Why Do Cylinders Need Hydrostatic Testing?

Cylinder hydrostatic testing is something that a wide variety of organisations have to consider. As per Australian Standards 2030.1 -2009 Gas Cylinders – General Requirements, SCUBA cylinders, SCBA cylinders, portable CO2 fire extinguishers, suppression system, ANSUL and air bank cylinders all need to be regularly hydrostatically tested. Hydrostatic testing is generally conducted to ensure both the maximum performance and safety of a wide range of cylinder applications.

But why do cylinders need hydrostatic testing?

That’s a good question! Before we can answer why pressurised cylinders need to undergo hydrostatic testing, let’s break down the basics of hydrostatic testing procedures and what the tests determine. As leaders in the cylinder hydrostatic testing service industry, Newcastle Safety Servicing are more than qualified to provide professional, expert advice on cylinder hydrostatic testing.

What Is the Purpose of a Hydrostatic Test?

Let’s define hydrostatic testing: A hydrostatic test is a process in which pressure vessels (such as cylinders) are tested for strength and leaks. Essentially, hydrostatic testing works by completely filling the cylinder up with water, removing the air in the cylinder, and pressuring the system higher than the cylinder’s design pressure limit.

The purpose of a hydrostatic test is to test the strength of the pressurised vessel. Hydrostatic testing is conducted to expose any leaks, weaknesses, faulty components or damage. If a pressurised pipe, cylinder or vessel passes the hydrostatic test, it passes a national Australian standard under AS2337.1 Gas cylinder test stations Part 1: General requirements, inspection and tests – Gas cylinders and AS2337.3 Gas cylinder test stations Part 3: Transportable gas cylinders – Periodic inspection and testing of composite gas cylinders.

Why Do Cylinders Need Hydrostatic Testing?

Cylinders require hydrostatic testing to ensure they will not fail under pressure during real-world application. In order to make sure that lifesaving equipment is always performing accurately, precisely and can be trusted to do so throughout service life, breathing apparatus, SCUBA, medical and fire extinguishers must be regularly tested. Depending on the application of the pressurised cylinder, it may require annual cylinder hydrostatic testing.

Cylinders that require hydrostatic testing are those that are used in diving, confined spaces, firefighting, mining, the medical field, aviation and emergency rescue. As all of these applications are incredibly hazardous and require emergency support of pressurised cylinders, neglecting to test cylinders can be life-threatening for the user or those in the immediate surrounds.

The importance of cylinder hydrostatic testing cannot be understated. The reason cylinders require hydrostatic testing because if high-pressure cylinders are faulty in the real world, they can explode under pressure and cause serious harm in critical situations. Without accurate hydrostatic testing, users of SCBA, SCUBA, fire extinguishers and pressurised cylinders cannot rely on such systems when they are needed most.

What Does Hydrostatic Testing Determine?

A hydrostatic test will determine whether there are any cylinder leaks, faulty components and how the cylinder performs under extreme pressure. Cylinder hydrostatic testing will also assess pressure tightness and cylinder strength to ensure that the cylinder can perform accurately and meets Australian Standards.

Hydrostatic Pressure Test Procedure

Firstly, the cylinder will undergo an external inspection to look for any physical damage, corrosion, gouges, dents or alterations. Special attention is paid to repainted cylinders as they may have been heat-treated or had gouges or dents filled. All of these aforementioned elements can seriously impact the compressed air cylinder’s integrity, and as a result, lead to failed hydrostatic testing.

The next step of the hydrostatic test procedure is to drain the cylinder before removing the valve. If the cylinder requires servicing and a test, its repairs can also be performed at this time. The neck thread and internal space are inspected for wear, corrosion, pitting or rust using telescopic mirrors. As we all know, steel cylinders can become rusted; some brands will rust more than others due to the amount of carbon used in the steel when manufactured initially. It is worth noting that rust in steel cylinders is typically a result of negligence by its user or fill station.

If a cylinder is filled with moist air from a station that has not adequately maintained its filters or compressor, this may also be another reason for cylinder rust. There may also be oil found if this is the case.

The next step of the hydrostatic pressure test procedure is when the cylinder is hooked up to the testing service panel. When all air is removed, the cylinder is pressurised to its test pressure and held there for one minute. The pressure is slowly released, and the expansion measured on a manometer tube. The maximum allowed increase in pressure is calculated as per the Australian Standards for air cylinders.

The cylinder is disconnected from the test panel and inverted to drain after which warm air on the cylinder heater is used to dry the cylinder. After a final internal inspection to ensure proper drying, the neck “o” ring is replaced, and the valve is installed.

The hydrostatic pressure test procedure’s final step occurs when the cylinder is filled, leak tested at the neck and certified. In most cases, unless additional servicing is required, Newcastle Safety Servicing can have this process complete and the cylinder ready to go within 48 hours.

How Often Do Cylinders Need to Be Hydrostatically Tested?

How often cylinders require hydrostatic testing depends on the application of the pressurised cylinder, the industry in which it is used and how often it is utilised. For example, cylinders used in SCBA (breathing apparatus) equipment require hydrostatic testing every 3-5 years – depending on where the equipment is applied. SCUBA cylinders should be tested every 12 months. Cylinder hydrostatic testing frequency is carried out with Australian Standard 2030.1 by a certified test station – such as Newcastle Safety Servicing’s SAI Global Accredited test station. Following the testing service, cylinders are stamped on the neck area indicating the month, year and testing station number. If a cylinder does not have a current test stamp, it will not and should not be filled and used.

How Can Newcastle Safety Servicing Help?

Newcastle Safety Servicing are one of NSW’s leading providers of cylinder hydrostatic testing services. Working with a wide scope of industrial equipment, Newcastle Safety Servicing offer a certified testing station to provide cylinder hydrostatic testing. Our fully trained and experienced professionals can test all types of pressurised air cylinders – providing peace of mind and assurance that your equipment meets relevant Australian Standards.

Servicing the entire east coast of Australia, Newcastle Safety Servicing provide a wealth of industrial safety services to a diverse portfolio of clients. If you’d like to enquire about our cylinder hydrostatic testing, get in touch with our team today. You can inquire online or contact Newcastle Safety Servicing on (02) 4960 1372 to talk to a testing technician.