SANDPIPER ET1 1/2 - M - Manual (Page 4)

et15mdl3sm-rev0614 Model ET1 1 /
2
-M Type 3 Page 3
CONTAINMENT DUTY Type 3
SERVICE AND OPERATING MANUAL
Original Instructions
ET1½ - M
PRINCIPLE OF OPERATION
This ball check valve pump is powered by compressed air and is a 1:1
pressure ratio design. It alternately pressurizes the inner side of one diaphragm
chamber, while simultaneously exhausting the other inner chamber. This causes the
diaphragms, which are connected by a common rod, to move endwise. Air pressure
is applied over the entire surface of the diaphragm, while liquid is discharged from
the opposite side. The diaphragm operates under a balanced condition during the
discharge stroke, which allows the unit to be operated at discharge heads over 200
feet (61 meters) of water head.
Since the diaphragms are connected by a common rod, secured by plates to the
center of the diaphragms, one diaphragm performs the discharge stroke, while the
other is pulled to perform the suction stroke in the opposite chamber.
For maximum diaphragm life, keep the pump as close to the liquid being pumped
as possible. Positive suction head in excess of 10 feet of liquid (3.048 meters) may
require a back pressure regulating device. This will maximize diaphragm life.
Alternate pressuring and exhausting of the diaphragm chamber is performed
by means of an externally mounted, pilot operated, four-way spool type air
distribution valve. When the spool shifts to one end of the valve body, inlet air pressure is
applied to one diaphragm chamber and the other diaphragm chamber exhausts.
When the spool shifts to the opposite end of the valve body, the porting of chambers
is reversed. The air distribution valve spool is moved by an internal pilot valve which
alternately pressurizes one side of the air distribution valve spool, while exhausting
the other side. The pilot valve is shifted at each end of the diaphragm stroke by the
diaphragm plate coming in contact with the end of the pilot valve spool. This pushes
it into position for shifting of the air distribution valve.
The chambers are manifolded together with a suction and discharge check valve
for each chamber, maintaining flow in one direction through the pump.
This SandPIPER pump differs from others in that it utilizes four diaphragms
instead of two. The two rod-connected diaphragms are the driver diaphragms,
and the other two (outermost) diaphragms are the actual pumping diaphragms.
Each driver diaphragm (of Neoprene or other elastomer), and the pumping
diaphragm (of TFE), are separated by a chamber filled with liquid which transmits the
reciprocating motion of the driver diaphragm to the pumping diaphragm. The
pumping diaphragms, create the alternating suction and discharge action to each
outer diaphragm chamber. The pumping diaphragms are the only ones in contact
with the liquid being pumped.
INSTALLATION & START-UP
Locate the pump as close to the product being pumped as possible, keeping
suction line length and number of fittings to a minimum. Do not reduce line size.
For installations of rigid piping, short flexible sections of hose should be installed
between pump and piping. This reduces vibration and strain to the piping system.
A Warren Rupp Tranquilizer ® surge suppressor is recommended to further reduce
pulsation in flow.
This pump was tested at the factory prior to shipment and is ready for
operation. It is completely self-priming from a dry start for suction lifts of 10-15 feet
(9-14 meters) or less. For suction lifts exceeding 15 feet of liquid, fill the chambers
with liquid prior to priming.