Festo VZWM, Operating Instructions Manual

Page: 28 / 88

VZWM
Festo VZWM 0612NH English
28
13 Ch a r ac teri s ti c cu rve s
Calculating the pressure shock
1. Make a note of all known values of the tubing system in the grey fields of the
following table.
Si z e s o f the
t u bin g s y s te m
Unit V a l u e Re s pon s ible
no m o g r am
N o m o g r am
a xi s n um ber s
Flow velocity [m/s] Nomogram A
(
è Fig 10)
5
Tubing length [m]
( è Fig.10)
4
Valve closing time [min] 2
Pressure shock [mFs] 1
Flow [m
3
/h]
Nomogram B
(
è Fig 10)
6
Tubing diameter [mm] or
[inch]
( è Fig.10)
7
Flow velocity [m/s] 8
Sound velocity of the
medium used [m/s] 9
Pressure shock [mFs] 10
Fig.9
2. Note the values of the table as points on the relevant axis of the nomogram
( è Fig.10
1
).
3. Connect two points of axes lying next to each other with a straight line.If this
line is lengthened, a further point can be defined (
è
Fig.10
2
).
4. Repeat points 2 and 3 with the new point gained by the lengthening.The result
will be the relevant pressure shock ( è Fig.10
3
).
5. Note the pressure shock value ascertained in Fig.9 unit:
fluid level per metre [mFs].