Device for regulating the negative pressure in a pressurized line system, in particular for milking facilities

摘要

A device for regulating the vacuum in milking installations has a main valve and an auxiliary valve. A main valve chamber is connected with the atmosphere and, through a valve seat to the vacuum line. A control chamber is closed off from the main valve chamber by a first membrane and from the atmosphere by a second membrane. Both membranes are joined to a movable support bearing the main valve body, which presents active surfaces of different size to the main valve chamber and to the atmosphere. The position of the main valve is dependent upon the pressure in the control chamber, which pressure is determined by the auxiliary valve which is disposed in the support. The auxiliary valve has two auxiliary chambers separated by an auxiliary membrane to which the auxiliary valve body is fastened. The first auxiliary chamber is connected to the vacuum line and the second auxiliary chamber is connected to the atmosphere. The position of the auxiliary valve is dependent upon the pressure difference in the auxiliary chambers and the force of an adjustable spring acting on the auxiliary valve body. The control chamber and first auxiliary chamber are connected to the vacuum line by a passage disposed centrally thereof.