HYDROSTATIC TESTING

Why do we need hyperbaric testing?Hydrostatic testing at Tyne Pressure Testing

Hydrostatic testing, up to 29,000 psi/2,000 bar, is completed at our site in accordance with international standards such as as defence standard 02-517, BSEN 13480, ASME B31.3,  API 6D, API 17D, API 6D, API 6DSS and ANSI Class.

Hydrostatic testing is a common method employed for testing subsea and topside products within the oil and gas industry and regularly carried out as part of wider factory acceptance testing (FAT).

Hydrostatic testing

Hydrostatic testing is essential to ensure the safety of a component and verify its strength and stability when operating under pressure. This type of testing not only identifies leaks and manufacturing flaws, but can also be used to validate proof pressure and confirm maximum pressure before catastrophic failure.

A hydrostatic test is most commonly used to assess the strength of pressure vessels such as gas cylinders, boilers, fuel tanks and pipelines. The vessel or pipe system is filled with liquid, usually water because of its incompressibility, and pressurised to a specific test pressure for a predetermined period of time.

Pressure tightness is tested by closing the supply valve during the test and measuring pressure loss through calibrated transducers. The component is visually and physically inspected post-test for damage. Specific measurements and quality checks are also carried out at this stage. Depending on how complex the test sequence is, a re-verification proof-pressure test may be carried out.

The pressure applied in hydrostatic testing should always be higher than the operating pressure. The safety margin is typically 150% of the operating pressure, though this is determined by the relevant testing regulation which varies depending on the specification.

Sectors requiring hydrostatic testing:

  • Oil and gas – valves, actuators, pods, cables, electrical connectors, pipe samples, pigging equipment, pressure vessels, flanges
  • Defence – manifold assemblies
  • Nuclear – pipe spools for reactors
  • Energy – heat exchangers

Click here to find out more about our pressure testing chambers.

FAQs

How is hydrostatic testing done?

Hydrostatic testing is performed by filling a component with water and pressurising it to test its integrity. Appropriate connections are required to connect the pressure inlet of the product to the on-site instrumentation comprising pumps, regulators, accumulators, valves and pipework. This system is then used to increase the water pressure until the desired specification is reached. Calibrated pressure transducers are used to monitor the internal pressure as it rises. The pressure is taken up and held. If the pressure drops, this indicates that there is a leakage.

If there is a requirement to monitor visible leakage, submerged gas testing can be used as an alternative to hydrostatic testing as leak paths are identified through the presence of bubbles. Submerged gas testing can also be performed at Tyne Pressure Testing.

Is hydrostatic testing destructive?

This method of testing is generally known as non-destructive testing and it is very rare that the product is destroyed, but it can happen.

Hydrostatic testing is used to prove that a product is fit for purpose and that it can retain its working pressure without any leaks. Therefore the worst case is generally that we will see a leak path, rather than the product being completely destroyed.

How much does hydrostatic testing cost?

Hydrostatic testing costs can vary depending on the size of the component and how comprehensive the test schedule is. The price is usually calculated based on an hourly rate and a lump sum quotation can be provided during the product development stage to help with budget forecasts.

We recommend that you contact us early in the project for a quotation.

How often should hydrostatic testing be done?

Hydrostatic testing is mostly used to test that a prototype or new design tweak is functional and leak free. It is also common for this testing to be carried out on a production batch sample test or if the standard dictates every production unit. Testing can be carried out on existing components in the field and this is dictated by the maintenance schedule of an application normally by the end user.

VIEW CASE STUDY: DEEPSEA VALVE QUALIFICATION TESTING

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