Solenoid valves and gravity fed system pressures

By Beta Valve on Thu 09 May 2019 in Miscellaneous

Solenoid valves are commonly used for many applications described as a gravity fed systems, examples of such systems are header tanks and low pressure closed circuit systems.  The base of a gravity fed system is that gravity works with height.

 

Gravity is indeed a measurement of acceleration, the standard unit is 1m/s2 (meter per second squared). Of course there are small changes and/or anomalies depending on where you are in the world however it is generally agreed to be 9.81m/s2.

 

It is with this in mind that we realise that the pressure differences in gravity fed systems is purely generated from the height of the fluid alone. The higher the fluid the higher the pressure generated and both are directly proportional to each other and are totally unaffected by the pipe or tube diameter. (Although care must be taken on pipe diameter with regards to flow requirements. )

This table details the water pressure against height for gravity fed systems. 

Height of water column
Meters
Feet
1
3.3
2
6.6
3
9.8
4
13.1
5
16.4
6
19.7
7
23
8
26
9
30
10
33
12
39
14
46
16
82
18
59
20
66
25
82
30
98
35
115
40
131
50
164
60
197
70
230
80
262
90
295
100
328
Pressure
kPa
Bar
psi
9.8
0.1
1.4
19.6
0.2
2.8
29
0.3
4.3
39
0.4
5.7
49
0.5
7.1
59
0.6
8.5
69
0.7
10.0
78
0.8
11.4
88
0.9
12.8
98
1.0
14.2
118
1.2
17.1
137
1.4
19.9
157
1.6
23
177
1.8
26
196
2.0
28
245
2.5
36
194
2.9
43
343
3.4
50
392
3.9
57
491
4.9
71
589
5.9
85
687
6.9
100
785
7.8
114
883
8.8
128
981
9.8
142