Patent ID: 8378249

Claim:
A plasma cutting system comprising: a plasma torch actuated by a trigger and connected to a power source; a gas supply system constructed to provide a pressurized source of gas to the plasma torch; and a proportional valve configured to regulate the pressurized gas, the proportional valve comprising: a body; a valve seat positioned within the body and defining a valve orifice; a plunger having a mating surface on one end and a pressure receiving surface on an opposite end, the mating surface configured to mate with the valve seat and the orifice; at least one inlet connected to receive the pressurized source of gas on one end and to distribute the pressurized gas to the valve orifice and the pressure receiving surface of the plunger; an electrical solenoid mounted in the body and having a chamber to electro-magnetically translate the plunger therein; a bias urging the plunger toward the valve orifice in conjunction with the pressurized gas when electrical power is reduced to the electrical solenoid; and a pressure switch positioned upstream from the valve orifice, the pressure switch including a tactile dome switch configured to actuate at a pre-determined inlet gas pressure.