I am not certain that you are asking the right question but, since I do not have any of the class of equipment you name, I am uncertain. What is the substance inside these bottles (e.g. air, hydraulic fluid)? What is the internal volume? What is the maximum pressure? Are they supplied new to you, or did you fabricate them yourself? Are they, in fact, new? or are they old (how old?) What has been done before? Jane

The reason I ask all the questions is that the danger from a pressure vessel failure is a combination of the volume, the pressure (and hence the stored energy) and what is in it. Above certain thresholds, there is a requirement for there to be a written scheme of examination which will define how often the items should be inspected, and how often a full pressure test needs to be done. Your insurer will have a view of competence in testing. Again, when pressure testing, the danger will depend on the stored energy. There is an HSE booklet, 'Safety in Pressure Testing', Series Code GS4 ISBN 9780717616299, which is well worth reading. If a vessel fails under test, parts of it could be ejected as missiles, which is an important consideration. Googling 'pressure testing training' came up with some promising leads. Jane

Thanks Jane and Paul for your replies. Paul I have pm you regarding names as suggested. Thanks again. Rob

Hello Ron Although a hydraulic test is not mandatory, it is nevertheless part of our 'written examination scheme' that has been in place for many years and generally served us well. This was compiled between our service engineer along with our insurance company. The system used has been followed down the years and has never given any cause for concern. However I would like to ensure our procedures are still relevant and that necessary up-to-date training is provided. I take your suggestion on board though that other forms of NDT may suffice and be more practical and will speak to our insurance company for their views. Regards. Rob.