Pressure Loss - Total Control Systems 700-20 Engineering Manual

J) Pressure Loss
The pressure drop is the difference between of the inlet and outlet pressure of the flow meter
while operating. When measuring a liquid, the pressure drop will increase as the flow rate
increases. When the metering system has accessories such as an air eliminator or valve,
these items will be approximately the same pressure drop through equivalent size meter.
3
2.5
2
1.5
1
0.5
0
0 10
EXAMPLE:
A 700-20SP flow meter, air eliminator, strainer and preset valve. Operating at 80 GPM on a
2000 SSU lubricating oil.
Flow Meter:
Air Eliminator/Strainer:
Preset Valve:
SSU
CPS Saybolt
Centipoise Universal
1 31
2 34
4 38
7 47
10 60
15 80
20 100
25 130
30 160
40 210
50 260
60 320
70 370
80 430
90 480
100 530
120 580
140 690
160 790
180 900
Centipoise
Centistokes =
Specific Gravity
PRESSURE DROP CURVE
32 SSU SOLVENT
20 30 40 50 60
PERCENT OF FLOW RATE
1.5 PSI x 4.0 = 6 PSI Pressure Loss
1.5 PSI x 4.0 = 6 PSI Pressure Loss
1.5 PSI x 4.0 = 6 PSI Pressure Loss
Total Pressure Loss is 18 PSI
VISCOSITY CONVERSION
(Specific Gravity = 1)
SSU
CPS Saybolt
Centipoise Universal
200 1,000
220 1,100
240 1,200
260 1,280
280 1,380
300 1,475
320 1,530
340 1,630
360 1,730
380 1,850
400 1,950
420 2,050
440 2,160
460 2,270
480 2,380
500 2,480
550 2,660
600 2,900
700 3,380
800 3,880
70 80 90 100
SSU
CPS Saybolt
Centipoise Universal
900 4,300
1,000 4,600
1,200 5,620
1,300 6,100
1,400 6,480
1,500 7,000
1,700 8,000
1,800 8,500
1,900 9,000
2,000 9,400
2,200 10,300
2,400 11,200
2,500 11,600
3,000 14,500
3,500 16,500
4,000 18,500
5,000 23,500
5,500 26,000
6,000 28,000
6,500 30,000
Centipoise = Centistokes x Specific Gravity
- 9 -
CONVERSION FACTOR
SSU Multiplier
30 = 1.0
100 = 1.5
500 = 2.5
1000 = 3.2
2000 = 4.0
3000 = 4.7
4000 = 5.0
5000 = 5.5
7500 = 6.5
10000 = 7.0
25000 = 10.0
50000 = 13.5
SSU
CPS Saybolt
Centipoise Universal
7,000 32,500
8,000 37,000
8,500 39,500
9,000 41,080
9,500 43,000
10,000 46,500
15,000 69,400
20,000 92,500
30,000 138,500
40,000 185,000
50,000 231,000
60,000 277,500
70,000 323,500
80,000 370,000
90,000 415,500
100,000 462,000
125,000 578,000
150,000 694,000
175,000 810,000
200,000 925,000