I'm looking for a miniature (has to fit into an enclosure of size 90x35x15mm or 3.54x1.38x0.59in) vacuum pump that should generate a vacuum of 200mBar.

Shutdown Valve (SDV) are used for isolation of process system in case of emergency. i) Should a preventive measure (PM) apply on SDV ?

I know selecting the valve material for a specific application is not easy but are there any literature that I can work on?

How do I make a closed cell foam (rigid) to use as a float to operate a level control valve (diesel fuel)