Pipeline ancillaries Separators and insulation jackets
10
Steam sizing example - lb/h, psi g and ft/s The steam sizing example below has been based on imperial O/D tubing delivering 1100 lb/h of steam at 87 psi g. 1. Plot point A where the steam pressure and flowrate cross, e.g. 87 psi g @ 1100 lb/h: Draw a horizontal line. 2. Select line size . Any separator curve that is bisected by this line at a velocity below 27 m/s will operate at near 100% efficiency. For this example choose a 2" (DN50) separator, point B . 3. Ascertain velocity . Line velocity for any size can be determined by drawing a vertical line upwards from the point of intersection. From point B in this example the line crosses the velocity axis at 49 ft/s. Note: a velocity correction factor needs to be applied - Please refer to the correction factor table below. For this example the velocity correction factor is 1.22 for a 2" imperial O/D tube therefore the velocity in this example would be 18.3 m/s. 4. Pressure drop . Where the line extended from point B crosses the line C – C , plot a horizontal line. Now drop a vertical line from point A . The point of intersection, D , is the pressure drop across the separator, i.e. approximately 0.17 psi. 5. Separators should be selected on the basis of the best compromise between line size, velocity and pressure drop for each application.
Flow velocity ft/s
Steam pressure psi g
0
29
58
87
110 5
32
49
65
82
98
111 131
2"
B
1½"
A
¾" and 1"
½"
C
D
10.7 59
C
Pressure drop across separator psi (approximate)
Separator size
½"
¾"
1"
1½" 1.61 1.00 1.37 1.38 1.46 1.22
2"
I/D (in) Factor I/D (in) Factor I/D (in) Factor
0.62 1.00 0.37 2.83 0.59 1.11
0.83 1.00 0.62 1.45 0.75 1.13
1.05 1.00 0.87 1.45 0.98 1.13
2.07 1.00 1.87 1.22 1.93 1.15
Schedule 40 pipe
Velocity correction factor table
Imperial O/D tubing
Hybrid DIN 11850 pipe
TI-P023-59 CMGT Issue 7
Page 5 of 7
CS10-1 Stainless Steel Clean Steam Separator
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