The thermostatic shower valve unit I picked up has 3/4 female input connections, and 1/2 output connectors. Because I was geared up for 15mm right through, including all my tap connectors I picked up two 3/4 male to 15mm compression couplers (like this http://www.screwfix.com/p/male-coupler-15mm-x/82086 )
There weren't any rubber washers in the bottom of the holes on this shower valve (unlike the other valves I've bought for the rest of the house) so I wound 12 turns of PTFE onto one coupler, wound it in, and it's fine. On the other one, i first had 12 turns and water was pouring out (well, dripping out at an exceptional rate).
I re-did it, thinking I'd messed something up and it was better, but dripping. I've put 16 turns on and it's still weeping ever so slightly (in half an hour it didn't make a drip but if I rubbed the bottom of the union it would leave a water mark on my finger). Should I up it to 20 turns?
In terms of basic PTFE technique, am i right in thinking that winding the coupler all the way to the bottom is actually detrimental because it forces the threads to one side of the groove, which might open up a path for water on the other side?
There weren't any rubber washers in the bottom of the holes on this shower valve (unlike the other valves I've bought for the rest of the house) so I wound 12 turns of PTFE onto one coupler, wound it in, and it's fine. On the other one, i first had 12 turns and water was pouring out (well, dripping out at an exceptional rate).
I re-did it, thinking I'd messed something up and it was better, but dripping. I've put 16 turns on and it's still weeping ever so slightly (in half an hour it didn't make a drip but if I rubbed the bottom of the union it would leave a water mark on my finger). Should I up it to 20 turns?
In terms of basic PTFE technique, am i right in thinking that winding the coupler all the way to the bottom is actually detrimental because it forces the threads to one side of the groove, which might open up a path for water on the other side?