Baker‑Hughes Masoneilan 4700E/4800E (Electropneumatic) and 4700P/4800P (Pneumatic) are robust, field‑validated valve positioners. Equipped with a high‑precision feedback cam, they deliver precise valve positioning, rapid dynamic response and custom‑tailored control characteristics for control‑valve assemblies. These positioners are fully compatible with both rotary and reciprocating actuators. For rotary‑type actuators, the feedback cam mounts directly onto the actuator shaft. When paired with reciprocating actuators, a simple, heavy‑duty turnbuckle‑and‑lever linkage transfers valve‑stem travel motion to the feedback cam.
Technical Data
- Temperature range
- -54°F to 752°F
- Pressure rating
- Class 150 to 900 (ASME)
Specifications
- One Multi-lobe Cam
- The cam provides field-changeable linear, split-range linear and equal percentage control characteristics. Custom characteristics are available on special order.
- Zero Adjustment
- Adjustment of the positioner zero can easily be accomplished by means of the adjustable spring button. Further zeroing can be performed through the turnbuckle assembly on linear motion actuators.
- Corrosion-resistant Materials
- Premium performance is the standard on the models 4700P/4700E and 4800P/4800E positioners. Internal components are manufactured of corrosion-resistant materials for protection against the harshest environments.
- Fully Enclosed
- All adjustments are fully enclosed for protection from the environment.
- Simplicity
- Positioner action can be reversed without additional parts (4700P/4800P only). The same mounting orientation is used for both direct and reverse action.
- Easy to Maintain
- The pilot valve is the only moving part in the pilot housing. It is easily removed without disassembling any other part of the positioner. An optional bypass valve module is available for use on the model 4700P pneumatic direct acting positioner. Where operating parameters allow, it permits the positioner to be isolated for maintenance while operating the valve directly with the instrument signal. The bypass module is mounted on the back of the positioner to discourage tampering.