PRESSURE DIFFERENTIAL INDICATOR

摘要

A pressure differential indicator that eliminates the risk of providing a false positive due to fluid contamination. The invention has an electrically insulated barrier between the “hot” pin and the grounded housing without the need for a hermetic seal. The indicator can be manufactured at a greater efficiency and lower cost than is found with prior art pressure differential indicators. It has a piston that can be easily oriented to yield either a normally closed or normally open position. The indicator has at least one protrusion on a plastic overmold to engage the swage collar and resist axial rotation of the pin. A pressure seal interrupting the plastic overmold sections and exposing the underlying metal to allow for an O-ring seal with no potential leak path between plastic and metal. Finally, the pressure differential indicator has all moving components contained within a single cavity.

主权项

1. A pressure differential indicator for a fluid filter having a manifold associated therewith, wherein said manifold having a threaded section in communication with a downstream clean fluid port and an upstream dirty fluid port, said pressure differential indicator comprising:
a cylindrical hollow metal electrical conductive housing which is grounded, said housing having a manifold end and a pin end as well as a threaded section between the pin end and the manifold end of said housing and, said housing having a hexagonal nut section machined therein, wherein said housing screws into the threaded section of the manifold associated with the fluid filter by using said hexagonal nut section and wherein said housing further having an external first O-ring and an internal first O-ring adjacent to the manifold end wherein said first external and first internal O-rings separate the downstream fluid from the upstream fluid; a electrically conductive pin having a power end and a piston end wherein said pin provides electrical power to said pressure differential indicator, a non-conducting washer encircling said pin to electrically insulates said pin from said housing which is grounded, a swage collar on said housing, immediately adjacent to said non-conducting washer and also encircling said pin to keep said pin axially secured with said housing, a second external O-ring immediately adjacent to said hexagonal nut section encircling said housing wherein said second external O-ring wherein said second external O-ring prevent dirty fluid from escaping; a high pressure port in said housing positioned between said second external O-ring and said first external O-ring wherein said high pressure port is in communication with the upstream dirty fluid port of said manifold such that the pressure differential between the downstream clean fluid port and the upstream dirty fluid port can be measured to determine when the fluid filter needs to be changed.