Inventors:
Christopher G. Thackeray - Etna CA
Preston C. Rosenbaum - Butte Falls OR
Tim E. Nilsson - Yreka CA
Assignee:
Nor-Cal Products, Inc. - Yreka CA
International Classification:
F16K 154
Abstract:
A valve 10 is provided which has two pathways which each extend between an inlet bore 4 and an outlet bore 6 of the valve 10. A soft start passage 55 initially opens to equalize pressure between the inlet bore 4 and the outlet bore 6. A main poppet or other barrier 50 then opens to provide direct communication of large volumes of gas between the inlet bore 4 and the outlet bore 6. A pneumatic cylinder 20 has a single piston 30 therein which is moved downward to actuate a soft start shaft 40 and associated soft start poppet 45 to open the soft start passage 55. When air is directed into a lower air chamber 28 below the piston 30, the piston 30 is caused to be elevated within the pneumatic cylinder 20 and the entire soft start shaft 40 and main poppet 50 assembly moves up to provide direct access of larger volumes of gas between the inlet bore 4 and the outlet bore 6. A soft start return spring 42 and main spring 58 bias the piston 30 toward a central position within the pneumatic cylinder 20 with the soft start poppet 45 and main poppet 50 both in closed positions.