66610X-X-C (en)
Page 3 of 8
GENERAL DESCRIPTION
The ARO diaphragm pump offers high volume delivery even
at low air pressure and a broad range of material compati-
bility options available. Refer to the model and option chart.
ARO pumps feature stall resistant design, modular air motor /
fluid sections. Air operated double diaphragm pumps utilize
a pressure differential in the air chambers to alternately cre-
ate suction and positive fluid pressure in the fluid chambers,
valve checks ensure a positive flow of fluid. Pump cycling will
begin as air pressure is applied and it will continue to pump
and keep up with the demand. It will build and maintain line
pressure and will stop cycling once maximum line pressure is
reached (dispensing device closed) and will resume pumping
as needed.
AIR AND LUBE REQUIREMENTS
WARNING
EXCESSIVE AIR PRESSURE. Can cause
personal
injury, pump damage or property damage.
y
A filter capable of filtering out particles larger than 50 mi-
crons should be used on the air supply. There is no lubrication
required other than the “O” ring lubricant which is applied
during assembly or repair.
y
If lubricated air is present, make sure that it is compatible
with the “O” rings and seals in the air motor section of the
pump.
OPERATING INSTRUCTIONS
y
Always flush the pump with a solvent compatible with
the material being pumped if the material being pumped
is subject to “setting up” when not in use for a period of
time.
y
Disconnect the air supply from the pump if it is to be in-
active for a few hours.
y
The outlet material volume is governed not only by the
air supply, but also by the material supply available at the
inlet. The material supply tubing should not be too small
or restrictive. Be sure not to use hose which might co
lapse.
y
When the diaphragm pump is used in a forced-feed
(flooded inlet) situation, it is recommended that a “Check
Valve” be installed at the air inlet.
y
Secure the diaphragm pump legs to a suitable surface to
ensure against damage by vibration.
MAINTENANCE
Refer to the part views and descriptions as provided on pages
4 through 7 for parts identification and service kit information.
y
Certain ARO “Smart Parts” are indicated which should be
available for fast repair and reduction of down time.
y
Service kits are divided to service two separate dia-
phragm pump functions: 1. AIR SECTION, 2. FLUID SEC-
TION. The FLUID SECTION is divided further to match
typical part MATERIAL OPTIONS.
y
Provide a clean work surface to protect sensitive internal
moving parts from contamination from dirt and foreign
matter during service disassembly and reassembly.
y
Keep good records of service activity and include pump
in preventive maintenance program.
y
Before disassembling, empty captured material in the
outlet manifold by turning the pump upside down to
drain material from the pump.
FLUID SECTION DISASSEMBLY
1. Remove top manifold(s).
2. Remove (22) balls, (19) “O” rings and (21) seats.
3. Remove (15) fluid caps.
NOTE:
Only PTFE diaphragm models use a primary dia-
phragm (7) and a backup diaphragm (8). Refer to the auxilia-
ry view in the Fluid Section
Illustration.
For 6661XX-XX6-C:
4. Remove (7) diaphragm, (5) washers and (30) shims.
For other models:
4. Remove the (14) screws, (6) washers, (7) or (7 / 8) dia-
phragms and (5) washers.
5. Remove (3) “O” rings.
Viton
®
and Hytrel
®
are registered trademarks of the DuPont
®
Company. Kynar
®
is a registered trademark of Penwell Corp
Santoprene
®
is a registered trademark of Monsanto Company, licensed to Advanced Elastomer Systems, L.P. Key-Lube
®
is a registered trademark of Key Industries
FLUID SECTION REASSEMBLY
y
Reassemble in reverse order.
y
Clean and inspect all parts. Replace worn or damaged
parts with new parts as required.
y
Lubricate (1) diaphragm rod and (2) “O” ring with Key-
Lube “O” ring lube.
y
Use ARO pn / 98931-T bullet (installation tool) to aid in
installation of (2) “O” ring on (1) diaphragm rod.
For 6661XX-XX6-C:
y
Attach a regulated airline to the pump inlet; gradually
increasing the air pressure (6-8 psi) to check which side of
the pump with air blowing out, and then shut down the
air supplier.
y
Fasten (7) diaphragm with (5) washer into (1) diaphragm
rod, and insert them into (101) Center body from the
chamber identified with blowing air in the previous step.
y
Install (15) fluid cap.
y
Thread the other side of (7) diaphragm with (5) washer
into (1) diaphragm rod, but do not tighten it.
y
Record the angle for the misalignment between (7) dia-
phragm hole and (101) center body holes, then unthread
the (7) diaphragm and place proper Qty. of (30) shims
between (5) washer and (1) diaphragm rod.
y
Attach a regulated airline to the pump inlet, gradually
increasing the air pressure (6-8 psi) until the diaphragm
shift to the other site, shut down the air supply.
y
Install the second (15) fluid cap.
NOTE:
For details, refer to service kits manual 48495949.
For other models:
y
Be certain (7) or (7 / 8) diaphragm(s) align properly with
(15) fluid caps before making final torque adjustments on
bolt and nuts to avoid twisting the diaphragm.
y
For models with PTFE diaphragms: Item (8) Santoprene
diaphragm is installed with the side marked “AIR SIDE” to-
wards the pump center body. Install the PTFE diaphragm
with the side marked “FLUID SIDE” towards the fluid cap.
y
Re-check torque settings after pump has been re-started
and run a while.
