Air Release Valve

1
SERIES VPA FILLING METERING PUMP
PRODUCT EDUCATION COURSE
2
Purpose of a VPA Filling Metering Pump
Imagine having an employee who constantly
measures out a precise dose of liquid whenever
its needed.
3
But a Series VPA Air-Operated Filling Metering
Pump is much more accurate
and it doesnt spill or drip. It also measures
a lot faster!
4
Uses for an Air-Operated Filling Metering Pump

1. Exact filling of a batch of containers.
2. Adding a precise amount of liquid to a mixture,
   container, or pipeline.
3. Deliver a regularly timed, repeatable dose.
4. Deliver a precise dose sporadically, when
   signaled by a control system or an operator.

5
How it Works

• There are three key components to Series VPA
  Air-Operated Metering Pump
• Check Valves
• Internal Piston
• Compressed Air, with 4-way air solenoid valve
  (not shown).

6
There are two chambers in the pump. The LIQUID
chamber, which fills with and discharges
liquid. The AIR chamber, where compressed air
is used to drive the piston.
7
Using controlled compressed air, the piston moves
to both fill and discharge the pump. Proper flow
filling and discharging is assured by the
check valves. Lets look at it, step-by-step
8
First, we need to draw liquid into the pump from
the supply source.
To accomplish this, compressed air is directed
into the air chamber on top of the piston.
9
The compressed air begins to act on the piston,
and the piston starts to move. Notice that the
air beneath the piston in the liquid chamber is
being forced out through a vent. Likewise, the
air beneath the piston in the air chamber is
expelled through the 4-way air solenoid valve.
10
As compressed air forces the piston down, a
vacuum is created in the upper section of the
liquid chamber. This vacuum draws open the inlet
check valve, and liquid is sucked into the
chamber.
11
The piston continues its stroke. Negative
pressure in the liquid chamber continues to draw
the liquid in.
12
This negative pressure also draws on the outlet
check valve, assuring that it will stay closed
during this fill stroke.
13
The piston moves until it reaches the limit stop.
This limit stop is a screw that can be set to
change the volume of the dose.
14
Compressed air flow stops momentarily while the
air control valve switches. Both inlet and outlet
check valves are closed. Now we see that the
pump is fully loaded with liquid, ready to
discharge and deliver the precise amount in the
liquid chamber.
15
The 4-way air control valve switches, and now
begins to direct compressed air below the piston
in the air chamber.
16
Air pressure beneath the piston begins the
discharge stroke.
17
As the piston moves up, liquid pressure forces
open the outlet check valve, and discharge begins.
18
The piston continues moving, the outlet check
valve is fully openthe pump is discharging.
19
Notice that the air above the piston the air
used to fill the pump is discharged through the
same vent used for filling. (Its all controlled
by the 4-way air solenoid valve.)
20
Throughout the discharge stroke, the inlet check
valve remains closed, even though the inlet
pipeline has liquid present.
21
When the piston reaches the stop in the air
chamber, the discharge stroke is complete. The
VPA Metering Pump has delivered a precise amount
of liquid.
22
The pump is primed, and ready for the next fill
stroke. With liquids similar to water, the
pump can cycle up to 10 times per minute. Cycle
rate is reduced as liquid viscosity increases.
23
Series VPA is unlike any other metering pump.
Each cycle delivers a precise amount Volume is
adjustable via built-in Limit Stop
Self-priming Controlled by common, inexpensive
4-way air control valve
24
Versatile Sizing
Plast-O-Matic Series VPA chemical metering pumps
are available with maximum per cycle capacities
of 7 ounces, 10 ounces, 32 ounces and 128
ounces. Using the Limit Stop, the per cycle
discharge capacity can be infinitely adjusted
from its maximum to 20 of its maximum. For
example the 128 ounce pump can be adjusted to
discharge anywhere between 25 and 128 ounces per
stroke.
25
and incredible accuracy!
While the pump discharge adjustment is simple, it
is recommended that the discharge amount be
physically measured. Once the measured amount
is set and checked the accuracy of the discharge
repeatability is approximately 1/2 of 1. To see
a brief video of how the pump functions and the
limit stop is adjusted, please click here.
(must have internet connection)
26
Rugged construction
Series VPA pumps are available in PVC, Natural
Polypro, and Kynar PVDF. It is also offered with
PTFE cap seals, and stainless steel cylinder
walls. In lab tests with water, pumps with PVC
cylinder walls will last between 100,000 and
300,000 cycles. Over 1,000,000 cycles is achieved
in testing with optional stainless steel cylinder
walls.
27
Proximity sensors are available to verify
position on all metering pump sizes. These can be
used to power a relay, stage a filling line,
signal a computer, signal a fill station counter,
or signal virtually any other process control.
Switches are ideal to verify that the pump has
discharged or retracted, or both.
28
So what is this pump used for?
Applications that need terrific accuracy.
Applications where a dose must be delivered but
only when signaled to do so. Its not a
continuous pump, it wont do what a double
diaphragm pump does. But no other pump will do
what the VPA does. For example Deliver an
exact amount of additive to paint cans in a
filling line. Pump and discharge a
preservative/lubricant to railroad ties, as part
of an automated system using an electric eye.
Fill bags with reactive liquid, causing the bags
to expand and control the force of dynamite in
mining operations. the applications for Series
VPA are limited only by your imagination!
29
Series VPA Air-Operated Filling Metering Pump