The 4" pneumatic valves can be used to intercept hydrocarbons such as diesel, gasoline, kerosene, airplane fuel products and various solvents with the exception of special versions requested by clients for the specific use.
In standby (no low flow and high flow air supply) the shutter, attached to the shaft, presses on gasket thanks to the action of a spring preventing the “IN”-“OUT” passage. Once closed, the action of the spring is reinforced by the force due to the differential section defined by the construction diameters of the shutter and its inner guide which contributes to the “seal” of the valve.
The valve can have the following operating states:
  • Full flow opening: By supplying the high flow and low flow fitting, the piston, attached to the shaft lifts the shutter until the piston mechanically comes into contact with head while another piston lifts until coming into contact with the head on top of the valve. Full flow is created in this condition.
  • Reduced flow opening: By supplying the low flow fitting the piston lifts until it comes into contact with the top lifting the shutter as well by a measurement which depends on the relative distance between the piston and the stop nut. In the two movements the spring is further compressed which brings the valve into the closing position, when the supply pressure is intentionally shut of (or fails).
  • Change from full flow to reduced flow: The supply is shut off to the high flow fitting so that the spring lowers shutter and everything attached to it. Since the supply is not disconnected from the low flow fitting, the descent is stopped when the nut comes into contact with the piston.
  • Change from full flow to zero flow: The supply is shut off simultaneously to the high flow and low flow fittings.
  • Change from reduced flow to zero flow: The supply is shut off to the low flow fitting.
  • Body, cover, shutter and guide (main pressurized parts and in contact with the fluid to intercept): aluminium
  • Drive parts (cylinders, pistons, heads): aluminium
  • Shafts: stainless steel AISI 316
  • Springs: stainless steel AISI 302
  • Gaskets: Viton, Teflon
  • Screws: carbon steel, stainless steel
  • Flow Rate: 1700 LPM