fitting a new sink

[mrcrow]

my replacement sink came with an accessory pack which contained this
it seems to be an inline non return valve


123 by mrcrow_uk, on Flickr


my supplies are both at mains pressure, hot is via my condensing boiler
is this a necessary fitting, and in which supply should it go

need info fast please...doing the sink tomorrow
cheers
geof

 

[PlumbGas]

If it is a check valve (non return) which it looks like it goes on the hot tap feed, it stops the cold running down the hot supply

 

[mrcrow]

If it is a check valve (non return) which it looks like it goes on the hot tap feed, it stops the cold running down the hot supply

thanks PG
i can fit it with confidence now knowing it will do as intended
cheers
geof