Apologies if this has been addressed previously (long time lurker, first time poster!)
I'm currently replacing a shower cubicle with a bath/shower combination, using a thermostatic bath/shower valve and bath filler (from bathstore), all of which use 3/4 BSP fittings. I know it may split opinion, but I'm intending to use plastic pipe and speedfit fittings (perhaps compression behind stud walls), but this is not the direct focus of my query. It seems that for 3/4 BSP fittings, the standard "interface" is 22 mm diameter (i.e. from Google searches, no 15 mm to 3/4 BSP seem to exist).
Currently, the shower (now removed and capped off) is fed by hot and cold 15 mm dia copper pipework. I know there are "22 mm to 15 mm reducers" available from Speedfit (and others), but I would be using these as a 15 mm to 22 mm "increaser" if you see what i mean! I know that physically there should be no issue in using such hardware to join 15 mm Cu pipe to 22 mm plastic pipe, but I was just wondering if there are any issues (pressure/flow drop perhaps?) in taking a 15 mm hot/cold supply and increasing it to 22 mm dia to use for a shower and bath?
Many thanks in advance for any help anyone can offer, and thank you retrospectively for such a useful forum!
I'm currently replacing a shower cubicle with a bath/shower combination, using a thermostatic bath/shower valve and bath filler (from bathstore), all of which use 3/4 BSP fittings. I know it may split opinion, but I'm intending to use plastic pipe and speedfit fittings (perhaps compression behind stud walls), but this is not the direct focus of my query. It seems that for 3/4 BSP fittings, the standard "interface" is 22 mm diameter (i.e. from Google searches, no 15 mm to 3/4 BSP seem to exist).
Currently, the shower (now removed and capped off) is fed by hot and cold 15 mm dia copper pipework. I know there are "22 mm to 15 mm reducers" available from Speedfit (and others), but I would be using these as a 15 mm to 22 mm "increaser" if you see what i mean! I know that physically there should be no issue in using such hardware to join 15 mm Cu pipe to 22 mm plastic pipe, but I was just wondering if there are any issues (pressure/flow drop perhaps?) in taking a 15 mm hot/cold supply and increasing it to 22 mm dia to use for a shower and bath?
Many thanks in advance for any help anyone can offer, and thank you retrospectively for such a useful forum!