Series 73 P/P

Description

The Moore Series 73 Built-in Valve Positioners use the full force of their air supply to drive and maintain the piston or diaphragm in a pneumatic actuator to position a valve to what is required by a control instrument, regardless of the presence of forces that change valve position.

This line of compact instruments incorporates a single-axis, force-balance principle of operation to ensure accurate and stable control valve positioning. In all cases, including bottom-loading applications, a Model 73 Built-In Valve Positioner is mounted directly on the topwork of the valve, with no external levers or other exposed mechanisms.

Each positioner receives a signal from a control instrument, and using an air supply as high as 100 psig, the positioner strokes the valve actuator to the required position. 5

Like all valve positioners, the Model 73 Built-In Valve Positioners have feedback circuits designed to measure the position of the actuator's piston or diaphragm. The positioner then supplies or exhausts air to bring the actuator within the required range for its corresponding control instrument.

The position of the piston or diaphragm in the valve actuator is sensed by the amount of compressive force exerted by a range spring on the valve positioner's diaphragm assembly. By selecting the appropriate range spring from the wide selection available almost any combination of valve stroke (from 1/4" to 4") and instrument span (from 2 to 24 psi) can be obtained.

Features & Benefits

• Single-axis, force-balance principle of operation, ensures accurate and stable positioning.
• Feedback circuits direct the actuator’s position, ensuring adherence to the control instrument signal
• Range spring capability accommodates a wide variety of valve strokes and instrument spans

Specifications

Functional Specifications

Input Range

3-15, 3-9, 9-15, 6-30, 3-27 psig

Valve Travel

Minimum: 1/4"

Maximum: 4"

Supply Pressure

Minimum: 3 psi above required actuator pressure

Maximum: 100 psig

Air Consumption

(In balance condition with 20 psig supply and 9 psig deadended output)

• 73N_F: 0.25 scfm
• 73N_B: 0.6 scfm

Overrange Limit

150 psig to any connection

Response Level

(output sensitivity to input pressure changes)

• 73N_F: 0.1% of input span
• 73N_B: 0.25% of input span

Functional Mechanical

Materials of Construction

Aluminum, brass, stainless steel, Neoprene®, and/or Buna-N