Radiator valve size interchangeability

[samiebon1]

I'm wanting to swap around the sides of my TRV valve and Lockshield, but apart from them both being 15mm connections, are valve bodies generally universal/the same dimensions? I.e. will I have to play around with tail protrusion and inlet pipe dimensions.

The valves are Drayton eB valves and lockshields.

 

[CountryFan]

If they’re the same make, and often if they’re not, you’re usually ok swapping over. It’s when you get cheap Chinese valves where they can change just a fraction.