Graco Manzel 88 Pumps User Manual

Manzel® Model 88 Pump

DESCRIPTION

The Model 88 Pump is a heavy-duty precision metering pump
capable of accurately pumping small flows of either mineral or
synthetic oil to machinery injection points. The single-piston
pump is mechanically driven from a camshaft in the reservoir
and is adjustable from 1 to 27 drops per stroke, depending on
the piston size. The pump can develop pressures up to 7500
psi, depending on the piston size. All working parts are totally
enclosed away from dirt, water, and impurities and self-lubricated
at all times by the fluid in the reservoir.

Model 88 Pumps are designed for use in Manzel® Model 55 and
76 Box Lubricators, and in Mega, Lincoln and Premier Model 55
Box Lubricators. The output ranges vary slightly depending on the
lubricator.

Model 88 Pumps are rugged, heavy duty units. Each pump
includes a precision machined steel sleeve fitted with an alloy
steel piston.

The pump is actuated by a hardened steel roller - rocker following
a cam for low wear and longer life. The visual sight well is one­piece injection molded material that is impervious to ultra-violet
rays, and mineral and synthetic oils.

Three (3) piston sizes are available to produce outputs up to 27
drops per stroke in Manzel Box Lubricators and up to 20 drops per
stroke in Mega, Lincoln and Premier Model 55 Box Lubricators.

FEATURES/BENEFITS

ball is concurrently unseated and lubricant is drawn into the piston
cylinder from the sight well. This action creates a pressure reduction
(vacuum) in the air- tight sight well, causing lubricant from the
reservoir to be drawn into the well until pressure is equalized. On
the piston upstroke, the oil in the piston cylinder reseats the inlet
shutoff ball and is forced out through the discharge check valve to the
machine injection point.

The number of drops seen falling in the sight well equals the amount
of oil discharged by the pump. Pump volume can be adjusted by
means of an external screw. This changes the length of the piston
stroke which changes the pump discharge volume.

Rugged construction for high performance and durability•
Suction and gravity/pressure feed models for application •
flexibility
Pump output is easily adjustable•
Hardened cam roller adds to pump and cam life•
One piece sight glass means fewer leak path and seal •
points

OPERATION

Pumps With Vacuum Feed
(Sight Glass Type)

Rotation of the lubricator cam actuates the pump rocker arm
assembly to operate the pump piston. On the piston downstroke,
spring force is exerted on the piston causing it to follow the cam. As
it moves down, a pressure reduction is created in the area between
the piston and the discharge check valve. The supply inlet shutoff

Manzel

®

Model 88 Pump

Pumps With Gravity Feed and Pressurized
Supplies

L51025

Calculate Pints Per Day As Follows:

Rotation of the lubricator cam actuates the pump rocker arm
assembly to operate the pump piston. On the piston downstroke,
spring force is exerted on the piston causing it to follow the cam.
As it moves down, a pressure reduction is created in the area
between the piston and the discharge check valve. The gravity
feed or pressurized supply unseats the supply inlet shutoff ball
and fills the piston bore with lubricant. On the piston upstroke, the
oil in the piston cylinder reseats the inlet shutoff ball and is forced
out through the discharge check valve to the machine injection
point. Pump volume can be adjusted by means of an external
screw. This changes the length of the piston stroke which
changes the pump discharge volume.

Number of Drops/Min. X 1440 (Minutes in a Day) = Pints/Day
14115 (Number of drops in a Pint)

Calculate Minimum or Maximum Pump
Output Capacity

Input Speed X Pump Output X 1440
Gear Ratio (Min. or Max. (Min./day)
drops/stroke*)
14115 (Number of Drops in a Pint)

* Minimum and Maximum Drops Per Stroke Listed in
Specifications on the next page.

NOTE: For proper sizing select the appropriate
lubricator brand. Brand as well as piston
size will effect minimum and maximum
pump capacity.

The following example is a Manzel lubricator, electric motor driven,
300:1 internal ratio, 1/4" pump model 88. Solve for maximum flow:

1725 Motor Speed X Max. 12 drops X 1440 Min.
300:1 Gear Ratio per stroke
14115 (Number of Drops in a Pint)

Min. or Max. Pump Output

=

(Pints Per Day)

Max. 7.04

=

Pints/day

ADJUSTMENT

Pump discharge (output flow) can be adjusted within the min./
max. ranges as shown in the illustration. The adjustment is
linear. Therefore, positioning the screw midway will produce
one-half of the pump capacity. To adjust the flow, proceed as
follows:

Loosen adjusting screw locknut.1.

Turn the adjusting screw to the desired position and, with 2.

the pump operating, count the drops falling in the sight well
for a one-minute interval.

Tighten adjusting screw locknut.3.

To Calculate Minimum: Replace the maximum 12 drops per stroke
with the minimum 2 drops per stroke: (1.17 minimum pints per day)

*Should not reciprocate up and down as pump operates, on
pumps built beginning in January 1997.

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