Versa-Matic N25 AIR OPERATED AIR OPERATED DOUBLE DIAPHRAGM PUMP - Manual (Page 4)

HG-CF-998 Rev. D - 03/27/03
Page 3
PRINCIPLE OF PUMP
OPERATION
This ball type check valve pump is powered by
compressed air and is a 2:1 ratio design. The
inner side of one diaphragm chamber is alter-
nately pressurised while simultaneously ex-
hausting the other inner chamber. This causes
the diaphragms, which are connected by a com-
mon rod secured by plates to the centers of the
diaphragms, to move in a reciprocating action.
(As one diaphragm performs a discharge stroke
the other diaphragm is pulled to perform the
suction stroke in the opposite chamber.) Air
pressure is applied over the entire inner surface
of the diaphragm while liquid is discharged
from the opposite side of the diaphragm. The
diaphragm operates in a balanced condition
during the discharge stroke which allows the
pump to be operated at discharge heads of over
500 feet (152 meters) of water.
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 pres-
sure regulating device to maximize diaphragm
life.
Alternate pressurising and exhausting of the
diaphragm chamber is performed by an exter-
nally mounted, pilot operated, 2 way type
distibution valve. When the spool shifts to one
end of the valve block body, inlet pressure is
applied to one chamber and the other diaphragm
chamber exhausts. When the spool shifts to the
opposite end of the valve body, the pressure to
the chambers is reversed. This alternating move-
ment of the spool inside the valve body is con-
trolled by a pilot air pressure signal held against
the diaphragm connecting rod, between seals in
the diaphragm shaft bushes. This signal is re-
leased, triggering the movement of the spool,
when pilot holes in the diaphragm connecting
rod align with the held pilot signal, sending the
signal to exhaust, which in-turn causes a pres-
sure imbalance around the spool, sending it to
the opposite end of the valve body. This simuta-
neously sends inlet pressure to the opposite
chamber.
The chambers are connected with manifolds
with a suction and discharge check valve for
each chamber, maintaining flow in one direction
through the pump. The 2:1 ratio discharge pres-
sure is generated by simultaneously delivering
air inlet pressure to alternate sides of a central
air diaphragm, the chambers either side of this
central diaphragm are pressurised and exhausted
in conjunction with the main diaphragm cham-
bers.
INSTALLATION
The typical installation shown in FIG. 1 is only a
guide to selecting and installing system
components. Your installation will depend on
the type of fluid being pumped and your
application needs. To reduce the risk of serious
bodily injury and damage to property, never use
fluids in this pump which are not compatible
with the wetted components. Contact your local
distributor or the manufacturer for system design
assistance & compatibility if necessary.
Mount the pump in an upright position. Failure
to ensure an upright position may result in loss
of or poor priming characteristics. Ensure the
pump is securely mounted to avoid movement
and possible risk of bodily injury.
PRESSURE The pump delivers double the
pressure at the discharge outlet as the air
pressure applied at the air inlet.
NOTE: Pressure Regulator (H) should be
installed where air supply could exceed 125
psi.
SAFETY
Your BLAGDON PUMP is a high
performance unit capable of achieving
high outputs at high efficiencies. However, as
is common with pneumatic equipment, the
pump efficiencies is reliant upon the air being
clean, dry and filtered. Failure to comply with
these requirements may lead to loss of
performance and reduced component life and in
extreme cases, permanent damage to the pump.
To avoid leaks, ensure that all fluid connections
are tight. The use of PTFE thread tape correctly
applied should be used to ensure 100%
leakproof connections. Failure to ensure
100% sealability of the suction connection
could adversely affect suction performance.
If you are pumping hazardous fluids, or
operating the pump in an enclosed area, it is
essential that the exhaust from the pump is
piped away to a safe location. When pumping
hazardous fluids the above instructions must be
adhered to in order to ensure safe operating
procedures. (Under certain operating
conditions the failure of internal components
can lead to the pumped fluid being exhausted
via the pump exhaust outlet).
WARNING
NEVER place your hands over or near the
pump suction inlet. Powerful suction could
cause serious bodily injury.
FLUSH THE PUMP This pump was
tested with water containing an oil-based rust
inhibitor. If this solution could contaminate or
react with the fluid you are pumping, flush the
pump thoroughly with a solvent/detergent to
clean internal components. The solvent/
detergent must be compatible with the pump
materials of construction. Care should be taken
to flush the pump each time it is disassembled
for maintenance or repair.
CAUTION Ensure that only the
recommended grade of lubricating oil is used.
BLAGDON PUMPS require an SAE 10
lubricating oil. Other grades of oil may cause
the Air Logic System to operate intermittently,
thereby causing a loss of output and failure to
operate.
If the pump accelerates or is running too fast
due to a lack of fluid, then stop it immediately
by shutting off the air supply. A dry pump will
accelerate to a high speed causing wear to
elastomers.
If the fluid you are pumping tends to dry up or
set when it is not moving, then flush the pump
as often as necessary to prevent the fluid from
drying in the pump. Drain the pump thoroughly
before storing.
If feasible, invert pump to allow any fluid to
drain from the non-return valves
.
Installation Guide
Fig. 1