LPG servicing

[BIG DUNC]

I have recently bought a range rover which runs on LPG. Since then I have been told the LPG system "MUST" be serviced annualy, and ( by someone else ) that an annual LPG service is not really required if the system is working properly.

So which is it, and what is involved in the annual service?

Is it a close visual inspection of all the components that easily accessable, and a function test?
Does it involve any adjustments, filter changes, leak tests, or pressure tests?

As the "tank" is a pressure vessel, I would expect it to require a hydrostatic test every ten years. In this case, it is a lot younger than that so won't be an issue for quite a while. However, out of interest, does that involve removing the tank from the car and sending it away, or can it be carried out "in situ"?

Any helpful positive replies would be appreciated.

[BIG DUNC]

And slightly off topic, will a 15 year old LPG Range Rover be congestion charge exempt?

[BIG DUNC]

Thanks.
It runs very smoothly, and I would change the parts you mention before taking it to a specialist anyway.

[BIG DUNC]

Out of warranty.
It will only do a very low milage, which is part of the reason I begrudge an "annual" service. If it was "X,000" miles, that would be better.
Also, what is involved with this service? Not even my local LPG specialist could give a good answer ( other than "we give it a good check over" ).