Pulsafeeder PULSAR Shadow Series, Инструкция по установке, эксплуатации и обслуживанию

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An inlet strainer, if the product is not a slurry. Pump check valves are susceptible to dirt
and other solid contaminants unless designed for that service, and any accumulation
can cause malfunction. The strainer should be located between the suction shutoff
valve and the pump suction valve. It must be sized to accommodate the flow rate and
the anticipated level of contamination. A 100-mesh screen size is recommended.
Vacuum/pressure gauges in the suction and discharge lines in order to check system
operation. Gauges should be fitted with protective shutoff valves for isolation while not
in use.
Piping weight must not be supported by valve housings or other portions of the reagent
head, as the resulting stresses can cause leaks. If appropriate, provide for thermal
expansion and contraction so that no excess force or moments are applied to the pump.
In piping assembly, use a sealing compound chemically compatible with the process
material. Users of sealing tape are cautioned to ensure that the entering pipe thread
ends are not taped, and that tape is removed from previously-used threads to the
maximum practical extent prior to re-use. Both new and existing piping should be
cleaned, preferably by flushing with a clean liquid (compatible with process material) and
blown out with air, prior to connection to the pump.
4.3 Suction Pressure Requirements
Although PULSAR Shadow® metering pumps have suction lift capability, a flooded
suction (i.e., suction pressure higher than atmospheric pressure) is preferable whenever
possible. The pump should be located as close as possible to the suction side reservoir
or other source.
For fluid with a vapor pressure of 5 psia or less (at operating temperature) the wet
suction lift capability is ten (10) feet. If this requirement is not met, the pump will not
provide reliable, accurate flow. The Net Positive Suction Head Required (NPSHR) is
0.35 bar (5 psi).
The maximum inlet pressure is limited to 0.35 bar (5 psi) below the operating discharge
pressure.
Refer to Appendix I for procedures for the calculation of suction pressure.
4.4 Discharge Pressure Requirements
All PULSAR Shadow® Metering Pumps are designed for continuous service at the rated
discharge pressure. If system suction pressure were to exceed system discharge
pressure (a condition sometimes described as “pumping downhill”), flow would be
generated (siphoning) in addition to that caused by the pump, resulting in a reduction in
accuracy and loss of control over the metering process. To prevent this condition,
commonly referred to as “flowthrough”, the discharge pressure must exceed suction
pressure by at least 0.35 Bar (or 5 psi). This can be achieved where necessary by the
installation of a backpressure valve in the discharge line.
Damage to the pump will occur if operated at pressures beyond the maximum rating.
Refer to Appendix I for procedures for the calculation of discharge pressure.