ITT Goulds Pumps 3500XD, Инструкции по установке, эксплуатации и обслуживанию

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5.4 Seal/vacuum flush
(Refer to Figure 20 and 21)
Seal and flush water is manually controlled with a Safematic seal water monitoring unit. The seal water
flow to the bearing frame cooling coil and then to the mechanical seal is monitored with a 0-2 GPM flow
meter and alarm. The seal water from the mechanical seal outlet is directed to the gland flush connection
or stuffing box flush connection. Seal water required is 1-1½ GPM. A second 0-2 GPM flow meter is sup-
plied to provide 1-2 GPM directly to the Model 3500XD vacuum chamber. A third flow meter (0-4 GPM)
with alarm provides approximately 2 GPM of make-up water directly to the vacuum pump (Fig. 20).
Check valves are provided to prevent stock from flowing back into the seal and flush water control unit.
The water supply to the seal and flush water monitoring equipment should be clean filtered water with a
maximum particle size of 50 microns, a maximum temperature of 100° F (40° C) and supplied at mini-
mum pressure of 50 PSIG (3.5 bar). The seal water flow indicators for the mechanical seal and the vac-
uum pump are equipped with
flow switches, which are set to give an alarm if the flow falls below 50% of the set point. The Model
3500XD pump will not start unless the seal water flow is above the minimum.
For design pulp consistencies at 10% and lower it is not neccessary to utilize a vacuum pump with the
Model 3500XD. In this situation only two seal flush water flow meters are required. The flow meter serv-
icing the vacuum pump is not required (Fig. 21).
CAUTION:
Never operate the pump without liquid supplied to mechanical seal. Running a mechanical seal
dry, even for a few seconds, can cause seal damage and must be avoided. Physical injury can
occur if mechanical seal fails.
Figure 20: With vacuum pump
5.4 Seal/vacuum flush
3500XD Installation, Operation and Maintenance Instructions 29