The pneumatic diaphragm metering pump consists of a liquid chamber and an air chamber separated by a diaphragm. In the liquid chamber, the suction (inlet) and discharge (outlet) ports have check valves that control the direction of the fluid flow. A pipe nipple connects the controller to the pump air chamber. In the air chamber, the air/gas power supply from the controller enters and exhausts through the pipe nipple connector. When the controller exhausts the air/gas supply, the liquid suction pressure and the return spring force the diaphragm backwards. The diaphragm stops when the end of the diaphragm stem, which is attached to the air chamber side of the diaphragm, collides with the end of the stroke adjuster.
Features
Simple design
Easy to maintain
Intrinsic safety of pneumatic operation
Stroke length and stroke rate adjustment
High-flow turndown
Corrosion resistant construction
All 316 SS or TFE wetted parts
Ease of installation
Recommended for discharge pressures below 120 psi
Design Improvements
Higher flow rates than PD pump models
All PTFE diaphragms for all pump sizes
PTFE-coated o-rings in contact with process fluid
FKM o-rings in contact with air/gas supply
Stroke adjuster scale easier to read and set than previous diaphragm pump models
Check valves for 316SS models have PTFE soft seats with 316SS balls (LD200 & D400)
Check valves for PTFE models have PTFE soft seats with ceramic balls (LD200 & D400)
Check valves on LD100 models are PVDF with PVDF soft seats and ceramic or ruby sapphire balls