초록 ▼

A combination high pressure switch-low pressure switch and high pressure relief valve control device is disclosed having series connected high and low pressure switches which are held closed to complete a control circuit in a normal pressure operating range and are respectively responsive to pressur

A combination high pressure switch-low pressure switch and high pressure relief valve control device is disclosed having series connected high and low pressure switches which are held closed to complete a control circuit in a normal pressure operating range and are respectively responsive to pressures above and below this range to open the control circuit. A high pressure relief valve is also integrated into the control device and operates to provide high pressure relief to atmosphere at pressures substantially above the high pressure switch actuating pressure.

대표청구항 ▼

A combination high pressure switch-low pressure switch and high pressure relief valve control device comprising: an electrically conductive housing adapted to be electrically grounded on mounting in a pressure control installation, low pressure switch means and high pressure switch means mounted in

A combination high pressure switch-low pressure switch and high pressure relief valve control device comprising: an electrically conductive housing adapted to be electrically grounded on mounting in a pressure control installation, low pressure switch means and high pressure switch means mounted in said housing and operatively electrically connected in series thereof for adaptation in a control circuit, said low pressure switch means including biasing means for urging opening thereof, force transmitting means mounted in said housing having pressure sensing means adapted to be exposed to a pressure to be sensed for normally holding said low pressure switch means closed and responding to pressures below a predetermined low pressure value to effect opening of said low pressure switch means by its biasing means, said high pressure switch means including biasing means for urging closure thereof, said force transmitting means being further responsive to pressure on said pressure sensing means above a predetermined least extreme high pressure value to open said high pressure switch means against its biasing means whereby said high and low pressure switch means cooperatively provide an electrically conductive path to said housing only between said predetermined low pressure value and least extreme high pressure value, and high pressure relief valve means mounted in said housing having biasing means for urging closure thereof, said high pressure relief valve means further having pressure sensing means adapted to be exposed to the pressure to be sensed for responding to pressures above a predetermined most high pressure value substantially higher than least extreme pressure value to open said high pressure relief valve means to provide extreme high pressure relief.