Is RTRP Pipe the Same as GRP Pipe?

RTRP is more of a generic term used to denote thermosetting plastic that has been reinforced with any material [glass, carbon].

GRP is a more specific term where the resin has been specifically reinforced with glass fibres

However it is not uncommon to refer one for the other

At least in the USA there have been MANY different acronyms used in the past to refer to variously reinforced (and various polymer binders with or without various fillers etc.) composite pipes. However, it appears the most recent version AWWA C950-07 standard for Fiberglass Pressure Pipes appears now wanting to more simplify this, as it now contains an opening statement with only a couple basic acronyms, "Both glass-fiber-reinforced thermosetting-resin pipe (RTRP) and glass-fiber reinforced polymer mortar pipe (RPMP) are fiberglass pipes." and then in a more detailed glossary area it further defines these acronyms, "19. Reinforced polymer–mortar pipe (RPMP): A fiberglass pipe with aggregate. 20. Reinforced thermosetting-resin pipe (RTRP): A fiberglass pipe without aggregate [While it is not be a formal definition, I suspect the ""Mortar" may reflect that a filler like some sort of silica sand has been added to the wall.]

I believe there are also very wide variations in how various pipe styles from various vendors have been constructed/composed. e.g. I think I've seen references that indicate the glass etc. reinforcement may make up anywhere from maybe 30%-80% or so of the composition (with some higher percentages maybe e.g. what they are trying to use for at least structural pressure strength etc. in some oil fields), and then of course there are all the varied angles and plies of said reinforcement (where the pipe basically gets what structural strength/fracture resistance it has).

It is certainly is not like e.g. a ductile iron or at least common mild steel pipe where you can walk up to any pipe with a caliper etc. in the field and know basically what you really have as far as strength!

If they were <...the same technically speaking...> then why does one have a TLA and the other a FLA when they both could be one thing?

RTRP - Definition by AcronymFinder

GRP - Definition by AcronymFinder

The temperature and pressure of the wetting agent, an item often overlooked by those specialised in the mechanical domain, have a fundamental influence on the selection of materials, particularly in corrosion resistance and permissible stress calculations; at the moment, the forum has so little to go on to be able to advise.