The Suntec E1001 Series pumps are designed for use with light or medium oil. They are suitable for use with a one or two pipe system and are usually used with an in-line solenoid valve.
During starting period when the gear-set speed is increasing, all the oil passes through a special flat on the piston, back to the return. Once the speed reaches a certain value and the flow can no longer pass through this flat, then the pressure increases rapidly overcoming the valve spring force and opens the valve. During the stop sequence, the gear-set speed slows down and the valve closes when the gear-set capacity is lower than the flat flow.
The cut-on and cut-off speeds depend on the gear-set size and set pressure.
Rotation of these pumps is determined by viewing the pump from the shaft end.