Valve and a method of closing a valve

Method for the closing of a valve with a through-going axial bore, a first spindle axially displaceable in the bore, an elastic/flexible seal placed at the one end surface of the first spindle, at least two hollow connection branches for withdrawal of samples, each of which connects the valve to an outer coupling, said first spindle moving in an axial movement towards the bottom of the inner body of the valve in bringing about a first position, in which position a first seating forms an annular sealing surface between the outer surface of the seal and the inner bottom of the valve body which contains an inlet opening;

• and a second spindle, in which spindle the first spindle is disposed, the second spindle being movable downwards into its bottom position by an exclusively axial movement for the formation of a second seating in a second position;
• comprising the steps of:
• operating the valve to an open state in which both spindles are moved to respective open positions in which the outer surface of the seal is withdrawn from the first and second annular seating surfaces, whereby a sample is taken from the inlet opening and communicated to one of the connection branches,
• operating the valve to a cleaning state in which the first spindle is moved to a closed position to engage the seal with the first annular seating surface while the second spindle remains at the open position with the seal withdrawn from the second annular seating surface, whereby the second annular seating surface remains exposed to disinfection by introducing a disinfecting fluid through one of the connection branches;
• operating the valve to a transition state in which the second spindle is moved to a closed position to engage the seal with the second annular seating surface while the first annular seating surface remains closed, whereby the disinfected second annular seating surface remains uncontaminated;
• and
• operating the valve to a closed state in which the first spindle is moved to the open position in which the seal is withdrawn from the first annular seating surface and the second spindle remains at the closed position, whereby the inlet opening is open to sample material while the second annular seating surface remains closed to the connection branches.