How much does the water in a pipe weigh?
Water weighs about 8.34 pounds per gallon.
1 1/4 pipe 20 feet long holds 1.84 Gallons about 15.35 lbs.
2 1/2 inch pipe 20 feet long holds 3.67 Gallons about 30.60 lbs.
3 inch pipe 20 feet long holds 7.34 Gallons about 61.22 lbs.