The most common types that are used are:

– Guillotine or Coulisse shutter

– Butterfly shutters or valves

The substantial difference between the two models is the passage section of the material.

In the guillotine model, when the shutter is open, the total section of the pipe is free and of course there are no obstacles for the passage material, even if it’s a long type.

In the guillotine shutters the pressure drop is close to zero:

• the pull flow of the normal plants is suitable for the pressed model, while for higher pull flow value,

• we suggest the Reinforced shutters or the ones with sealing gasket; the advantage of this model is to eliminate any whistling noise caused by small leaks.

– Butterfly Shutters are indicated for systems where there are no stringy or long materials as the diaphragm is fixed on a transversal pin to the pipe which, in the open position, becomes an obstacle and possible hitch if the passage material is long.

They can also have the sealing gasket with the advantage of 98% sealing and reduction of pressure drop and noise caused by the air. Their structure allows a high working pull flow and minimum encumbrance around the pipe.