1)I want to put a drain valve immediately above my stoptap. The pipe is 22mm copper but screwfix don't sell 22mm drainvalves only 15mm. Why is that?
2)Why do baths use 22mm pipes when if you tracee the pipes back they are reduced to 15mm? I have a combination boiler.
3) How serious is siphoning on a single stack system? I'm going to use a compact shower trap for the shower and a shallow bath trap for the bath(both 40mm). My understanding, and if i'm wrong please tell me, is that on a single stack system as water drains away from the stack it can syphon the water left in the traps. How is the best way to avoid this?
thanks in advance
scott
2)Why do baths use 22mm pipes when if you tracee the pipes back they are reduced to 15mm? I have a combination boiler.
3) How serious is siphoning on a single stack system? I'm going to use a compact shower trap for the shower and a shallow bath trap for the bath(both 40mm). My understanding, and if i'm wrong please tell me, is that on a single stack system as water drains away from the stack it can syphon the water left in the traps. How is the best way to avoid this?
thanks in advance
scott