Sky Vent Control Valve Solutions
Silence noise and maintain a tight shutoff of your sky vent system.
- Automation Solutions
- Industrial Process Valves & Instruments
- Control Valves
- Sky Vent Control Valve Solutions
Silence noise and maintain a tight shutoff of your sky vent system.
Control valves within a sky vent system of a power plant bypass steam around the turbine to the atmosphere to ensure the unit doesn’t come up to temperature too quickly. Sky vent control valves are crucial to operational efficiency by working quietly during dump operation and providing tight shutoff during normal operation, preventing valuable steam leakage. They face the following challenges:
Sky vent control valves often have failures resulting from damages to the positioner caused by high-temperature radiation and/or piping vibration. Conventional positioners used on these valves also tend to suffer from inaccuracy and failures due to wear and tear of the mechanical linkages. These failures can lead to unplanned downtime and production losses.
Linkage-less, non-contact Fisher FIELDVUE digital valve controllers are paired with Fisher control valves to improve sky vent valve performance and reliability. With no linkage to wear, loosen, corrode, or vibrate, FIELDVUE digital valve controllers can handle harsh environments. A remote mount option is suited for high ambient temperature and/or piping vibration.
In normal operating conditions, sky vent valves will remain closed most of the time. They are required to provide tight shutoff during normal operation and prevent any valuable steam or process fluid from leaking. It is a challenge for most valve vendors to design long-lasting and good sealing technology to operate at full pressure drop and high-temperature conditions where elastomer seals are not able to withstand.
The Fisher Bore Seal employs a metal C-shaped ring that is secured to the outside diameter of the valve plug. When the valve plug comes into contact with the seat ring to close the valve, the Bore Seal is compressed against the cage wall thereby blocking a secondary leakage path that exists between the plug and cage wall.
Sky vent valves will be in the closed position during normal operation. However, during startup, steam vent valves bypass steam around the turbine to ensure the unit does not come up to temperature too quickly. The large pressure differential across steam vent valves at initial plant startup can cause high noise levels that need to be attenuated. Vibration caused by aerodynamic sound pressure may eventually damage equipment and shorten operating life.
Fisher valve trims accomplish noise attenuation by utilizing unique pressure control of flow through the valve and diffuser or silencer. Fisher Whisper Trim III cages achieve up to a 30 dBA noise reduction.
Case Study
Improve energy efficiency and minimize your carbon footprint with the Fisher sky vent solution.
Case Study
Leverage Fisher valves, actuators, and instruments to reduce operating costs and improve your plant flexibility, availability, and reliability.
