I did 8 yrs in the navy, addmitedly it was on aircraft but it was a great time. As an officer you will be expected to manage alot of people but ultimately major engineering decisions may lie with you. If you do it you will make life long friends and see things that civvy's just don't...
There is an internationally used system, KKS, for process/ power plant identification, this is mostly for pieces of equipment but there may be some info reg pipelines.
There is also ISO 1219 which may offer some more references. Just google it, it may help.