US 5,439,021 A · Electro-pneumatic converter

Abstract

An electro-pneumatic converter device with modular components and with supporting housing structure enabling the device to be readily convertible from a current to pressure positioner to a current to pressure transducer. A valve positioner with an enclosure having a housing, a modular base, and a separable field terminal box. A self contained cover mounted to the enclosure with no additional mounting components. A plastic pneumatic relay ultrasonically welded together to eliminate metal mounting parts and lower assembly time. Open channels in a housing surface cooperating with a gasket to provide fluid passageways between the housing and the modular base. Pressure gauges are removably mounted on a modular unit for location completely within the housing. A floating interconnect terminal board permits self-aligning of mating terminals as the modular unit is inserted into the housing. A supply biased pneumatic pressure relay has supply pressure channeled to the supply port and also to a supply bias cavity through a capillary hole.

Claims16

Dependent claims

An electro-pneumatic convertible instrument readily convertible from a pressure transducer to a valve positioner for indicating the position of a valve using a feedback element having a shaft connectable to a valve stem where the feedback element output corresponds to the valve stem position, said instrument comprising:

an enclosure having a housing defining a hollow interior and including;
a modular base having a dividing wall and with electrical and pneumatic components mounted thereon on opposite sides of said dividing wall, said modular base removably insertable into said housing and defining respective electrical and pneumatic compartments within said housing on opposite sides of said dividing wall for segregating said electrical and pneumatic components therein;
and
said housing including a housing portion adapted for receiving and mounting therein said feedback element and shaft in converting the instrument to a valve positioner, said housing portion having one end thereof opening directly into the housing hollow interior for communicating with said hollow interior to enable said feedback element output to be connectable to said electrical components on said modular base and within said electrical compartment via said housing portion and said hollow interior.

1 more element

Dependencies are inferred from the claim text.

Electro-pneumatic converter

Life of this patent

Electro-pneumatic converter

Life of this patent

Abstract

Claims16