Abstract: A capacitive proximity monitoring device for corrosive atmosphere environments comprising a capacitance field element or sensing element disposed in such a corrosive atmosphere environment and being made of conductive plastic resistant for such a corrosive atmosphere environment. The field element may be a functional part of a functional device that performs a function with respect to the presence of the liquid being sensed; and in some cases the field element is nonfunctional with respect to the liquid, but functional and sensing the capacitance and determining the presence or absence of liquid.

Abstract: A capacitive proximity monitoring device for corrosive atmosphere environments comprising a capacitance field element or sensing element disposed in such a corrosive atmosphere environment and being made of conductive plastic resistant for such a corrosive atmosphere environment. The field element may be a functional part of a functional device that performs a function with respect to the presence of the liquid being sensed; and in some cases the field element is nonfunctional with respect to the liquid, but functional and sensing the capacitance and determining the presence or absence of liquid.

Abstract: A plastic valve comprising a valve body, integral plastic valving duct means with rigid tubular plastic end portions for attachment to flow ducts carrying liquids to be valved, and a collapsible and distensible tubular plastic valving portion welded to the tubular end portions, the valving portion have sidewalls of plastic film laminae free of each other, but welded to each other at edges to form resilient side rib portions, squeezing linkages traversing flexible wall portions and applying squeezing pressure onto the flexible wall portions to close the flow passage therebetween, tiltable squeeze bars extending along the flexible wall adjacent the squeezing linkages and progressively deforming the flexible wall portions during application of squeezing pressure, camming impeller portions applying and relieving squeezing pressure against the squeezing linkages and squeeze bars and camming against the camming surfaces of the body portion as a driving head moves the impeller portions in the valve body portion.