Double or Single Check Valves in bathroom?

[Possom]

If a bathroom has:

a) one toilet,
b) one basin (with mixer tap),
c) one bath with mixer bath filler,
d) one hand shower, and,
e) one shower over bath,

how many single check valves and/or double check valves are required? A combi boiler is used in case that makes any difference.

Thanks.

 

[Possom]

Apparently showers can have an internal check valve.

With regards to an internal shower setup, which consists of an overhead shower, a hand shower and a concealed two-way diverter, would any possible internal check valve be within the two-way diverter, the overhead shower, or the hand-held shower?

 

[Hot&Cold]

Possum,you asked this on the screwfix forum and got several replies,dont you believe the screwfix contributors ?

http://community.screwfix.com/threads/double-or-single-check-valves-in-bathroom.190227/

Double or Single Check Valves in bathroom?
Discussion in 'Plumbers' Talk' started by Possom, Today at 1:08 PM.

1. 
   PossomMember
   If a bathroom has:
   
   a) one toilet,
   b) one basin (with mixer tap),
   c) one bath with mixer bath filler,
   d) one hand shower, and,
   e) one shower over bath,
   
   how many single check valves and/or double check valves are required? A combi boiler is used in case that makes any difference.
   
   Thanks.
   
   Possom, Today at 1:08 PM

 

[Possom]

Er, yes. However, I don't know the answer to my last question above.

 

[Hot&Cold]

With regards to an internal shower setup, which consists of an overhead shower, a hand shower and a concealed two-way diverter, would any possible internal check valve be within the two-way diverter, the overhead shower, or the hand-held shower?

Maybe,it will be listed in the installation instructions of the equipment you have purchased.
https://www.diynot.com/diy/threads/concealed-or-wall-mounted-2-way-diverter.484114/#post-3926953