New supply pipe connection, how much space to leave between stop tap and prv / drain cock

[!lsx!]

Hi

I'm part re-plumbing my house having had an ancient cast iron supply pipe replaced with MDPE recently.

My question is after the main stoptap, how much space do you need to leave between it and items such as the prv, drain cock etc.

The instructions for the prv (a Reliance 312) say to leave at least 5 x the pipe diameter before using any elbows in the pipework following it, but is there such a thing as a standard or recommended gap between say the stop tap and double check valve, check valve and prv etc?

 

[denso13]

but is there such a thing as a standard or recommended gap between say the stop tap and double check valve, check valve and prv etc?

No, just as close as reasonably practical.