Part 1 float valve to refill loft tank? thinking of rebelling again

[ATTQ]

I've got a regular noisy part 2 float valve filling the attic cold water storage tank. The tank is just above a bedroom of course and quite noisy due to pressure and water dropping when filling.

So I was looking at part 1 float valves and can't figure out whats wrong with them. This one looks to have a 15mm compression fitting.

how about a reverse U bend of pipe going up above the level of the edge of the tank, then down at an angle to almost the level of the water...? no noise. The hissing at the valve gap should be lessened by the pipe being full of water until the top of the U, then the fall being at an angle means less of a drop for the water leaving the pipe.

less back fill risk than current set up where plastic outlet of part 2 is anyway lower than top edge of tank if it failed and the overflow was blocked,

open to suggestions though!

 

[ATTQ]

hmmm boringly might not be a compression fitting on the end maybe just a cap. If the arm works a rubber washer onto a seat than water must just be dropping out the bottom before the arm as the rest seem to. do any have a way to attach a pipe to the bottom outlet or are they just plain holes? Shame as it seemed like a good plan

So is a part 2 mainly different in having the outlet on the top? Are they more reliable? quieter/louder? The part 2 one i have i can see the water is very restricted so make a lot of noise. Otherwise thinking I need some pressure reduction valve leading up to it