Challenging Steam Balancing Valve Application at Southwest Power Plant

Steam Balance Valve
Steam balance valve
with Kinetrol model 30.
In combined-cycle power generation plants, the most common design for managing high-pressure steam is with cascading bypass systems. Balancing valves are used on the hot reheat line to respond to control loop demands. The application is difficult because of high pressures, high temperatures, and large valve sizes (high torque). The valves must shut off tightly and also be capable of precise throttling.

Outfitting these valves with pneumatic actuators is also difficult. Because of the valve size and valve design, actuators must have high torque output, without taking up vast amounts of space. The actuators must also act quickly and eliminate hysteresis.

Most pneumatic actuator designs simply cannot meet the operating and size restrictions, and hydraulic actuators, with all of their associated maintenance problems, are used instead.

A Kinetrol Distributor in the Southwest USA was asked to recommend a better alternative to a line where very large scotch-yoke actuators controlling two (2) 18" valves were controlling poorly and were taking up too much space.

The Distributor's challenge was to:
  • Deliver very high torque output.
  • Provide as small a package as possible.
  • Improve the actuators stability and reliability.
The solution was to apply Kinetrol model 30 vane actuators. The model 30's deliver 168,000 lbf (at 100 psi) of torque in a compact envelope (comparatively). Additionally, the Kinetrol Model 30's, combined with third-party digital valve positioners, provided the precision and response the application required to eliminate oscillations and instability.  The actuators cycle about 20 times per day and have been performing without problem for years. Huge annual fuel savings can be directly attributed to the actuators reliability and precision due to fewer turbine restarts.

Steam Balance Valve
Power plant steam balancing valves in service.

For more information, contact Kinetrol USA by visiting https://kinetrolusa.com or by calling 972-447-9443.

New EL Positioner Installation Video from Kinetrol USA

The video below is new from Kinetrol USA and provides detailed instructions on how to install a Kinetrol model EL electro-pneumatic positioner.

The EL positioner controls airflow to an actuator and moves it to a position determined by a 4-20mA signal and using a unique low power proportional servo valve. The combination of EL positioner and Kinetrol vane actuator provide fast, smooth and precise control for industrial valves and dampers.


A Review: Why Kinetrol Actuators Are the Most Reliable 1/4 Turn Pneumatic Actuator on the Market Today

With millions of actuators performing reliably around the world, the Kinetrol vane actuator's are the best choice for valve and damper actuation applications that require long life and ultra-dependable performance. Here's a review as to why:

Kinetrol Actuators
Click on image for larger view.
  • Durable epoxy stove enamel exterior finish.
  • Long life epoxy or PTFE internal finish.
  • Integral vane/shaft casting - only one moving part: Simplest and most reliable mechanism for quarter-turn rotary actuation.
  • Manual override square and position indicator.
  • Stainless steel expanders ensure long term lipseal / case contact.
  • Double opposed, Polyurethane, lip seals for effective sealing and long maintenance free life.
  • Space filling/energy absorbent sideplates (polymer or metal).
  • Corrosion resistant zinc (non-incendive) or aluminum alloy case.
  • Easy stop adjustment at each end of stroke for accurate seating.
  • Close couple control modules. Fail-safe spring returns, limit switches, positioners and solenoid valves all close couple to the actuators.
  • No cranks or gearing. No power loss or backlash - allows accurate positioning.
  • Long maintenance-free life. Up to 4 million operations guaranteed.
  • Compact - space saving - efficient. Best torque/size package available, fast operating speeds, best air consumption, proven design.
  • Unique serial number for identification and traceability.
For more information, visit https://kinetrolusa.com of call 972-447-9443.