COMPRESSIBLE FLUID CONTROL SYSTEM VALVE POSITIONER ISOLATION APPARATUS AND METHOD

摘要

Valve positioner isolation apparatus (40) and methods facilitate isolation of one or more compressible fluid control circuits (S, O1, O2, e.g., in pneumatic control systems) from their associated valve positioner (80), so that compressible fluid flow properties therein can be maintained during valve positioner maintenance or replacement. Isolation of the valve positioner (80) from associated control circuits (S, O1, O2) de couples the valve positioner from any associated energization sources. Isolation thereby accomplishes the need to de energize all potential energy sources coupled to the valve positioner without shutting down all ongoing processes associated with the control circuit. Associated lockout features (90, 92, 93) of the present invention, in cooperation with the isolation valve (60, 60', 60"), inhibit unauthorized access and change of the isolation valve operational status.