Pulsafeeder Pulsar Shadow - Manual (Page 43)

A) Discharge Setup
The pulsation dampener may be precharged with air or nitrogen. When properly precharged the
diaphragm is positioned against the bottom liquid chamber. It is therefore necessary to drain all
liquid below the diaphragm and vent to atmospheric pressure when precharging.
Use the precharge pressure as determined from the pulsation dampener selection and sizing
procedure (Catalog No. 211). This can vary from 50 to 80% of mean line pressure in
accordance with fluctuation level selected. The pulsation dampener is now ready for service
and the diaphragm will move to a neutral position as liquid enters the chamber.
Use the following to complete a Pre Charge Procedure for Discharge Installation
1. Calculate the precharge pressure
a. Mean Line Pressure (PSIG) + Atmospheric Pressure = Absolute Pressure (PSIA)
b. Absolute Pressure (PSIA) x Precharge Percentage (80% max) = Pressure Absolute
c. Pressure
Absolute – Atmospheric Pressure = Precharge Pressure (PSIG)
2. Isolate the pulsation dampener from the process line.
3. Carefully drain off process fluid by opening a drain valve (see recommend piping
arrangement).
4. Apply precharge pressure (additional liquid may drain as diaphragm moves).
5. Close drain valve.
6. Place
the pulsation dampener in the process stream.
B) Suction Setup (Flooded Suction)
Charge the pulsation dampener with adequate pressure to overcome the static suction head.
Start up the pump. Depress the stem on the charge valve, but only during discharge strokes of
the pump, until the gauge indicates pressure pulses. The diaphragm has now centered allowing
the pulsation dampener to accumulate liquid while the pump is discharging. If too much air
becomes released and the gauge will not indicate pressure pulses, recharge the pulsation
dampener and repeat the procedure.
Use the following to complete a Pre Charge Procedure for Suction Installation
1. Isolate accumulator from line.
2. Carefully drain off process fluid by opening a drain valve
3. Apply 5-10 psi precharge pressure (additional liquid may drain as diaphragm moves).
4. Close drain valve.
5. Bleed off all pressure on the pulsation dampener.
6. Open the valve to put pulsation dampener in stream.
7. Push in on the stem of the charging valve during the discharge stroke of the pump and
release during the suction stroke.
8. Continue this for about 10 times and observe the compound gauge. As accumulator
functions, the needle will go from pressure to vacuum.
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