Component Materials; Metering Capacity - Ecolab PDP II Notice Technique

13.5

Component materials

Component part
Valves, pump head
Seals
Valve ball
Valve spring
Housing
13.6

Metering capacity

To achieve accurate metering, the following points should be noted:
a) All metering data is related to measurements with water at 20 °C with control air pressure
6 bar. The metering capacity depends also on the viscosity and the specific gravity of the
metering product. The exact capacity is calculated by capacity measurement (see
chapter 9.2).
b) To achieve a high degree of free flow metering accuracy, a pressure maintenance valve
(or metering valve) should be used to produce counter pressure of at least 1 bar and to
hold it as static as possible.
c) If there is primary pressure on the suction side, the differential pressure between the
suction side and the pressure side should be at least 1 bar. The head of water on the
metering pump must be safeguarded by an appropriate valve arrangement.
Neither a pressure maintenance valve nor a metering valve can be regarded as a means of
NOTE
closing off the flow completely.
Only adjust the metering stroke of a pump that is in use if the stroke adjustment screw is
WARNING
not under pressure.
417101420_pneum_II.doc - 48 -
material
PP
VITON B (standard)
EPDM
Stainless steel
Hastelloy
PPO / PP
Rev. 4-07.10