Isolation valve bore flow restriction?

[xAlex]

Hello. I have got to fit mono-bloc flexi’s to a 15mm pipe. It seems that a flat faced isolation valve will do the trick:
1) in a review someone voiced a concern that if it was not ‘full bore’ it would restrict water flow. Is this true and if so, is there such a thing as a full- bore flat faced isolation valve?
2) the end of the flexi is female, approx 20mm ID. Does this mean that I need a 1/2” BSP valve?

thank you!

 

[oldbuffer]

1. Valves which are not full bore WILL restrict flow.
2. I'm not aware of any flat faced full bore valves.
3. Use a brass adaptor like Screwfix 2665R.
4. A 1/2" BSP female thread has an internal diameter of 19.1 mm.

 

[terryplumb]

The monoblocs flexible hose tap tails will be more restrictive than an isolation valve that isn't full bore. However ,fitting a tap tail adaptor to the isolation valve will allow you to connect them up.