T7800 Electro Pneumatic Transducer
The T7800 is an electro-pneumatic I/P and E/P transducer that converts a DC input signal to a linear proportional pneumatic...
What This Model Does
The T7800 is an electro-pneumatic I/P and E/P transducer that converts a DC input signal to a linear proportional pneumatic output. Built around a solid-state controlled piezoelectric ceramic actuator and internal electronic feedback, it maintains precise output pressure regardless of vibration or mounting position. A pneumatic relay section with upper and lower control diaphragms isolates signal conversion from supply air fluctuations. It is a form, fit, and function alternative to Fairchild T7800 series transducers, supplied for replacement in process plants and integration into OEM instrumentation systems.
| Model | T7800 Series |
|---|---|
| Type | Electro-pneumatic I/P, E/P transducer |
| Conversion principle | Piezoelectric ceramic actuator flapper with pneumatic relay |
| Input signal | DC input signal |
| Output action | Linear proportional pneumatic output, field reversible |
| Feedback type | Internal electronic feedback |
| Enclosure rating | IP65, NEMA 4X, Type 4 |
| Interference protection | RFI/EMI protection |
| Certification | Canadian Registration Numbers (CRN) all territories and provinces |
| Warranty | 18 months |
Why Buyers Specify This Model
- Piezoelectric ceramic actuator controls output pressure accurately regardless of plant vibration or mounting angle
- Internal electronic feedback loop continuously corrects output pressure back to target signal levels
- Field reversible function delivers an inversely proportional pneumatic output when control logic requires it
- Built-in RFI and EMI protection eliminates signal drift caused by radio and electromagnetic interference
- Damping adjustment allows loop tuning to eliminate overshoot and match specific process dynamics
- Split range operation allows one common DC control signal to drive two or more pneumatic functions
- Compact enclosure fits restricted control valve yokes, skid packages, and crowded instrument panels
- Enclosure rated IP65, NEMA 4X, and Type 4 for reliable indoor and outdoor plant installation
Problems It Solves
- Output pressure shifts when orientation changes or when pipe vibration shakes the transducer body
- Radio frequency and electromagnetic interference from nearby drives or radios corrupts control signals
- Original equipment manufacturer lead times cause extended downtime during plant maintenance turnarounds
- Loop hunting or slow response caused by inability to tune transducer damping to actuator volume
- Need to run direct and reverse acting pneumatic outputs from identical DC controller hardware
Application Scenarios
- Process control valves where continuous plant vibration causes drift in standard voice-coil transducers
- Offshore or outdoor skid packages requiring IP65 and NEMA 4X environmental protection against weather
- Split-range control loops where a single DC controller output sequences two separate control valves
- High-interference electrical substations or motor control rooms requiring robust RFI and EMI protection
- Direct replacement of worn Fairchild T7800 series units on existing valve brackets without repiping
- Tight instrument enclosures and valve manifolds where compact transducer dimensions are required
Who It Is For
- Plant instrumentation technicians replacing obsolete or failing T7800 series I/P transducers
- Control valve and actuator OEMs sourcing drop-in I/P converters under their own brand
- EPC contractors specifying field-reversible electro-pneumatic converters for process automation skids
- Instrumentation distributors maintaining local stock of direct replacement transducers for process facilities
- Engineering trading firms supplying fast-shipment pneumatic control spares to industrial plants
Technical Features
- Primary converting section uses a solid-state piezoelectric ceramic actuator functioning as a flapper
- Nozzle and flapper arrangement modulates signal pressure feeding the pneumatic relay section
- Upper control diaphragm receives signal pressure to set final transducer output pressure
- Lower control diaphragm in the pneumatic relay section continuously senses actual output pressure
- Internal electronic feedback ensures precise output pressure regardless of vibration or mounting position
- Built-in damping adjustment for smooth tuning and dynamic response control
- Field reversible feature enables inverse output action relative to DC input signal
- Certified under Canadian Registration Numbers CRN across all Canadian territories and provinces
Materials and Construction
- Piezoelectric ceramic actuator element
- Control diaphragms in pneumatic relay section
- Full material and finish breakdown is given in the datasheet PDF
Dimensions and Connection Detail
Reference image published with this model on the original catalogue. Confirm critical dimensions against the datasheet before machining a bracket.
Manufacturing and Quality Control
Every unit is calibrated and stroke tested before it is packed. We can film or photograph your units in the sample room or warehouse before they ship.
Manufacturing Steps
Machining and finishing of transducer enclosure and pneumatic relay body
Assembly of piezoelectric ceramic flapper and nozzle primary conversion section
Integration of internal electronic feedback circuitry with RFI and EMI shielding
Pneumatic relay and diaphragm assembly
Calibration of direct and reverse output ranges on precision air test bench
Damping adjustment verification and signal conversion testing
Customer custom colour coating and brand nameplate marking when ordered
Packaging into standard or customised cartons for dispatch
Quality Control
- Every unit undergoes operational pressure and signal response testing prior to shipment
- Sample room or warehouse photos and video of actual order available upon request
- Defective units under 18-month warranty replaced based on photo or video evidence rather than repaired
- Emergency replacement goods dispatched promptly when client operations are halted
Customisation Options
- Customer logo and custom brand marking on product nameplate
- Housing painted in black, blue, yellow, or custom specified colours
- Custom-designed shape modules manufactured to customer technical drawings
- Outer carton and inner retail or protective packaging tailored to customer specifications
How It Compares With the Alternatives
| Voice coil I/P transducers | Piezoelectric actuators eliminate mechanical coil mass, preventing output shift under severe vibration |
|---|---|
| Non-feedback pneumatic transducers | Internal electronic feedback actively monitors and corrects output pressure rather than relying on open-loop balance |
| Standard commercial converters | IP65 and NEMA 4X Type 4 housing ensures outdoor environmental sealing without secondary enclosures |
Fitting and Setting Up This Model
General field procedure. Always follow the datasheet for the exact calibration sequence and any hazardous area requirements.
Mount transducer securely using chosen bracket orientation, as piezoelectric design allows arbitrary mounting position
Supply clean, dry instrument-grade compressed air to the designated pneumatic inlet connection
Connect electrical DC input signal wires to terminal block, verifying polarity for direct operation
Select field reverse setting if application calls for output pressure inversely proportional to input
Adjust internal damping potentiometer to stabilise pneumatic output against actuator volume and line resistance
Calibrate span and zero settings against external reference gauge until desired pneumatic range is achieved
Periodically inspect upstream air supply filtration to prevent moisture and oil contamination at the nozzle
T7800 Electro Pneumatic Transducer FAQ
What is the standard lead time for the T7800 transducer?
Standard quantities normally dispatch within 2 to 3 days from inventory, while large orders require 7 to 10 days.
Can this unit directly replace an existing Fairchild T7800 series unit?
Yes, it is designed as a form, fit, and function replacement with matching mounting, pneumatic ports, and electrical signals.
Does mounting orientation affect output pressure calibration?
No, the solid-state piezoelectric ceramic actuator and internal electronic feedback prevent output drift across different mounting angles.
Can the pneumatic output action be reversed in the field?
Yes, the transducer includes a built-in field reversible feature to provide an output inversely proportional to the input.
What warranty is provided for industrial installations?
All units carry an 18-month warranty, with faulty units replaced upon review of photo or video evidence.
Can we purchase these transducers with our own company branding?
Yes, we provide OEM branding including custom nameplates, customer logo printing, and housing paint in your chosen colour.
Applications Cases and Guides
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