NDL (Non Dead Leg T Valve) diaphragm valves, with manual or pneumatic actuation, have been specially designed for aseptic processes in the pharmaceutical industry. Valves of this type are widely used at points of use in purified water (PW) or injection water (WFI) circuits.
The principle of operation
The diaphragm serves as both a seal for the body and the seat. Contact of the product with the atmosphere is excluded, which means that the valve can be used in aseptic processes. When the valve closes, the clamp, which serves as a support for the diaphragm, moves towards the sealing surface of the housing. The diaphragm, under the pressure of the clamp, is forced to move onto the seat in the center of the housing, blocking the passage of liquid through the housing.
The valve, with manual or pneumatic drive, can be adjusted by control heads and electric valves.
A standard diaphragm valve completely blocks the flow of the line, and an NDL type valve blocks only one outlet of the main line, this is the main point