Abstract: A valve for use in a fluid dispensing system, the valve includes a valve body having a valve passage therein, having first and second ends, the second end including a valve seat. The valve also includes a valve stem having an end portion extending into the valve passage constructed to permit the flow of fluid through the passage past the end portion. The valve stem has sealing means for closing the second end of the passage, and is mounted for reciprocal movement in the valve passage between an extended position in which the sealing means on the valve stem engages the valve seat and closes the second end of the valve passage, and a retracted position in which the sealing means is spaced from the valve seat so that fluid can flow through the valve passage past the end portion of the valve stem. A spring resiliently biases the valve stem toward its extended position. The spring is protected from the fluid flow through the valve by a flexible annular sealing disk.

Abstract: Cell culture filter apparatus and method is disclosed for the large scale cultivation of mammalian cells. This system is adapted for convenient manual assembly - disassembly of internal parts and interchangeability of filtration units.