What are the plastic rings on the top of a gas cylinder?
A question we are often asked, these are called Cylinder Test Rings. They tell the gas company when a cylinder is next due to be taken out of service for hydraulic testing and internal inspection.
Gas cylinders contain large amounts of stored energy, with some holding pressures up to 300 bar or 4350 psi. It is a legal requirement that they are manufactured to the correct standards and are then periodically inspected and tested to ensure the safety of everyone who transports, fills or uses them.
All gas cylinders used to transport gases by road in the UK are covered by statutory legislation. Specifically, this is The Carriage of Dangerous Goods and Use of Transportable Pressure Equipment Regulations, which implements the Agreement concerning the International Transport of Dangerous Goods by Road (ADR).
ADR requires that gas cylinders are inspected and tested on a periodic basis.
Types of inspection
Gas cylinders are inspected at several points during their life:
- An initial inspection and test at the time of manufacture.
- A routine inspection each time the cylinder is filled.
- A periodic inspection and test at set intervals, or sooner if a routine inspection identifies a concern.
These inspections provide assurance that each cylinder remains fit for purpose and safe for continued use.
What cylinder test rings show
The use of gas cylinder test rings is not mandatory, but they provide a helpful visual indication of when a cylinder is next due for periodic inspection and testing.
The rings are usually fitted during the inspection and test process. A test ring consists of one or more plastic tabs located between the cylinder and the valve.
Rings are colour coded and shaped so that they clearly indicate the year when the next inspection and test is due. Some rings also show the month of the next test.
The sequence of colours and shapes repeats on an 18 year cycle. This means, for example, that the colour and shape used for cylinders due in 2031 will be the same as those used in 2013.
If you would like some further advice, please contact our team of safety professionals who will be able to discuss your gas operations and offer advice as to how our extensive range of gas safety training packages can assist you.
