by Lane » Mon Aug 12, 2013 3:37 pm
With such a large vacuum chamber you probably want a vacuum reservoir as well. This can bee something as simple as a pipe with the ends capped and a pipe nipple to get air in/ out. My chamber is a 1/4" steel pipe 10" dia and 20" tall. It has a divider at the mid point, a cap on one end and a piece of plexiglass for a lid, making the chamber and reservoir a single unit. Plumb the system with one 4 way manifold, one T fitting, a pressure gauge and three valves. The T goes to vacuum pump/ inlet valve and the 4 way. The 4 way goes to the gauge, the valves on the chamber and reservoir. To use ( assumes chamber is loaded and lid is on) close the chamber valve and inlet valve, open reservoir valve, start pump and draw vacuum in reservoir, open chamber valve, air will rapidly be drawn from chamber into reservoir and pump, When the rate of change drops (about half the gauge reading) close the reservoir valve so you are not pumping from a large volume, run pump to desired vacuum level and close chamber valve, turn off pump. To release vacuum open the inlet and chamber valves then reservoir valve until gauge reads zero, remove chamber lid.