It is impossible not to allow the entrance of air.
The water column sucks air by the small passages of the packing.
I read the indicated article. The tap seems a good solution. I am verifying the possibility of installs it.
The installed valve is anti-slam, however it does not function...
It is an "slow closing valve", a type of air/vacuum valve with a float inside and a special designed chamber to release the air of vertical pumps and other necessities.
When the vertical pump starts, the air inside the column (above the water level) will be forced by the water pumped to escape by the slow closing valve- there is a check valve, just after the valve, retaining downstream water. The water velocity in the column depends on the velocity of air...
We have an slow closing valve in the end of a vertical pump column which does not function correctly. The float is being kneaded. We are thinking to install an orifice plate in the flange of the base of the valve to reduce water hammer.This will help to solve the problem? Or it has another...