Air Operated Double Diaphragm Pump Troubleshooting

What are the main reasons for the malfunction of an Air Operated Diaphragm Pump?

To ensure safe operation and the life of the pump and to form part of a preventative maintenance schedule, routine and complete inspection of the pump is recommended. Routine Inspection can be done by frequent observation of the pump operation is required to detect problems.

A change in sound of the running of the pump can be an indication of wearing parts as well as leakages and changes in performance. The intervals for a complete inspection depend upon the operation conditions of the pump. The characteristics of the liquid, temperature, materials used in the pump and running time decide how often a complete inspection is necessary. Nevertheless, Tapflo recommend to inspect the pump at least once a year.

As part of this inspection, Air and Liquid Kits should be changed and Valve Kits should be changed once every 2 years. Tapflo recommend stocking at least a Liquid and Air Kit to ensure that expensive down time is avoided.

PROBLEMPOSSIBLE FAULTPOSSIBLE SOLUTION
The pump does not runThe air pressure is to lowIncrease air pressure via a filter-regulator
The air connection is blockedCheck / clean air supply connection
Muffler is blockedCheck / clean / replace muffler
Air valve is defectiveClean / replace complete air valve
Dirt in the pump chamberRemove debris from the chambers
Diaphragm breakdownReplace diaphragm
The suction is badSuction connection is not tightTighten the suction line
Suction connection is blockedClean suction line
Muffler is blockedCheck / clean / replace muffler
Valve balls are blocked or damagedCheck dimensions and shape of valve balls
Valve seats are worn Pump starts with high pressure Air in suction / discharge line Dry suction against discharge pressureCheck dimensions and shape of valve seats Start the pump slowly (see chapter 2.2 of manual) Vent suction / discharge line Wet the pump / start without discharge pressure
The pump runs irregularlyValve balls are blockedCheck dimensions and shape of valve balls
Sealing in centre block Air valve is defectiveReplace sealing Clean / replace air valve
Diaphragm breakdown Valve seats are worn Icing on the mufflerReplace diaphragm Check dimensions and shape of valve seats Improve air quality (see chapters 1.7.1 and 2.2.2 of manual)
Bad flow / pressurePressure fall in air supply Pressure losses on suction side Air supply / air valve leakingIncrease air pressure via a filter-regulator Check/change installation on suction side Check / repair / replace air supply / air valve
Suction or air connection blockedCheck / clean air supply / suction connection
Muffler is blockedCheck / clean / replace muffler
Valve ball worn or broken Valve seats are wornCheck dimensions and shape of valve balls Check dimensions and shape of valve seats
Air in liquidSeal suction line; check / refill container
Diaphragm breakdown Icing on the mufflerCheck / replace diaphragms Improve air quality (see chapters 1.7.1 and 2.2.2 of manual)
Liquid leaks from the pumpScrews on the housing not properly tightened O-rings on manifolds damaged Damaged diaphragm Tension / stress form the installationCheck tightening torques of the screws Replace O-rings Check / replace diaphragms Adjust installation, eliminate stress, when using a dampener provide separate support for it (see dampener IOM manual).
Liquid comes out of the mufflerDiaphragm breakdownReplace diaphragm
Diaphragm breakdownWrong selection of material Too high pressure in the installation Long periods of dry running Too high pressure on suction sideContact us for information on material selection Use air treatment system for protection When dry, run pump slowly (see chapter 2.2 of manual) Make sure there is pressure balance between the air and liquid side of the diaphragm
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