Torque issues with eccentric butterfly valves
Thread Content
As shown in the figure, could some expert help derive how this formula was obtained?
These are the formulas from the valve design manual compiled by Lu Peiwen. The earliest versions of these formulas originated from valve manuals from the 1960s, specifically those related to center-line butterfly valves; they come from a valve manual dating back to around 1966. The tolerances specified in these formulas are too large – they’re fine for manual control, but if these formulas are used to select cylinders or electric actuators, it’s likely to result in significant losses
Indeed, it’s been almost sixty years since that formula was developed; materials have changed significantly over those decades
Indeed, according to the formulas in the manual, the torque is significantly high