McElroy 2CU, Operator'S Manual

Page: 29 / 34

Variable Definitions
O.D. = Outside Diameter
t = Wall Thickness
∏
= 3.1416
SDR = Standard Dimensional Ratio
IFP = Manufacturer’s Recommended
Interfacial Pressure
Formulas
O.D.
t = ------------
SDR
AREA = (O.D. - t) x t x
∏
FORCE = AREA x IFP
REQUIRED FORCE = (O.D. - t) × t ×
∏
× IFP + DRAG
Example
Pipe Size = 2" SDR 11
O.D. of Pipe = 2.37"
SDR of Pipe = 11
Recommended Interfacial Pressure = 75 PSI
Using a Model 2CU Fusion Unit
O.D. 2.37
t = ------------- = --------------- = 0.2154
SDR 11
REQUIRED FORCE = (O.D. - t) × t ×
∏
× IFP + DRAG
REQUIRED FORCE = (2.37 - .2154) × .2154 ×
3.1416
× 75 + DRAG = 109 + DRAG
Using the Chart (section 7-2):
From the table you see that:
20 ft/lbs of Torque = 75 lbs Force
and
30 ft/lbs of Torque = 140 lbs Force
The chart on the next page will assist you in interpolating the proper value of
torque to use with the torque wrench.
Interpolating between these two values give approximately 25 ft/ lbs
Torque.
FUSION FORCE = 25 ft/lbs + Drag (measured in ft/lbs)
TX02576-12-8-05
7 - 1
Determining Fusion Force
PH03
12
3-1
2-5-05
Torque Wrench 2CU
Reading Jaw Axial Force
(Ft Lb) (Lb)
10 35
20 75
30 140
40 190
50 230
60 270
70 310
80 350
90 380
100 420