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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.