MP Filtri ICM, User Manual

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50 Hydraulic Connection
for "Mini-mess’’ hoses. This information can be found in the manufacturers
catalogues. In the case of Mini-mess hoses, at 30 cSt these have a pressure
drop of around 10 Bar per meter per lpm of flow. So a 2m total hose length
would add a pressure drop of
2 × 10 × 0.2 = 4
Bar. (So in this case the
pressure-flow relationship is mainly dependent on hose resistance.)
•
Add the ICM pressure drop to that of the hoses, e.g.
4 + 0.4 = 4.4
Bar.
When the required pressure drop has been found:
•
See the figures at the start of this section for examples of where the ICM could
be connected.
•
If there is a pair of connections in the hydraulic circuit that operates with a dif-
ferential pressure near to that calculated, then the ICM can be connected there.
•
Alternatively, create the pressure drop by modifying the hydraulic system. For
example, insert a check-valve in the circuit with a 4 bar spring.
16
The "com-
ponent’’ could also be a filter, a restrictor or even a piece of piping if it has a
suitable pressure drop across it.
•
If none of these options is feasible, then an active flow controller will likely be
needed, see 15.3.
•
Otherwise connect the ICM across the points identified, taking care to maintain
an upward flow of oil through the unit (this reduces trapped air).
Of course in a real system the pressure and viscosity will vary with temperature
and operating conditions. But since the working flow range of the ICM is very
wide, this should not be a problem provided it remains within range. On the
graph the area between upper and lower lines represents the usable operating
region for the ICM, with the middle line being ideal. The differential pressure
and the viscosity can vary from the ideal, provided the system stays within the
upper and lower lines. This ensures the flow stays within the working range of
20 - 400 ml/min. It can be seen that the unit will accommodate a 20:1 variation
in either viscosity or differential pressure during operation.
16
In fact the ICM will work perfectly well at a lower flow, for example 100ml/minute, in which case a 2
Bar check-valve could be used.