Vent assembly and method for a digital valve positioner

A digital valve positioner for use with an actuator, the digital valve positioner comprising:

• a housing;
• at least one exhaust port opening formed in the housing;
• a vent assembly operatively coupled to the at least one exhaust port opening, the vent assembly including:
• a body operatively coupled to the at least one exhaust port opening, the body including a bore;
• a valve seat surrounding the bore;
• and
• a check valve disposed within the bore, the check valve arranged to shift from a closed position seated against the valve seat to an open position disposed away from the valve seat when an exhaust medium flows through the at least one exhaust port opening;
• and
• a cap removably secured to the body, the cap having a plurality of barriers extending therefrom and disposed around the check valve to enclose the check valve, the cap and the plurality of barriers arranged to prevent an external medium from entering the check valve and to provide a tortuous flow path for the exhaust medium reducing sound through the vent assembly.

A vent assembly for a digital valve positioner operatively coupled to an actuator, the vent assembly comprising:

• a body having an inlet, an outlet, a bore disposed between the inlet and the outlet, a plurality of apertures surrounding the bore, a valve seat surrounding the plurality of apertures, the body adapted to be operatively secured to an exhaust port opening of the digital valve positioner;
• an umbrella valve disposed within the bore, the umbrella valve biased in a closed position, such that the umbrella valve is shiftable between the closed position seated against the valve seat and an open position disposed away from the valve seat when an exhaust medium flows through the inlet of the body;
• and
• an enclosure disposed around the umbrella valve and positioned to enclose the umbrella valve, the enclosure comprising a plurality of barriers arranged to prevent an external medium from entering the umbrella valve and to provide a tortuous flow path for the exhaust medium reducing sound through the vent assembly without affecting flow capacity.

A method of venting a digital valve positioner operatively coupled to an actuator, the digital valve positioner comprising a housing and at least one exhaust port opening formed in the housing, the method comprising:

• providing a vent assembly comprising a check valve surrounded by a plurality of barriers;
• operatively securing the vent assembly to the at least one exhaust port opening;
• directing an exhaust medium into the check valve and through the plurality of barriers, reducing the sound of the exhaust medium flowing through the vent assembly;
• and
• preventing an external medium from entering the check valve without affecting the flow capacity of the digital valve positioner.