Low loss double check valve

[Leighloz]

I've recently gone for a new 30 CDi Worcester Bosch Combi (works great) to replace the previous gravity fed system and am looking at a replacing the currrent electrical shower with a new thermostatically controlled mixer - lots of postings already on that so I won't ask the obvious questions on which model....

The new shower will have a flexible hose on it, so will need double check valves on the supply (15 mm pipes, one hot and one cold).

Are there any low loss double check valves (as in low pressure drop and low flow rate drop) that will minimise the impact on the shower flow?

I found this, but at £40 ea, they've got gold in them! But if they work, then maybe.....

http://www.arrowvalves.co.uk/pdf/ed132datasheet.pdf

Is the solution just to put 22 mm double check valves in as a cheaper alternative? Does that make any difference to flow (be gentle with fluid dynamics!!!!)

Any advice gratefully received. Tell me if I've got the wrong end of the stick!

Thanks,

Leigh.

 

[picasso]

Your combi supplies hot water at mains pressure, you dont need low pressure check valves, the shower you buy should have check valves already fitted.