Bioprocess flow system
A valve configured to be in a first state, which is an open state when a flow through the tube should be allowed; a second state during some parts of a process run in the system, said second state is a closed state were a first closing force is provided; and a third state during some parts of a process run in the system, said third state is a closed state were a second closing force is provided which is a higher force than the first closing force.
1. A valve, wherein said valve is configured for being provided in three different states, whereof:
a first state is an open state where a tube provided with said valve is kept open for allowing flow through the tube;
a second state and a third state are closed states but with different closing forces, whereby a tube provided with said valve is closed for flow in both these closed states but with a higher closing force in the third state than in the second state; and
wherein the valve comprises a control system which is configured for controlling the valve to be provided in the three different states, wherein the control system is operable to apply the different closing forces to the valve in response to a fluid pressure within the tube.
2. The valve according to claim 1 , wherein said valve is provided in said second and third states by urging a flexible material into sealing contact with a surface.
3. The valve according to claim 1 , wherein said valve is a pinch valve and
said second state is a closed state preventing flow through the tube provided with said valve, wherein flow is prevented by pinching the tube with a first closing force, which first closing force is adapted to stop the flow in the tube at a first fluid pressure in the tube; and
said third state is a closed state preventing flow through the tube provided with said valve, wherein flow is prevented by pinching the tube with a second closing force, which second closing force is adapted to stop the flow in the tube at a second fluid pressure in the tube which is higher than the first fluid pressure in the tube.
4. The valve according to claim 1 , wherein said valve is a membrane valve and
said second state is a closed state preventing flow through the tube provided with said membrane valve, wherein flow is prevented by moving a membrane of the membrane valve towards a valve seat of the membrane valve with a first closing force, which first closing force is adapted to stop the flow in the tube at a first fluid pressure in the tube; and
said third state is a closed state preventing flow through the tube provided with said membrane valve, wherein flow is prevented by moving a membrane of the membrane valve towards a valve seat of the membrane valve with a second closing force, which second closing force is adapted to stop the flow in the tube at a second fluid pressure in the tube which is higher than the first fluid pressure in the tube.
5. The valve according to claim 4 , wherein said membrane valve comprises a tube for connection of a hydraulic/pneumatic chamber of said membrane valve to a hydraulic/pneumatic control system, wherein said tube comprises a sterile filter.
6. The valve according to claim 1 , wherein said control system is configured for controlling the valve to be in the third state with the highest closing force when a tube provided with said valve should be closed for not allowing flow through the tube during pumping of a fluid through the tube and said control system is configured for controlling the valve to be in the second state with the lower closing force when a tube provided with said valve should be closed for not allowing flow through the tube when fluid is not pumping through the tube.
7. The valve according to claim 1 , wherein said control system is configured for controlling the valve by pneumatic air or hydraulic fluid.