P
Plouasne
I watched the tapping of a water main the other day, the village was renewing its water mains, after 50 odd years
The new water main was 100mm PVC with rubber ring joints, the whole of main was laid, backfilled apart from where the tappings were going to be charged with water
The actual tapping was a bronze skeleton saddle, clamped around the PVC main, one half of the saddle had a screwed boss, with a full way ball valve screwed into the boss, under this was a rubber pad with a hole cut out of it in the centre, this was clamped between the main and the tapping boss to ensure watertightness
All OK so far understand what I have written ??
Now the best bit how the main was actually tapped, nothing so fancy as the British under-pressure tapping machine, no these bu**ers were so laid back they were flat, the tapping machine comprised of a selection of iron tubes that fitted the aperture of the valve, a 13kg Propane cylinder, a gas lamp the a felt roofer would be proud of, and a jump bar
To tap the main the jump bar was placed about a metre away from the valve but in line of it, the selected iron tube was heated until half of it was red hot, this was then inserted into the valve on the collar boss, pressure was brought to bear on the tube with the jump bar until the tube had "burnt" a hole in the watermain the now cold iron tube was withdrawn, water allowed to flow for a bit then the valve was shut, only time I saw a kock up was when they tried to do this for a 2" tapping on a 150mm main, and escaping water quenched the hot tube before it had burnt through the main, then it was Panic and water every where
I would like to say that there is a proper under pressure tapping tool that screws onto the valve, similar to a UK under pressure tapping machine, but that costs money
The new water main was 100mm PVC with rubber ring joints, the whole of main was laid, backfilled apart from where the tappings were going to be charged with water
The actual tapping was a bronze skeleton saddle, clamped around the PVC main, one half of the saddle had a screwed boss, with a full way ball valve screwed into the boss, under this was a rubber pad with a hole cut out of it in the centre, this was clamped between the main and the tapping boss to ensure watertightness
All OK so far understand what I have written ??
Now the best bit how the main was actually tapped, nothing so fancy as the British under-pressure tapping machine, no these bu**ers were so laid back they were flat, the tapping machine comprised of a selection of iron tubes that fitted the aperture of the valve, a 13kg Propane cylinder, a gas lamp the a felt roofer would be proud of, and a jump bar
To tap the main the jump bar was placed about a metre away from the valve but in line of it, the selected iron tube was heated until half of it was red hot, this was then inserted into the valve on the collar boss, pressure was brought to bear on the tube with the jump bar until the tube had "burnt" a hole in the watermain the now cold iron tube was withdrawn, water allowed to flow for a bit then the valve was shut, only time I saw a kock up was when they tried to do this for a 2" tapping on a 150mm main, and escaping water quenched the hot tube before it had burnt through the main, then it was Panic and water every where
I would like to say that there is a proper under pressure tapping tool that screws onto the valve, similar to a UK under pressure tapping machine, but that costs money
