New LPG installation with 2x 19kg cylinders outside, plus change-over regulator with isolator valve on output, then 10 metres of 15mm copper pipe (3 soldered joints only) running into house to the kitchen, to gas hob (with another isolator just prior to hob).
System Failing tightness test. Dropping approx 0.2 mBar per minute. Hence drops 1 mBar over 4-5 minutes.
No leaks seen anywhere with leak detection fluid. No smell. New install so want to see "no perceptible drop"
During efforts to isolate the fault section and narrow down where it might be, the copper pipe that heads into the house was disconnected just after the regulator and before it goes into the house. This short section still fails TT!! So now we are TT on just a 200mm stub of 15mm copper pipe coming out of the bottom of the change-over regulator and its butterfly isolator valve on its output. See photo and white ringed area. This butterfly isolator also has the test access point. Isolator valve is closed during test. No leaks on the threaded joints.
Swapped digital tester for another and also tried with a mano….. see same dropping with these 2 other testers. Used another new rubber hose to tester too.
So…Swapped the isolator valve…… see same dropping.
remade the joint to copper stub… still drops.
Tried extensive spraying with leak detector all over this tiny area. No leak visible.
Any leak must surely be escaping either.. from the copper stub (nothing visible after extensive spray testing) and remaking the joint and the cap, to be 110% sure…. Or from the test access point on the side of the isolator valve , or the rubber tube to tester (have swapped it for new tube)….. or at some other point on the isolator valve itself, eg leaking up the shaft (nothing seen w spray on the shaft. It cannot surely be leaking back upstream because pressure is higher upstream of the isolator valve..and we can prove this by opening the butterfly on the isolation valve and test device sees pressure rise as expected. Plus we have swapped the isolator valve for new replacement twice now.
Starting to think that there is actually no leak…. Just something weird happening. Being heavier than air..Sinking?..into the stub.. Mixing with air, not fully purge?
can anyone explain this weird dropping. Its a tiny test volume so not ideal. There seems no visible contamination or flux etc, that might be generating a chemical reaction, inside the copper pipe section.
i have attached photo. The area ringed with the white mark around is the only section under test… eg half of an isolator valve and a short copper stub!
any ideas?
System Failing tightness test. Dropping approx 0.2 mBar per minute. Hence drops 1 mBar over 4-5 minutes.
No leaks seen anywhere with leak detection fluid. No smell. New install so want to see "no perceptible drop"
During efforts to isolate the fault section and narrow down where it might be, the copper pipe that heads into the house was disconnected just after the regulator and before it goes into the house. This short section still fails TT!! So now we are TT on just a 200mm stub of 15mm copper pipe coming out of the bottom of the change-over regulator and its butterfly isolator valve on its output. See photo and white ringed area. This butterfly isolator also has the test access point. Isolator valve is closed during test. No leaks on the threaded joints.
Swapped digital tester for another and also tried with a mano….. see same dropping with these 2 other testers. Used another new rubber hose to tester too.
So…Swapped the isolator valve…… see same dropping.
remade the joint to copper stub… still drops.
Tried extensive spraying with leak detector all over this tiny area. No leak visible.
Any leak must surely be escaping either.. from the copper stub (nothing visible after extensive spray testing) and remaking the joint and the cap, to be 110% sure…. Or from the test access point on the side of the isolator valve , or the rubber tube to tester (have swapped it for new tube)….. or at some other point on the isolator valve itself, eg leaking up the shaft (nothing seen w spray on the shaft. It cannot surely be leaking back upstream because pressure is higher upstream of the isolator valve..and we can prove this by opening the butterfly on the isolation valve and test device sees pressure rise as expected. Plus we have swapped the isolator valve for new replacement twice now.
Starting to think that there is actually no leak…. Just something weird happening. Being heavier than air..Sinking?..into the stub.. Mixing with air, not fully purge?
can anyone explain this weird dropping. Its a tiny test volume so not ideal. There seems no visible contamination or flux etc, that might be generating a chemical reaction, inside the copper pipe section.
i have attached photo. The area ringed with the white mark around is the only section under test… eg half of an isolator valve and a short copper stub!
any ideas?