Datasheet BD damper valves
We've already made some slide valves to go under the biomass dome storage silos. At the top of the silos there are some dust filters to clean the displaced air. Occasionally the filter media in these needs to be changed so we've made some 2.2m diameter butterfly damper valves that can be closed, locked and used as a safe working platform for the personnel changing the filter media.
They're manually operated by big worm-wheel gearboxes and have a ledge seat for the vane to sit against. When closed, there is a safety lock that prevents the valve from opening even if the actuator handwheel is turned.
We've pressure tested them to 1.1 bar in case the storage silo has a problem below.