Controllers are control loop feedback mechanisms often found in industrial control systems. These systems consist of a collection of several components joined together to run a larger system. These systems are utilized to operate an array of large-scale industrial applications, like nuclear power facilities, water treatment facilities, petrochemical plants, and other establishments.

We offer all types of controllers at Haygor. Some of the major brands we supply are Yokogawa, Foxboro, Moore, Fisher Controls, Honeywell, and many more. Our complete product line supports control applications of every variety. We even offer models with Ethernet connectivity and active color PV displays.

How Do Controllers Work?

Controllers, often known as proportional-integral-derivative (PID) controllers, continuously calculate an error value for the difference between a desired setpoint and the measured process variable. By adjusting a damper, the power supplied to a heating element, the position of a control valve, or other control variable, the controller tries to minimize error over time.

Controllers have broad uses, since they do not rely on knowledge of any underlying processes. Instead, they are focused on the measured process variable. We can help you choose the right controller for your specific process requirements.

Types of Controllers

Pneumatic Process Controllers

These controllers have relatively easy maintainability thanks to their simple structure. These controllers, which are often energized by compressed air, were once the standard in most industries. Pneumatic process controllers are safe for use around combustibles, such as fire, since there are no electronic components. They are usually considered quite reliable despite being on the slow side.

Electronic Process Controllers

Compared to pneumatic controllers, electronic process controllers typically have a much quicker response time. There is often no transmission delay or time lag. However, there are more potential problems that can arise, since electronic controllers are more complicated.

Most controllers these days are panel-mounted digital controllers or programmable logic controllers. These high tech controllers offer flexible and affordable ways to implement your control system algorithms.

We offer single loop controllers, temperature controllers, program controllers, panel indicators, manual setters, limit controllers, configurational tools, solar tracking controllers, and more. Our controllers can receive many types of measurement, including flow rates, pressures, and temperatures.

Brands We Work With

At Haygor, we sell, service, and repair a variety of controller makes* and models. Here is a sample of that variety:


  • Barton 335, 336, 338 Controllers


  • Fisher 2500-249 Series Pneumatic Controllers and Transmitters
  • Fisher 2860 Series Liquid Level Controllers
  • Fisher 2506 Series Receiver Controllers
  • Fisher Type 4100Z Wizard I Gauge Pressure Controllers
  • Fisher 4150K and 4160K Series Pressure Controllers and Transmitters
  • Fisher 4194 Series Differential Indicating Controllers
  • Fisher 4194H Series Differential Indicating Pressure Controllers
  • Fisher 4195 Series Differential Indicating Pressure Controllers
  • Fisher Type 4660 High-Low Pressure Pilot
  • Fisher 4156K and 4166K Temperature Controllers
  • Fisher 4196 Series Temperature Indicating Controllers
  • Fisher FIELDVUE DLC3000 Series Digital Level Controller
  • Fisher Type 5190 and 5190S Electro-Pneumatic Temperature Controller


  • Taylor 86R and 87R Fulscope Indicating Controller
  • Taylor 155R-164R Fulscope Indicating Controller
  • Taylor 190R and 262R Fulscope Indicating Controller
  • Taylor 440R Pneumatic Indicating Controller
  • Taylor 470R, 670R Quick-Scan Indicating Controller
  • Taylor 541R-544R Transcope Deviation Indicating Controller
  • Taylor 641R-644R Transcope Deviation Indicating Controller
  • Taylor 1400R, 1410R Series Controller

  • Moore Model 25
  • Moore Model 27
  • Moore 352 Controller
  • Moore 55, 55M Pneumatic Controller
  • Moore 352, 353 Controller

Haygor’s team of professionals has more than 50 years of combined experience. We are also committed to customer support. We understand the importance of getting you the right controllers for your purposes in a timely manner.

Please contact us today to get started.

*All product names, logos, and brands are property of their respective owners.