Patent ID: 6929026
Filing Date: 2005-08-16
Classification: G05D,Y10T

Abstract:
1. A liquid pressure building valve comprising: a liquid housing defining a liquid flow passage having a diaphragm assembly comprising a diaphragm having a liquid side forming a portion of the liquid inlet passage, and an opposed control side, the diaphragm being moveable along a central axis; a control housing comprising a control means for applying a control force to the control side of the diaphragm; a valve plug positioned on the liquid inlet passage side of the orifice means, and having a first side affixed to the liquid side of the diaphragm assembly, for movement of the valve plug along the central axis with the moveable diaphragm, to a position relative to the orifice means opening, whereby an orifice is formed between the orifice means opening and the valve plug, the orifice having a variable effective area as a function of the position of the valve plug, the valve plug having an opposed second side having a second surface in liquid communication with the liquid outlet passage, where against a liquid in the liquid outlet passage can exert a backpressure force against the diaphragm; a pressure receiving means in liquid communication with the liquid outlet passage, upon which a liquid in the liquid outlet passage can exert a balancing force; and a means for communicating the balancing force to the diaphragm opposing the backpressure force.