User Manual

Blagdon Pump • A Unit of IDEX Corporation • R79 Shannon Industrial Estate • Co Clare, Ireland • Tel: [phone] • Fax: [phone]
www.blagdonpump.com • E-Mail: [e-mail]
x75mdl1sm-rev0812
Page 8
Air Operated Double Diaphragm Pump 6/05 Page 8
TROUBLESHOOTING
Possible Symptoms:
• Pump will not cycle.
• Pump cycles, but produces no flow.
• Pump cycles, but flow rate is
unsatisfactory.
• Pump cycle seems unbalanced.
• Pump cycle seems to produce
excessive vibration.
What to Check: Excessive suction lift
in system.
Corrective Action: For lifts exceeding
20 feet (6 meters), filling the pumping
chambers with liquid will prime the pump
in most cases.
What to Check: Excessive flooded
suction in system.
Corrective Action: For flooded
conditions exceeding 10 feet (3 meters)
of liquid, install a back pressure device.
What to Check: System head exceeds
air supply pressure.
Corrective Action: Increase the inlet air
pressure to the pump. Most diaphragm
pumps are designed for 1:1 pressure
ratio at zero flow.
What to Check: Air supply pressure or
volume exceeds system head.
Corrective Action: Decrease inlet air
pressure and volume to the pump as
calculated on the published
PERFORMANCE CURVE. Pump is
cavitating the fluid by fast cycling.
What to Check: Undersized suction line.
Corrective Action: Meet or exceed
pump connection recommendations
shown on the DIMENSIONAL
DRAWING.
What to Check: Restricted or undersized
air line.
Corrective Action: Install a larger air line
and connection. Refer to air inlet
recommendations shown in your pump’s
SERVICE MANUAL.
What to Check: Check ESADS, the
Externally Serviceable Air Distribution
System of the pump.
Corrective Action: Disassemble and
inspect the main air distribution valve,
pilot valve and pilot valve actuators.
Refer to the parts drawing and air valve
section of the SERVICE MANUAL.
Check for clogged discharge or closed
valve before reassembly.
What to Check: Rigid pipe connections
to pump.
Corrective Action: Install flexible
connectors and a surge suppressor.
What to Check: Blocked air exhaust
muffler.
Corrective Action: Remove muffler
screen, clean or de-ice and reinstall.
Refer to the Air Exhaust section of your
pump SERVICE MANUAL.
What to Check: Pumped fluid in air
exhaust muffler.
Corrective Action: Disassemble pump
chambers. Inspect for diaphragm rupture
or loose diaphragm plate assembly. Refer
to the Diaphragm Replacement section
of your pump SERVICE MANUAL.
What to Check: Suction side air leakage
or air in product.
Corrective Action: Visually inspect all
suction side gaskets and pipe
connections.
What to Check: Obstructed check
valve.
Corrective Action: Disassemble the wet
end of the pump and manually dislodge
obstruction in the check valve pocket.
Refer to the Check Valve section of the
pump SERVICE MANUAL for
disassembly instructions.
What to Check: Worn or misaligned
check valve or check valve seat.
Corrective Action: Inspect check valves
and seats for wear and proper seating.
Replace if necessary. Refer to Check
Valve section of the pump SERVICE
MANUAL for disassembly instructions.
What to Check: Blocked suction line.
Corrective Action: Remove or flush
obstruction. Check and clear all suction
screens and strainers.
What to Check: Blocked discharge line.
Corrective Action: Check for obstruction
or closed discharge line valves.
What to Check: Blocked pumping
chamber.
Corrective Action: Disassemble and
inspect the wetted chambers of the
pump. Remove or flush any obstructions.
Refer to the pump SERVICE MANUAL
for disassembly instructions.
What to Check: Entrained air or vapor
lock in one or both pumping chambers.
Corrective Action: Purge chambers
through tapped chamber vent plugs.
PURGING THE CHAMBERS OF AIR
CAN BE DANGEROUS! Contact the
Technical Services Group before
performing this procedure. Any model
with top-ported discharge will reduce or
eliminate problems with entrained air.
If your pump continues to perform
below your expectations, contact your
local Distributor or factory Technical
Services Group for a service evaluation.
WARRANTY
Refer to the enclosed Warranty
Certificate.