Sky Vent Silencing

Valves within a sky vent system bypass steam around the steam turbine to ensure that the unit does not come up to temperature too quickly. The large pressure differential across the sky vent valve can cause high noise levels that need to be attenuated. Additionally, high temperatures and valve leakage are challenges found in a sky vent application that can lead to degradation of valves and reduced plant load and efficiency. 

Spartan’s Sky Vent Silencing solution uses a noise attenuating control valve and diffuser combination to minimize noise generation. The pressure drop is split between the valve and a downstream diffuser or silencer to reduce noise and high alloy materials and thermally compensated trim designs are utilized to maintain tight shutoff and increase the lifespan of valves. 

Fisher WhisperFlo trim is a concept in multi-path, multistage, acoustic energy management that reduces valve-caused aerodynamic noise by as much as 40 dBA. The performance capability of WhisperFlo trim surpasses conventional noise trims by 5 to 10 dBA and offers a noise attenuation ability that delivers predicted noise levels consistently, avoiding the costly need to recalculate and retrofit valves in order to meet performance promises.