Do O-Rings really need to get changed?

[Guest paulsyk]

Hi

Our service engineer from [omitted] turns up every year to service our extinguishers and whilst his price list states £5 per extinguisher the actual price is much higher by the time he has added the costs for some o rings, washers and other 'things'. Does he really need to change these items? Must be pretty poor quality if it needs replacing every year!!! Or is he just making extra money?

Paul

[Tom Sutton]

It is like any other service engineer car, domestic appliances and others its the only way they can cost the job, until they know what replacement parts are needed.

Put some of the parts down to manufacturers servicing instructions, if the maker says they should be changed annually and the engineer fails to do so, however unlikely, this could raise liability issues. Most refresher courses stress servicing must be carried out to manufacturers instructions.

For example Chubb and Gloria require frangible safety pins to be replaced on every service, other parts may need to be replaced due to wear and tear.

[Safelincs]

However, like with a car service, you need to be careful not to be taken advantage of. Too many service companies (and garages) promise a low service charge and then rip you off on O-rings, washers and pins (or break fluid, new break pads...).

It is actually quite easy to work with a fixed service charge (we do). Yes, there are fluctuations in the real cost to the service company, but most of the items are very low cost.

Harry

[Tom Sutton]

I agree Harry it is caveat emptor but I do understand why some competent service engineers do use the turnout fee, service fee and replacement items method to indicate their cost because if they go for a fixed price the less reputable engineers will undercut them. If employers examined the contracts more fully then they may find what appears to be a good price, is not so, because if they had employed more competent engineers there could be savings such as them identifying over provision for instance.

[Guest david brealey]

Hi There

I have worked in the o'ring industry for 30 years and my response to your question would be yes as the o'rings are in a static application and will have taken compression set, so when serviced the o'ring will not retiurn to its correct size and will loose it's ability to seal, the normal o'rings used in these applications are nitrile which are prone to degrade from ozone light, there are other o'ring compounds which I would recommend, but would still advise replacing every year for safety reasons, for the best quality o'rings there should always be batch numbers and cure dates documented with the o'ring giving full tracability in the event of failure

Kind regards

David

[Guest Prasad]

Dear David Sir,

I am working in the fire extinguisher manufacturing industry. We are having pressure drop problem and this is because the leakage of gas from the sealings. Therefore we require to change the o ring material. We are using nitrile rubber. Could you suggest any other rubber for this application?

Regards,

Prasad