Ampco Pumps Company ZP3 Series Manual

Ampco ZP3 Series (Addendum)
Positive Displacement Pumps
Installation and Maintenance Manual

Ampco Pumps Company
November 2011
Pump Disassembly
1) Start by removing the cover nuts with an appropriate wrench (Figure 1). During disassembly
place all parts on a clean, protected surface with finished surfaces and seal faces facing up.
Tap the cover off using a soft mallet. Remove the cover o-ring and inspect it.
2) Loosen each rotor nut using the appropriate size wrench and a non-metallic wedge to keep
the rotors from moving (Figure 2). Unthread each nut and disassembly the nut assembly
(Rotor nut, Bellville washer and retaining o-ring).
Figure 2: Rotor Removal
3) Remove the rotors by orientating them perpendicular to each other and then pulling them
out. It is important to be cautious with the rotors so that they are not damaged in any way. If
rotors are difficult to remove, use a nylon or wood lever to pry them out without damaging the
body or the rotors. Use Figure 3 to ensure that all parts are removed.
Part
1Rotor Nut Assembly
2Rotor Nut O-ring
3ZP3 Rotor
4Rotating Seal O-ring
5Rotating Seal
6Stationary Seal
7Stationary Seal O-ring
8Wave Spring
Wedge Rotor Nut Assembly
Page 2
1
2
3
4
5
6
7
8
Rotor Nut
Bellville Washer
Retaining O-ring
Figure 3: Exploded View
Figure 1: Removing ZP3 Cover
Maintenance

Maintenance Ampco Pumps Company
Seal Assembly
1) Start by inserting the wave spring into the sleeve making sure that it sets below the
stationary drive pins (Figure 4). Insert a rotor key in the keyway on the shaft.
2) Slide the stationary seal o-ring into the body hub until it seats against the top of the sleeve
(previously installed). Align the slots on the stationary seal with the pins inside the hub. Press
the stationary seal into the hub until is seats on the spring; there should be noticeable spring
resistance when pushing on the seal.
3) Next install the rotating o-ring onto the rotating seal by stretching it (not rolling) onto the
rotating seal (Figure 6).
Wave
Spring
Align the
slot and pin
Figure 4: Inserting Spring
Figure 5: Stationary Seal Assembly
November 2011 Page 3
Figure 6: Installing the Rotating O-ring
12
Stationary Seal
O-ring

Page 4 November 2011
Maintenance Ampco Pumps Company
Pump Assembly
4) Slide the rotating seal onto the rotor hub (Figure 7) making sure to align the slots on the
seal to the drive pins in the rotor. Press the seal down until it seats inside of the rotor.
5) Slide the rotors on to the shafts until they seat against the shaft shoulder (Figure 8).
6) Install the Bellville washers in the rotor nuts in the orientation shown and hold them in place
using the small retaining o-rings (Figure 9). Install a rotor nut o-ring before threading the nut
onto the shaft.
Rotating Seal
Rotating Seal O-ring
Align
Figure 7: Inserting Rotating O-ring
Figure 8: Rotor Assembly
Rotor Nut
Bellville Washer
Retaining O-ring
Figure 9: Rotor Nut Assembly
Rotor Nut O-ring
Shoulder

Wedge
Page 5November 2011
Maintenance Ampco Pumps Company
Seal Assembly
7) Thread the nut onto the shaft and tightening it down using the appropriate wrench and a
non-metallic wedge to hold the rotor in place (Figure 10). Torque the rotor nuts down using
163 N-m (ZP3 30, See ZP2 manual for correct values) of force. Orientate the rotors as seen in
Figure 10 and Always tighten the first rotor positioned under the overlap of the opposing rotor.
Repeat with the second rotor in the same orientation.
8) Install a new cover o-ring and slide the cover over the studs making sure that the dowels in
the body are aligned with the correct dowel holes in the cover (Figure 11). Visually inspect to
ensure that the cover o-ring remained in place. Turn the cover nuts (clockwise) by hand and
fully tighten them using the appropriate wrench. Tighten the rotor nuts in an opposing manner,
as seen on Figure 11, so that the cover is evenly tightened to the body.
Figure 10: Rotor Assembly
Figure 11: Cover Assembly
Overlap

Maintenance Ampco Pumps Company
Page 6 November 2011
Pump Clearances
The performance of a ZP3 is based on the tight clearances between the pump body and the
rotors. These clearances are critical to ensure the pump performs up to the system
requirements. The clearance between the rotor and the back face of the body is referred to as
the backface clearance. Other clearances are shown in Figure 12 and should be in
accordance to Table 1. Use shims and a depth micrometer to measure the clearances.
Figure 12: Critical Pump Clearances
Table 1: Critical Pump Clearance Dimensions (Standard Rotors)
A (Backface Clearance)
B (Rotor to Body Clearance)
C (Front Face Clearance)
Note: For non-standard
rotors contact Ampco
A
(Backface Clearance)
B
(Rotor to Body Clearance)
C
(Front Face Clearance)
ZP3 Model Inch mm Inch mm Inch mm
6, 15, 18 .002 .05 .002 .05 .005 .13
30, 34 .002 .05 .002 .05 .005 .13
45, 60, 64, .004 .10 .005 .13 .008 .20
130, 134 .004 .10 .005 .13 .008 .20
180, 220, 224 .005 .13 .006 .15 .008 .20
210, 320 .005 .13 .010 .25 .011 .28
Measuring A
Cutaway
Measuring B Measuring C
Depth
Mic.

Maintenance Ampco Pumps Company
Page 7November 2011
Annual Maintenance
It is important to perform an annual maintenance check of the pump in addition to the
preventative maintenance procedures listed on pages 13 and 14. Annual maintenance
practices are as follows:
 Check the gear case bearings by measuring the shaft’s radial movement with a dial
indicator (Figure 22, A). If the movement is greater than or equal to the rotor-to-body
clearance found on page 28 (Table 8) the bearings should be replaced.
 Remove the gear casing cover (See page 21 for disassembly information) and inspect the
gears for wear and damage (Figure 22, B). Also check for backlash and looseness.
 Inspect the rotors for signs of wear and stress cracks around the areas defined in Figure
22, C. Replace, if necessary.
 Check the pump clearances detailed on page 28 to determine pump wear. Pump wear can
be compensated by increasing pump speed.
Figure 22: Annual Maintenance Checks
C
Check Check Gears
B
Check Bearings
A
Cleaning
All wetted parts are designed and manufactured to be acceptable by 3A Sanitary Standards.
The body, rotors, and seals can be easily disassembled and cleaned simply by removing the
cover and rotor nuts. Pump disassembly information begins on page (ZP2 Manual page16).
The ZP3 pumps is clean-in-place (CIP) capable allowing CIP solution to reach all surfaces
inside the pump. The fluid velocity (typically 5 ft/sec) and differential pressure (30 psi
recommended) are critical components of a correct CIP setup. For additional support, please
contact the Engineering Department at Ampco Pumps Company (414-643-1852).

Ampco Pumps Company
2045 W. Mill Road
Glendale, WI 53209
Phone: [phone] or [phone]
Fax: [phone]
Email: [e-mail]
For additional information on the ZP3 series and other Ampco Pumps products, please visit our
website: www.ampcopumps.com
Revision Date: November 2011