Abstract: A system for removing dead volume in a sensor assembly of a mass flow controller is presented. The system comprises a valve assembly communicable coupled to the sensor assembly. The valve assembly is in fluid communication with fluid in a primary flow path and the sensor assembly is in fluid communication with fluid in the primary flow path. The sensor assembly comprises a pressure transducer having a first reservoir and another pressure transducer having a second reservoir. The first reservoir has a port in fluid communication with fluid in a sampled flow path. The second reservoir is coupled to a second pressure transducer and is fluidly coupled to the first reservoir through a flow through path. The second reservoir also includes another port for communicating the flow of fluid from the flow through path to another flow path. A flow rate restrictor is disposed in the flow through path.

Abstract: A valve assembly used to control fluid flow rate. The valve assembly comprises a valve plunger and a shield. The valve plunger forces fluid having a flow rate to flow between an inlet and an outlet in response to an applied actuator force. The actuator force is applied to a first side and the fluid is applied to a second side of the valve plunger. The shield minimizes or eliminates a destabilizing force caused by static pressure, created by fluid interaction on the second side. The shield is either coupled to, formed in, or suspended from underneath the valve plunger and extends a length into the outlet. The valve assembly further comprises an orifice between the inlet and the outlet wherein the orifice comprises at least one planar surface and at least one non-planar surface. The shield shields a section of the second side from the fluid.

Abstract: A valve assembly used to control fluid flow rate. The valve assembly comprises a valve plunger and a shield. The valve plunger forces fluid having a flow rate to flow between an inlet and an outlet in response to an applied actuator force. The actuator force is applied to a first side and the fluid is applied to a second side of the valve plunger. The shield minimizes or eliminates a destabilizing force caused by static pressure, created by fluid interaction on the second side. The shield is either coupled to, formed in, or suspended from underneath the valve plunger and extends a length into the outlet. The valve assembly further comprises an orifice between the inlet and the outlet wherein the orifice comprises at least one planar surface and at least one non-planar surface. The shield shields a section of the second side from the fluid.

Abstract: A valve assembly used to control fluid flow rate. The valve assembly comprises a valve plunger and a shield. The valve plunger forces fluid having a flow rate to flow between an inlet and an outlet in response to an applied actuator force. The actuator force is applied to a first side and the fluid is applied to a second side of the valve plunger. The shield minimizes or eliminates a destabilizing force caused by static pressure, created by fluid interaction on the second side. The shield is either coupled to, formed in, or suspended from underneath the valve plunger and extends a length into the outlet. The valve assembly further comprises an orifice between the inlet and the outlet wherein the orifice comprises at least one planar surface and at least one non-planar surface. The shield shields a section of the second side from the fluid.