•To select no gas ballast flow (not recommended), turn the restrictor plate so that none of the indentations are aligned with the indentation on the side of the oil return assembly.
•To select low gas ballast flow, turn the restrictor plate so that the single indentation on the restrictor plate is aligned with the indentation on the side of the oil return assembly.
•To select high gas ballast flow (the setting the ballast control is shipped from the factory), turn the restrictor plate so that the two indentations are aligned with the indentation on the side of the oil return assembly.
Installing the Welch Dry Piston Vacuum Pump
The Welch Dry Piston Pump may be used as a direct replacement for an
To install the dry piston vacuum pump, follow these steps:
1Remove the pump from its packaging and place on an accessible work surface with the power cord side nearest to you and the pump "INLET" port to your right. Refer to Figure 15 as a visual aid to these instructions.
2Verify that the voltage of the pump matches that of the Detector.
3Open the plastic bag containing the Dry Piston Pump Kit. Locate the brass elbow and brass barb (3/8" NPT). Remove their plastic protective caps and wrap three or four turns of Teflon tape (not supplied) onto the threaded connections. Screw the barb fitting into the elbow and tighten using wrenches. Similarly, remove the plastic cap from the pump's inlet fitting and screw elbow into it. Tighten the elbow so that the barb ends up pointed parallel to the floor and pointed toward the power cord side of the pump.
4Locate the mounting brackets, 4 small screws and washers and spring clips. Use 2 screws and washers to attach the spring clips, one to each bracket.
5Using the supplied Torx wrench, remove two Torx screws from the pump, the right corner screw located closest to you and the closest screw to you located immediately to the left of the pump's handle.
6Attach the brackets to these locations using the Torx screws as showing in Figure 15.
7Attach the short piece of ½" ID hose tubing supplied in the Dry Piston Pump Kit to the brass barb and use one of the supplied hose clamps to tighten it onto the barb.
8Place a second hose clamp over the other end of the plastic tube. Insert the barb on the elbow end of a Chemical Trap into the open end of the short plastic hose that was just attached to the brass barb on the pump.
9Rotate the Chemical Trap so that it is retained by the spring clips.
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