What are three names typically ascribed to the check-valve in diaphragm pumps?

The three names typically associated with the check valve in diaphragm pumps are indeed Duck-Bill, Flapper, and Joker.

These terms describe specific designs and functions of check valves utilized within diaphragm pumps. A Duck-Bill check valve features a flexible, rubber construction shaped like a duck's bill, which opens to allow flow in one direction and closes to prevent backflow. The Flapper valve, likewise, uses a hinged flap that operates similarly to prevent reverse flow while allowing fluid to pass in the intended direction. The Joker valve combines elements of both designs, often utilizing a flexible material and a specific geometry to effectively control flow in one direction while sealing against backflow.

Understanding these specific terminologies is critical for anyone working with diaphragm pumps, as each design can impact performance, maintenance, and applications within various fluid systems. The other options do not relate directly to check valves employed in diaphragm pumps, making them less relevant in this context.