-EN ISO 1167-1:2007 without a withdrawal note (03.10.2026).

2. Test pieces

   Preparation according to ISO 1167-2 (pipes), -3 (components) or -4 (assemblies); end caps type A or B (5.1).

3. Environment

   Tank ± 1 °C or oven +2/−1 °C; test pieces on supports without contact (5.2, 5.3).

4. Pressure

   Air purging, gradual application of pressure and holding within +2/−1 % for the test duration (5.1, 5.4).

5. Result

   Time to failure or survival of the set time; calculation and report according to Clauses 7–11 (not read).

Required equipment and apparatus

Reagents, media and consumables

Health and safety (OHS)

• Pipe burst under pressure — guards and exclusion zone
• Hot water in the tank — risk of scalding

Frequently asked questions