Periodic testing of gas cylinder to TPED, UKAS and DOT accredited standards.

All compressed gas cylinders have to be hydrostatically tested every 10 years to ensure they are safe and fit for purpose. Gielle has in-house test facilities to enable us to carry out cylinder testing. We hydrostatically test and maintain fire suppression cylinders, liferaft cylinders and BA cylinders to both TPED, UKAS and  American DOT standards.Hydrostatic testing involves the cylinder being filled with water and placed inside a water-filled high-pressure chamber. Water pressure inside the cylinder is increased (150% of maximum working pressure) causing the cylinder to expand slightly.

This in turn displaces a small amount of water from within the chamber, which is collected and measured. If the cylinder expansion is within regulation limits (< 5%), then the cylinder has passed and can be certified fit for purpose. Compliant cylinders are dried out, stamped as tested with the current month and year, refilled with the appropriate suppression agent and placed back in service. Failed cylinders must be destroyed.

Our in-house inspection body is accredited by TPED, UKAS and DOT and ensures that all cylinders are tested impartially and to the highest possible standards. Our fully trained inspectors conduct periodic testing of fire suppression cylinders for Facilities Management and Fires suppression engineers all over the world. Our state-of-the-art equipment is routinely calibrated and verified by independent inspection bodies to ensure our own in-house testing is accurate and effective.

Hydrostatic testing FAQ’s

The TPED and DOT accredited standards requires all cylinders to be hydrostatically tested every 3, 5, or 10 years. The time allowed by law is determined by a variety of factors such as the type of material, the gas it contains, its age, and special permits the cylinder may have been manufactured under.

What is a hydrostatic test?
A “hydro test” is an approved way to test the structural integrity of a compressed gas container. It is performed by removing the valve, filling the container with water, and then pressuring the container above its operating limit. The expansion of the cylinder is measured, recorded, and analyzed. If cylinder expands beyond certain limits, the cylinder must be condemned.

How often is a hydro test required?
This depends on the rating of the cylinder and the date it was last tested. The month and year of each hydro test is stamped onto the cylinder between a letter and four numbers identifying the tester.


    +39 080 311 89 98

    Hydrostatic Testing & Tank Inspection

    Hydrostatic testing is the most widespread way to inspect a compressed gas container for leaks or defects. The cylinder undergoes hydrostatic testing with the purpose of checking whether it can safely hold its rated pressure. Hydrostatic testing is critical when it comes to compressed gas containers because they can explode in case if they fail when containing compressed gas.

    A hydrostatic test includes filling the container with a practically incompressible liquid (water) and examining it for leaks or changes in shape. The test pressure is considerably higher than the operating pressure to ensure safety. Usually 150% of the operating pressure is applied. Water is used in hydrostatic testing as it is almost incompressible and will only expand by a very small amount.

    In case of high-pressure gas use, it could exceed its compressed volume, posing a great risk of explosion. All compressed gas containers need regular hydrostatic testing. The frequency of the maintenance depends on the cylinder material.

    The DOT recommends visual inspections to be performed on a regular basis as well. The DOT demands that hydrostatic retesting and re-qualification would be handled by registered specialists who have been certified. Gielle all the necessary qualifications for hydrostatic testing are met, so you can trust our company for examining your compressed gas cylinders.

    The object of the pressure tank testing is to check if there is a significant drop of pressure which usually signals of a crack or hole in the tank. Pressure accumulation is a potentially dangerous situation, that’s why this kind of testingshould be conducted by a plumbing professional.
    Gielle is a specialist in hydrostatic testing and cylinder maintenance. Our customers include the military, major gas manufacturers, independent welding supply companies, fire extinguisher companies, fire departments, and municipalities.

    The Benefits of Hydrostatic Cylinder Services

    Preventing dangerous accidents

    Hydrostatic cylinder testing is designed to catch even small structural problems early, preventing catastrophic accidents and injuries.

    Cost savings

    Instead of replacing older cylinders before testing is due, you can have them recertified and save money.

    Meeting TPED / DOT specifications

    Instead of replacing older cylinders before testing is due, you can have them recertified and save money.

