Page 204 - Pipeline Rules of Thumb Handbook

Corrosion/Coatings 191

Reprinted courtesy of National Association of Pipe Coating Applicators.

Minimum Test Voltages for Various Coating Thicknesses

Coating Thicknesses
32nd Inch Mils Test Volts

— 16 5,000
1 31 7,000
2 62 9,800
3 94 12,100
4 125 14,000
5 156 15,000
6 188 17,100
16 500 28,000
20 625 31,000
24 750 35,000

Reprinted courtesy of National Association of Pipe Coating Applicators.

How much primer for a mile of pipe?

1
3
1
3
3
/
Multiply pipe O.D. by 2 /4 to get gallons of primer per Pipe 4 2 in. in diameter will take 4 /2 ¥ 2 /4 or 12 /8 gallons
mile. of primer per mile (12 gallons in round figures).
The given multiplier is applicable only where the pipe is
new and in good condition. For rough pipe the multiplying
3
factor should be upped from 2 /4 to 3.45. In other words,
Examples. rough 20-in. pipe will require 20 ¥ 3.45 or 69 gallons of primer
3
Pipe 24in. in diameter will require 24 ¥ 2 /4 or 66 gallons per mile.
of primer per mile; It is hard to estimate the amount of spillage and waste.
3
/
Pipe 16in. in diameter will require 16 ¥ 2 4 or 44 gallons Temperature and relative humidity have an effect on the way
of primer per mile; and the primer goes on the pipe.