What are you trying to do? Is this just to put 3/8" tap flexi's onto 15mm hot and cold feeds? If so the brass 3/8" adapters you have linked to fit into a standard 15mm ISO compression valve, nothing else needed.
Yes.
The new tap hasn't arrived yet, so although a benefit of decent quality German kit (read, expensive!) is that there are good dimensional drawings and instructions available before one buys, it's still good practice to have the thing in my hands and see exactly how/if it will fit, yes?
So:
1. The manufacturer claims the flexi tails are 900mm long.
2. That would, or could, take them under the bottom shelf of the cabinet, into the 6 inch void below.
3. A plus of that is that any leaks/bursts will happen where they will do far less damage. The kitchen has a suspended floor, so most water would end up below the floor.
4. If I do connect it inside the cabinet (under the sink) the pipework actually gets quite a bit more complicated. Or at least messy, as the flexi tails are probably "too long". If I try and keep them inside the cabinet there has to be way more plumbing inside the cupboard under the sink, danger of bashing, lots more notches to cut out of the shelf, etc. etc.
5. So I'm tempted to have everything underneath. This also ties up with a re-arranged dishwasher connection, by the way.
6. But that's a bit awkward when it comes to tightening up compression joints. And anyway, every compression joint is another potential leak. I shy away from them if possible. Sometimes that makes things harder, as I don't have many isolation valves around the house. But that's just me. Sometimes I regret that.
7. So I'm planning (at this stage) to do as much as I can in soldered copper, all of which can be done on the bench away from the job. The other joints would be pushfit Hep2o lever isolation valves, a pair of pushfit Hep2o elbows (to join to existing Hep2o) and the two screw on 3/8 flexi tap connectors themselves. The 3/8 x 15mm adaptors
could go directly into the iso valves, yes. But probably not in a convenient or elegant way. They might end up being in a place with some lateral strain on the compression joint, not good.
But as I say, things will become clearer once the tap arrives.
PS.
NONE of my compression joints has ever leaked, except in the initial stages - you know, gradually nipping it up until it stops. But I still don't like them. Most of mine have been on the CH, but I have some on the supply, which have never leaked, and it's 5 bar mains pressure here. Though thinking about it they are nearly all under the house - maybe I should lift the trap and have a look, for all I know it's a swimming pool under there!
