5
1.5 Control Assembly
Figure 5
PULSAR Shadow® pumps incorporate a lost motion style of stroke length adjustment to limit
diaphragm travel during the suction portion of each stroke. The stroke length setting is indicated by a (0
- 100) scale located on the top of the unit.
Stroke length is changed by depressing and turning the hand knob. This turns a screw, which locates a
wedge-shaped slider cam to position the follower pin, which in turn limits rearward travel of the
diaphragm.
To increase stroke length, the slider cam is moved downwards. This allows the follower pin to slide
back, increasing the distance the diaphragm can travel with each pump stroke.
To decrease stroke length, the slider cam is moved upwards. This moves the follower pin forwards,
decreasing the diaphragm travel, and therefore the flow rate of the pump.
