Removal and Installation of the Feedback Mechanism of the Flowserve Logix 3800 Positioner



This video demonstrates the removal and installation of the feedback mechanism of the Flowserve Logix 3800 valve positioner.

Make sure the valve is bypassed or in a safe condition. Disconnect power to the positioner. Disconnect air supply to the positioner. Remove the take off arm and follower arm.

Note, it is recommended that when the positioner is removed from the valve, it is taken to a clean work environment for disassembly and reassembly.

Note, the procedure is the same for both intrinsically safe, or explosion-proof, positioners.

Begin by removing the three screws that attach the feedback assembly to the positioner housing. Install the replacement feedback assembly to the positioner housing.

Note, the orientation is irrelevant since the feedback mechanism has a clutch. Torque the screws to 0.9 Newton meters or 8 inch pounds. Next reconnect the positioner follow arm and take off arm to the valve.

For more information, contact Swanson Flo. Visit their web site at https://swansonflo.com, or call them at 800-288-7926.

Happy Holidays from Swanson Flo


A time of peace, a season of wonder and joy... We wish you all the best during the holidays and through the coming year, from your friends at Swanson Flo.

Brewery Valve Application Guide

Download the Brewery Valve
Application Guide Here
Today, beer is one of the oldest beverages humans have ever produced and has spread all over the world. It is a product valued by its physicochemical properties as in its quality and traditional link with culinary and ethnic distinctiveness.

Many types of valves are commonly used in a brewery to regulate the flow of fluids throughout process pipes in a plant.

One type is the diaphragm valve, in which a soft diaphragm is pushed against a bell-shaped feature using a mechanical screw . This mechanism allows gas or liquid flow to be controlled within the valve’s total variability, but the flow pressure tolerances are fairly tight.

The butterfly valve is the next most commonly used valve in breweries due to its compact design and wide pressure and flow tolerances. It consists of a metal disc which rotates within the body of the valve and closes against a rubber seal. Its flow-through design makes it easy to clean.

The Brewery Valve Application Guide, located on Swanson Flo web site, provides a quick reference on the various processes involved in brewing and what type of valves are used for those processes.

Changing VR Actuator Orientation on Valtek Rotary Valves, including Valdisk, Shearstream and MaxFlo


The Valtek VR rotary cylinder actuator is a high pressure, compact actuator with high torque and pneumatic stiffness for excellent throttling capabilities. The standard splined shaft connection eliminates backlash for precise control. This video shows how to change the orientation on a Valtek Rotary Valves including Valdisk, Shearstream and MaxFlo products.

For more infomration on Valtek Control Valves, contact Swanson Flo by calling 800-288-7926 or by visiting https://swansonflo.com.

Swanson Flo Salutes Our Veterans

Veterans Day

Veterans Day is set aside to honor the men and women who have sacrificed so much in order to serve in the armed forces of the United States.

Veterans Day celebrates and thanks all United States military veterans,  alive or dead, and honors the sacrifices that they have made. Our Veterans are our neighbors, friends, family, and co-workers. They took an oath to defend the United States and our Constitution, from all enemies, foreign and domestic. We must never forget their bravery, service, and sacrifice.

Originally called Armistice Day because of the November 11 Armistice that ended World War I, its name was officially changed in the United States in 1954 to Veterans Day to include Veterans of all wars.

Through the observance of Veterans Day, we remind ourselves of our Veterans patriotism, love of country and willingness to serve and sacrifice for the common good.

Swanson Flo celebrates and honors America's veterans.

Electric Valve Actuation

Electric actuator
Electric Valve Actuator in Service (Limitorque)
Electric actuators use electrical power to actuate a valve. While most of the basic technology used in electric actuators has been around since the 1930s, decades of incremental improvement have significantly increased their functionality while dramatically reducing their cost. In recent years, these advances have reached a tipping point that makes electric actuators the first choice for a wide variety of applications.



Electric Valve Actuation Advantages


  • Electric power is relatively inexpensive, easy to manage, and normally available to most industrial sites. The capital cost of electric actuators is typically cheaper per equivalent unit of torque/thrust output. They’re also cleaner and safer to operate.
  • Electric actuators can provide superior positioning accuracy for control or modulating valve functions, which can include provisions for a high degree of process monitoring, data logging and information feedback.
  • All necessary control functions are integral to electric actuators, reducing capital costs.
  • Electric actuators significantly reduce control wiring costs by enabling distributed control. They simplify control logic by integrating control commands and feedback into customer SCADA or DCS systems. (Traditional electromechanical control systems require a dedicated wire for each command and feedback signal, leading to cable bundles with seven or more cores as minimum for each actuator. By contrast, a typical bus system can use one twisted pair wire in a daisy chain configuration to carry all required input and output signals.)
  • As torque and thrust requirements increase, electric actuators weigh less and have smaller footprints compared to pneumatic actuators.
  • Electric actuators may be combined with external gearboxes to produce extremely high output thrust and torque values.

Electric Valve Actuation Disadvantages


  • With the exception of a few specific configurations, electric actuators can’t guarantee a fail-safe stroke but will “fail in the last position.” (Fail-safe stroke refers to an actuator’s ability to move a valve to a predefined safe position when power fails).
  • Electric actuators have more complex and sensitive components than the mechanical parts used in other types of actuators. Electronic technology also requires periodic refreshing to keep pace with component changes and improvements.
  • Beyond a certain size/torque range, electric actuators are less cost-effective and generally have limitations in operating speed when compared to pneumatic and hydraulic actuators.
  • In hazardous areas with potential exposure to explosive process media, electric actuators require more specific certifications and construction features to be considered safe for use.

Recommended applications for electric actuation.


Electric actuation is the first choice for most oil and gas applications. They’re ideal for general process valve automation, non-critical applications, and light-duty modulating applications (generally up to 1200 starts per hour), although some can modulate continuously up to 3600 starts per hour.

For more information about electric valve actuation, contact Swanson Flo. Call them at 800-288-7926 or visit their web site at https://swansonflo.com.

Reprinted with permission from Flowserve Limitorque.