How We Perform Pipeline Pressure Testing

 In Articles

Pipeline pressure testing is a statutory requirement before the final commissioning of a line or system after its construction or on a regular basis to maintain operating licences. Our firm has extensive experience in this regard, and we have a proven track record of successfully completed projects.

Outline of The Process

The process that is followed can be broken down into four main phases, as is briefly explained below:

  • Pre-cleaning
  • Filling and stabilisation
  • Pressurisation and strength testing
  • De-pressurisation and de-watering

Pre-cleaning and the filling and stabilisation processes are completed before the actual testing is performed.

Pre-Cleaning as Part of The Preparation Process

The system is flushed with high-velocity water, or it is cleaned by blowing high-velocity air through it. If a pipeline runs over a long distance, we clean it through pigging.

Filling and Stabilisation

We fill the pipeline or system with water and expel the air at high points. If needed, we treat the water with the relevant chemicals according to the specifications of the client.

Pressurising of The Line or System and Conducting a Strength Test

Once the line or system has been cleaned and stabilised, we pressurise it. This is done to the predetermined test pressure. Once this level is reached, we commence with the strength testing.

The test is successful if no leaks, loss of pressure, or deviations in pressure are detected as the result of temperature fluctuations for the entire hold period.

The pressure is maintained in the line or system until a company or third-party representative has witnessed the performance of the system. The documentation that includes temperature and pressure logs, calibration certificates, and chart recordings are signed and submitted to the client company.

De-Pressurising and De-Watering the Pipeline or System

Once the leak test has been accepted, we de-pressurise the line or system in a controlled manner by following the appropriate procedures. A de-watering pig is used to expel the test water at the receiving header to the relevant draining points. The pig is propelled with compressed air from the launching header. The pig approach is followed for de-watering where possible. We dispose of the expelled water according to the specifications from the client.


We perform the test according to the client’s requirements and in compliance with relevant specifications. Once the process is completed, we forward the relevant documentation to the client. Such includes:

  • Logs of the pressure or temperature measurements
  • Chart recordings of the pressure or temperature
  • Logs for pigging
  • Logs for cleaning
  • Hydro test acceptance certificate
  • Cleaning acceptance certificate

The client thus has a complete audit trail of the process followed. We comply with safety procedures and ensure that the work is completed in a timely manner.

In Conclusion

Pipeline pressure testing forms an integral part of preparing for the commissioning of a system, plant, or pipeline. For transmission pipelines, usually, a pipeline is pressure tested every five years depending on the pipeline age condition and RBI (risk based inspection) procedure. It is imperative that the process be completed in a timely manner in accordance with the relevant safety standards and specifications. To this end, clients benefit from our thorough process. Get in touch for more information.

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