Page 9
13
VWP 160-3 / 250-3
14
6. Coolant
6.1 External cooling (pict. 13)
The cooling supply is connected to the
hose connection (C) and the water jacket
(Y
4
) is filled by pressing the spring loaded
priming valve (U
4
).
Use only clean and filtered water
for the cooling. Dirt particle and
aggressive water can lead to prema-
ture wear in the cooling system.
The valve should be depressed until the
cooling water flows from the outlet hose
connection (D). The outlet hose may then
be connected. If rigid pipework has been
connected to the inlet and outlet points
then the vent valve (U
8
) should be re-
moved prior to filling. This should be re-
placed when the cooling water flows from
the opening. The water outlet pipe should
exert no backpressure on the water jacket.
According to requirement of the process, the operating temperature can be adjusted by the water-valve (U
3
) like follows:
•
Turn the regulation knob clockwise
➝
the operating temperature of the pump will be decreased
•
Turn the regulation knob anti clockwise
➝
the operating temperature of the pump will be increased
Operating temperature can be seen on the thermometer (T).
If for any reason the temperature should rise above the set point the high temperature cut out (U
1
) will shut the pump down at a
temperature of 75°C. This temperature is set in our works and should not be adjusted. Higher operating temperatures are possible
for certain processes, but should be referred back to our works.
In order to keep the thermostatic valve clean a dirt filter is fitted (U
5
). The valve should be cleaned periodically depending on the
water quality. To do this unscrew the nut and clean the element.
6.2 Radiator cooling (pict. 14)
Fill the water jacket with coolant via filler (H
4
), taking care not to pressurise the water jacket. Coolant should be water/glycol 1:1.
We recommend following types of glykol: Aral anti-frost A, BP anti-frost X 2270 A, Glacelf, Glysantin, Glycoshell AF 405, Veedol
Antifreeze. The water must be ph-neutral. The liquids should be well mixed before fill in. A simple pouring together is not sufficient
because of their different specific weights. Yoo can see the quantity of coolant in the data (9.7). For other coolants please contact
Rietschle. The coolant can be drained by opening the drain valve (K
4
) near the base of the water jacket (Y
4
) and unscrewing the
filler plug (H
4
) to allow venting.
6.2.1 Cooling liquid monitoring
The coolant level is automatically monitored by a level switch (V
4
) which switches the pump off it the level falls below the minimum.
The safety thermostat (U
1
) controls the maximum temperature of the coolant.
VWP 160-3 / 250-3:
When the pump is running and the coolant temperature reaches that set on the thermo sensor in the circuit, the 3-way-valve opens
automatically towards the cooler. The permissible temperature can be adjusted by the regulation knob of the thermostatic
valve (U
7
):
•
Turn the regulation knob clockwise
➝
the operating temperature of the pump will be decreased
•
Turn the regulation knob anti clockwise
➝
the operating temperature of the pump will be increased
Operating temperature can be seen on the thermometer (T).
VWP 400-3:
When the pump is running the operating temperature thermostat (U
1
) controls the switching on and off of the cooling fan to maintain
the pump at constant temperature.
VWP 160-3
➝
400-3:
The safety temperature can be set according to process requirements within the range of 65° - 100° C. The safety thermostat limits
the maximum temperature in the water
jacket to 75°C, above which pump is shut
down automatically. Higher temperature
(adjusted by the company) than 75°C are
possible for certain processes by refer-
ence to our offices. In the event of high
temperature shut down the cooling sys-
tem should be checked.
If the location of the pump is such that
there is a danger of freezing then appro-
priate measures should be taken for both
external cooling and radiator cooled ver-
sions.
