Flow Keeps Changing
Problem: The ink flow from my pump keeps increasing and decreasing for no apparent reason.
Possible solutions:
- If the pump is air motor driven the air supplying is failing or being diverted to other equipment. This happens quite often especially if you have several pumps. Usually you can hear the motor speeding up or slowing down but the best way to check the speed using a hand held tachometer.
- Blockages in the discharge line will cause the resistance to increase and reduce the flow. If this blockage gets removed or changes it will cause the flow to return. For instance a dirty filter will change the flow.
- It’s possible the electric motor may be failing causing the motor to speed up and slow down. The best way to check for this is using a hand held tachometer.
- In some very unusual cases if the pump is oversized the immediate rush of flow fills up the chamber or tray which then causes extra resistance which causes the flow to decrease. Then the chamber empties thereby reducing the resistance and allowing the pump to increase flow. The whole process then gets repeated. The best fix for this is to control the flow output close to the pump using a discharge valve or bypass system.
Note: nearly all fluctuating flow problems are caused by speed changes in the motor. |
