Hi All,
Can anybody please enlighten me regarding double and single check valves?
Questions:
(1) What is the difference between them, and how should I choose which is appropriate for any given application? (I know that the water regs sometimes specify which to use.)
(2) Every valve I've seen has a screw head on the body or a hex bolt head. What for? I presume maintenance, but how?
(3) Screwfix do cheapy 15mm double-check @ 2.39 (16281) and Pegler d-c @ 6.45 (15139), the latter being BS6282-1 and WRAS approved, the former not. Which would you buy?
Many thanks!
Ben