Alan's right on the Technical Check Sheet it dose say.

Pneumatic System
(Where fitted)
Must meet requirements of the build rules including pressure
relief devices and an easily accessible dump valve that are
away from weapons, drive or sharp edges.

Pneumatic System (Where fitted) Must meet requirements of the build rules!

So it's up to the Roboteer to make sure all paperwork including certificates are up to date!!!

I think most manufacturers can supply certificates of conformity for their unaltered parts if this is any help.

I don't know about independent pressure test certificates but there must be companies that do it.

My problem with this, is it is a little impractical, as this is a combat situation as soon as the robot has been in one fight the certificate could be argued to be worthless.

I don't know how to get round this point. You either run the paper trail to no practical advantage or change the rules.