Need some help on information.
Just realized that this board does not have a category for exterior Commercial Water service lines.
Was faced with testing an underground water service today of eight inch diamter and 450 feet long. E. J. Precott, a water specialist supplier of pipes and testing for this sort of thing was on site, and the water pressure failed.
Since this was a line being tied in to about 65’ of existing line to a College Building, the final hook-up was made this morning. The previous section of new line was tested by EJP at 5 lbs. air pressure.
The last time I personnally installed a water line of that magnitude, I had been advised to pre-test with air at 50 lbs. which would equal the hydrostic pressure of 200lbs for half an hour.
My question’ What is the equation back up for air pressure over hydrostatic pressure.
I can not find the back up for this equation. I have previously been told that whatever hydrostatic pressure used, air pressure would be divided by four to attain the same result with air.
I figured some of you wise Plumbers out there would know this.
Thanks in advance.