    Avoiding penalties and fines

    Transporting cylinders that are outdated or have not been tested can lead to costly fines and other penalties, jeopardizing your business.

    Providing peace of mind

    When you have cylinders that contain flammable or dangerous materials, regular hydrostatic cylinder testing ensures that they are safe and leak-free.

    Increase efficiency

    By working with a single partner to achieve a seamless solution throughout your project lifecycle.

    Make sure your cylinders are safe and structurally sound

    Bring them to Gielle today for comprehensive hydrostatic cylinder testing.
    Contact our experts at Gielle today to learn more about the benefits of routine hydrostatic cylinder testing.

    Ultrasonic Examination

    Cylindrical structures, including pipes and pressure vessels, must be defect-free to remain dependable and safe. Ultrasonic examination testing uses ultrasound technology to measure flaws, defects, and wall thickness in steel high-pressure compressed gas cylinders. This is an effective way to test a cylinder’s overall safety and structural integrity. Gielle is certified to perform UE testing. For the certified experts to perform UE testing, contact us online today!

    Cylinder Reconditioning

    We recondition high-pressure compressed gas cylinders to conserve resources and save you money. Our techniques allow used fire extinguishers, oxygen tanks, SCUBA gear, and more to remain in use for decades. We remove any labels, shot blast the surface, and apply new paint to make the used cylinder look new. We thoroughly test all reconditioned cylinders to ensure they meet performance standards. In the end, you receive a cylinder that looks and performs like new for a fraction of the cost.

    Cylinder Maintenance

    Our maintenance and reconditioning services include:

    • Cosmetic exterior blasting and painting
    • Internal shot blasting
    • Tumbling
    • Valving
    • Neck ring replacement
    • And more
    • Full Hydrostatic Cylinder Test for Steel and Aluminium Cylinders
    • Visual Cylinder Test
    • Visual Plus Eddy Current Test
    • Internal Cylinder Rumble
    • External Refurbish
    • Cylinder Refills
    Refilling available

    CO2 – Foam – Water Mist – FM200 – Novec 1230

    Additional service: Service Exchange Program

    Our Service Exchange program ensures downtime of systems is eliminated maintaining constant asset protection.

    From our comprehensive range of gaseous fire suppression systems we can supply cylinders fully refurbished, tested and refilled to our clients specification. We fill cylinders with HFC227ea, HFC125, HFC236fa, FK-5-1-12, IG541, IG55, N2, CO2, Ar up to 300Bar working pressure.

    Gielle hold one of the largest cylinder stocks in the europe including Hygood, Kidde, Fike, Chubb, Tyco, Siemens and many others. We understand that all fire suppression systems are protecting high value assets and owners cannot afford to be without protection. Our service exchange programme is our solution by eliminating system downtime and therefore saving time and money.

    Emergency refills for discharged systems
    When a fire suppression system is activated and the system has fully or partially discharged, down-time must be kept to a minimum. Where a service exchange is not possible, Gielle can collect discharged cylinders from sites across the Europe using their own fleet of dedicated vehicles. Cylinders can be refilled from certified bulk reserves of F-Gas and ODS held at Headquarters and then returned to site for re-installation and commission. Gielle hold a multitude of filling adapters to suit most types of valve and their custom-built in-house filling rigs are optimized for the rapid refilling of critical asset-protecting service cylinders.

    Collection, Reclamation & Disposal
    Gielle is a name synonymous with the recovery of redundant hazardous fire safety cylinders. Safe hazardous cylinder recovery (technical Waste) is a specialist service provided throughout the UK and our customer services team are on-hand to arrange the whole process including the logistics of safe collection, transport and disposal.

    From our licenced hazardous waste site, we provide a unique cradle to the grave service throughout the world for the recovery and reclamation/disposal of hazardous cylinders and related waste streams.

    We are a dedicated company with knowledge and expertise in providing internationwide service and turnkey solutions

    Ask for an immediate price quote – Call us at +39 080.3118998

    With more than 400 employees throughout world, Gielle has the talent and expertise to provide you
    with the best total fire protection solutions.