ITT Goulds Pumps VIS, Инструкции по установке, эксплуатации и обслуживанию

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6 General
6.1 Operation at Shutoff Heads
In the usual application of vertical turbine pumps, no harm will result from operation under conditions of
static flowheads; however, not all installations are "usual" and, for this reason,
consideration should be given to any unit which may be subjected to this usage. The following points
should therefore be checked and resolved before putting the equipment into operation at or near shutoff
heads.
1. Thrust bearing capacity must be adequate.
2. If prolonged operation at no flow is contemplated, the problem of heat dissipation may become
acute, since the entire shutoff horsepower is converted to heat in the available fluid.
3. For high pressure units, stresses at shutoff heads should be investigated. This information may
be obtained from the factory upon request.
4. Certain impeller designs may have critical horsepower characteristics at low flows. Shutoff power
requirements should be examined for driver overloads.
5. It must be kept in mind that impeller shaft bearings depend on pumped fluid for lubrication. Fluid
temperatures, if raised excessively due to lack of flow, may impair lubrication efficiency and may
also damage the motor through the excessive heat.
To summarize, designs will easily accommodate most of the considerations listed above. However, to ob-
tain the best possible application, the factory should be notified at the time of order if operation at static
flow heads will be a possibility and this precaution must be observed to validate any warranties.
6 General
22 VIS Installation, Operation and Maintenance Instructions