Fisher™ 2500?249 Pneumatic Controllers and
Transmitters
This bulletin contains dimensional information for
Fisher displacer?type sensors and for controllers and
transmitters used with these sensors. Dimensions are
subject to change and certified dimensions should be
requested for construction projects. Some of the
abbreviations used in this document are as follows:
NPT = National Pipe Thread, NPS = Nominal Pipe Size,
FF = Flat Face Flange, RF = Raised Face Flange, and
RTJ = Ring Type Joint Flange.
Flange specification references are ASME B16.1 for
CL125 and 250 and ASME 16.5 for CL150, 300, 600,
900, 1500 and 2500.
FeaturesSet point, proportional valve opening, and reset changes are made with simple dial knob controls.Few moving parts are used. A knife-edged driver bearing in the sensor and the plated brass instrument case ball bearing for the torque tube rotary shaft help to provide low-friction operation.Available in a variety of orientations and connection styles, and all sensors can be either right- or left-hand mounted.Displacer reaction to small specific gravity changes allows these instruments to be used for level, interface of two fluids, and density applications where a response to low levels of input signal change is required.Action is field reversible from direct to reverse or vice versa, without additional parts.Supply pressure conservation is enhanced in all constructions because relay exhaust opens only when input signal changes.Comes standard with a liquid damping orifice in the lower equalizing connection for the cage sensor that helps provide additional stability.
