Automatic Drain Valves
Model 620-3
For Air Compressor Tanks
The Model 620-3 automatically removes the condensates that collect in the tank, thereby extending the life of the air receiver and downstream air equipment. It is designed for use on all compressors with an unloader port.

Complete drainage is assured by double action of the valve, which opens when the compressor starts and stops.

Long, trouble-free service is provided through simplicity of design and the use of rust-resisting materials. A minimum pressure of 30 PSI is required to permit this valve to function properly. Maximum operating pressure 300 PSI. Use of Fig. 504 recommended on air compressors with 5 horsepower or less.

Temp. range -40°F to 225°F.

Graph K

Model 620-3

Installation Instructions
(see above and Graph K)

INSTRUCTIONS FOR INSTALLATION

It is recommended that the tank drain be opened to below off exiting water, oil and scale before the Automatic Drain Value is installed.

1. Connect 3/8" drain valve inlet (1) to the manual drain valve on the bottom of the tank. Use pipe fitting to adapt. (illustration "C")
2. The 1/8" pilot port (2) must be connected to a point on the compressor package which will provide a pressure/no pressure cycle.
Options: Compressor discharge line between the compressor head and the check valve; check valve bleeder port; Unloader control line (illustration "B"); 3-Way valve on the pressure switch; Suction valve unloader line. (see diagrams on reverse side.)
3. The water and oil is expelled through the 1/4" side outlet port, (3). Some local regulations require filtration of the effluent prior to disposal. We recommend the use of 3/8" copper tubing to carry the effluent to a collection point. Maximum length, 10'.
4. Additional steps may be necessary when applied to air compressors smaller than 5 HP starting with 0 pressure in the tank. Please contact factory for details.

NOTE: State of Calif. code requires a manual "bypass" drain valve be installed in conjuction with automatic drain valves. The kingston Fig. 504 can satisfy this requirement. Re: Title 8, Section 465(a) unfired pressure vessel safety orders.