Noise and velocity control
High-velocity gases result in high noise levels and unwanted vibrations in chokes.
Noise and velocity calculations are part of JVS sizing software. The design of JVS chokes and orifice is such as to keep these two parameters within limits specified by the customer and industry standard. JVS chokes reduce the noise produced by chokes by employing the following two methods through its multistage orifice design.
Pressure drop staging
Instead of taking the entire pressure drop in one step, the pressure drop is divided up into two or more steps, due to which individual velocity peaks are smaller than the velocity peak that would result from a single stage pressure drop. Small reductions in pressure keep energy of fluid under control and help in reducing choke exit velocity and noise level.
Pressure drop staging using 5 stages energydissipation multistage orifice
Instead of having the flow pass through a single opening, the flow is divided up so that it passes through several openings in parallel.
The reduction is due mainly to the fact that the smaller openings shift the noise to a higher frequency. The higher frequencies are attenuated more as the sound passes through the pipe wall, than the lower frequencies. Also, because the human ear, and the "A" weighting curve on noise meters, attenuate higher frequencies, both the measured and perceived noise is decreased.