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Class Information
Number: 137/424
Name: Fluid handling > Liquid level responsive or maintaining systems > By float controlled valve > With counter-balance
Description: Apparatus in which the float is provided with means to apply a force which at least partially counterbalances the weight of the float and valve assembly or which partially counterbalances the buoyancy of the float.

Sub-classes under this class:

Class Number Class Name Patents
137/425 Within tank 17

Patents under this class:

Patent Number Title Of Patent Date Issued
7520296 Device to adjust and control water levels Apr. 21, 2009
5975131 Tank valve and opening sensor Nov. 2, 1999
5755257 Retention gate May. 26, 1998
5141644 Buoyed flapper valve Aug. 25, 1992
4838303 Buoyancy operable liquid level sensor for controlling an alarm pressure fluid supply responsive to changes of liquid level in a pressure vessel Jun. 13, 1989

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