References: AS2885.0 Cl 1.5.48 Defined Term AS2885.1 Section 5.9 Pipeline Assemblies
Pipeline Assembly is a defined term referring to an assembly of pipe and components with simple functionality, such as a scraper or mainline valve; typically (but not always) the piping design is to AS2885 rather than a station piping code.
Is an MLV a “station”? (ref Part 0 diagram)
(Peter Tuft) In common usage the term "MLV" ("mainline valve") can mean three different things, and they are very often conflated:
1. The actual valve (just the valve by itself),
2. The piping assembly that contains the valve,
3. The station that contains the piping assembly plus other infrastructure.
So the answer to the question is that Meaning 1 is not a station, Meaning 2 is not a station, but Meaning 3 is a station. It is good practice to be clear in distinguishing these meanings, particularly to refer to "mainline valve assembly" or "mainline valve station" as appropriate.