Page 80 - Pipeline Rules of Thumb Handbook

Construction 67

How many welds will the average welder make per hour?

.
Where stringer beads have been run, the average welder N = 415 welds per hour or about 42 welds per 10-hour day.
can complete about 140 inches of weld per hour on ordinary
one-fourth-inch wall line pipe. To find the average number of On large diameter pipe where wall thickness has been
welds per hour, divide the circumference of the pipe into 140. increased, welders average about 100 inches of completed
weld per hour.
140
N = wherecircumference C () = pipe diameterin
C Example. How many welds per hour will a welder com-
.
inches times 314
plete on 30-inch line pipe if the stringer beads have been
run?
Example. How many welds per hour will a welder com-
3
plete on quarter-inch wall 10 / 4 -inch line pipe, if the stringer
100
beads have been run? N =
C
140 100 100
.
N = N = ) = = 11 welds per hour or 11 welds
.
30
(10 75. )(3 14. ) ()(3 14. 94 2 per 10 hour day
140
N =
.
33 76

How much welding rod is required for a mile of schedule 40 pipeline?

Rule. For 40-foot joints of schedule 40 pipe, multiply the For 40-foot joints:
1
nominal pipe diameter by 22 / 2 ; the answer is pounds of elec-
trode per mile of pipeline. 40
225 ¥ = 300 pounds per mile for 30-foot joints.
30
Example. 6-inch pipe:
The rule is based on standard weight (schedule 40) pipe,
=
6 ¥ 221 2 135 pounds per mile. and the usual number of passes, which varies from two for
small pipe up to four for 16 inches; larger pipe is usually
Example. 10-inch pipe, 30-foot joints: thinner wall; the rule includes an allowance for wastage.

10 ¥ 221 2 = 225 pounds per mile

How many pounds of electrodes are required per weld on line pipe?

Divide the nominal pipe size by two and multiply the result 10
1
by one-fourth pound. Pounds of electrode= ¥ .25 = .25 pounds per weld.
2
N
Pounds of electrode= ¥ .25 Example. How many pounds of electrode will be used per
2 weld on 24-inch line pipe?

Example. How many pounds of electrode will be used per Solution. Pounds of electrode = 12 ¥ .25 or 3 pounds
weld on 10-inch line pipe? per weld.