ISO 13 968 hydrostatic testing for plastic pipes: specifications and use

Main specifications and applications of ISO 13 968 for testing plastic pipes

Overview of ISO 13 968

ISO 13 968 is an international standard that specifies the requirements and methods for hydrostatic pressure testing of thermoplastics pipes and fittings. This standard provides guidelines on determining the resistance of plastic pipe materials or assemblies to internal pressure under specified temperatures and test durations. The main objective is to assess the long-term strength and performance of plastic pipes, which are commonly used in water supply, gas distribution, and other pressure applications. The procedures detailed by ISO 13 968 help manufacturers, laboratories, and regulatory bodies ensure products conform to safety and quality benchmarks for both raw materials and finished pipes.

Specifies test conditions, duration, and minimum requirements for hydrostatic testing
Covers a wide range of thermoplastic materials, including polyethylene (PE), polypropylene (PP), and polyvinyl chloride (PVC)
Applicable both for testing raw material compounds and finished pipes or fittings

Testing parameters and reporting

The standard sets out the procedures for preparing test specimens, filling them with liquid, applying internal hydraulic pressure, and maintaining specific temperature conditions for a defined period. Essential factors such as the dimensions of the pipe, test fluid properties, pressure level, and duration are outlined to ensure test repeatability and reliability. Results must be reported according to the criteria in ISO 13 968, including any pipe failure, deformation, or leakage during the test, complete with data about pipe dimensions, material types, and testing conditions.

Typical industry applications

This standard is widely used in quality control and certification processes in the plastics pipe industry. Both manufacturers and independent laboratories follow ISO 13 968 to evaluate new pipe designs, test material batches, or verify compliance for certification purposes. The scope covers pipes and fittings in water, gas, and industrial piping systems where sustained pressure performance is required.

Takeaway

ISO 13 968 is an essential reference for hydrostatic pressure testing of thermoplastic pipes, supporting safe and reliable operation in pressure applications. It provides industry-accepted procedures for ensuring material and pipe integrity, helping users compare products and maintain consistent quality.

Defines test methods for long-term pressure strength
Applies to a variety of thermoplastic pipe materials
Supports quality control and product certification
Widely adopted by manufacturers and testing laboratories

A stepwise procedure for performing ISO 13 968 hydrostatic testing

Preparation and selection of samples

Begin the process by selecting representative pipe or fitting samples according to the specifications outlined in ISO 13 968. Ensure all samples are clean, cut to the required length, and inspected for visual defects. The environmental conditions, including temperature, should be stabilized prior to the test as specified by the standard in relation to the particular material and intended service application.

Test assembly and filling

Set up the test equipment, ensuring each specimen is securely connected to prevent leaks during the test. Fill the assembly with the specified test fluid—commonly water or another incompressible liquid—ensuring all air is expelled. Confirm the temperature of both the environment and test liquid matches the test requirements.

Install end closures and ensure all joints are leak-tight
Vent any trapped air before pressurizing the system
Record initial conditions including pipe dimensions and fluid temperature

Application of pressure and monitoring

Gradually apply the prescribed internal hydrostatic pressure to the test sample, as specified for the material and size of the pipe or fitting. Maintain this pressure for the test duration, continuously monitoring for any signs of leakage, rupture, or deformation. The exact test duration and pressure levels depend on material type and intended service class, as outlined in the standard.

Evaluation and reporting of results

At the end of the specified test period or upon sample failure, relieve the pressure and carefully inspect the specimen. Record any failures, visible changes, dimensional alterations, or leaks. Prepare a detailed report that includes all relevant test conditions, sample identifiers, and outcomes, following the specification in ISO 13 968.

Document all failures or anomalies during the test
Note testing parameters and environmental conditions
Include diagrams or photographs if required
Ensure traceability to individual samples and batch numbers
Summarize findings for each specimen tested

Quality assurance and compliance checks

The final step involves reviewing test reports for completeness and conformity with ISO 13 968 requirements. If necessary, perform repeat tests or comparative assessments as part of batch release or material qualification. Regular adherence to the procedures outlined in the standard supports consistent quality control and facilitates certification or regulatory submissions.

Summary

Adhering to ISO 13 968 involves careful preparation, precise test execution, and thorough reporting of results. Following each step ensures that data generated is valid, repeatable, and meets industry expectations for the performance of thermoplastic pipes and fittings under pressure.