Shellab SVAC2E-2 - Manual (Page 9)

9
VACUUM OPERATION
6.1 A pump with a pumping capacity four times greater than the chamber volume is
advisable. The SVAC1E (1407) & SVAC1E-2 (1407-2) have a chamber volume of .6
cubic feet, so a pump with a pumping capacity of 4 cubic feet per minute is
recommended. When working below 1mm, a diffusion type pump will be needed. The
SVAC2E (1408) & SVAC2E-2 (1408-2) have a chamber volume of 1.5 cubic feet so a
pump with a capacity of 6 cubic feet per minute is recommended.
6.2 IT IS IMPORTANT TO USE VACUUM TUBING FOR ALL THE VACUUM HOOKUPS.
OTHER TYPES OF TUBING MAY COLLAPSE AND PREVENT COMPLETE
EVACUATION.
6.3 To Apply Vacuum to the Chamber: Attach the hose from the vacuum pump to the 3/8”
tube marked “Vacuum” on the rear of the unit. Close the vent valve on the control panel.
Open the vacuum valve on the control panel. Latch the door shut and start the vacuum
pump. This action will hold the door shut and against the gasket until the pump creates a
vacuum in the chamber. Once a good vacuum seal is accomplished, the door will hold
itself shut and sealed until the chamber is returned to atmospheric pressure.
6.4 Watch the VACUUM GAUGE and when the required vacuum is obtained, close the
vacuum valve and then turn the pump off. The VACUUM GAUGE is incremented from 0
to 30 inches of Hg (76 cm of Hg) with zero representing atmospheric pressure.
6.5 Vacuum Relief: To return the chamber to atmospheric pressure, open the vent valve
very slowly (the one not connected to the vacuum), and allow the chamber to return to
atmospheric pressure. The speed at which the vacuum is relieved can be controlled by
how much the valve is opened.
Section
6