Pressure transmitter with stress isolation depression

A pressure transmitter for measuring differential fluid pressure between first and second pressure sources having respective first and second fluid pressures, comprising:

• a housing having a housing outer rim encompassing first and second housing inner rims, the first and second housing inner rims defining first and second housing openings, respectively;
• first and second isolation diaphragms sealingly disposed across the first and second housing openings, respectively;
• means for sensing pressure disposed in the housing providing a sensor output and coupled to the first and second isolation diaphragms;
• flange means for coupling the first and second fluid pressures to the first and second isolation diaphragms, respectively, having a flange outer rim abutting the corresponding housing outer rim, the flange means having first and second flange inner rims facing the corresponding first and second housing inner rims and defining first and second recesses therebetween, respectively, the flange means having first and second passageways coupling the first and second fluid pressures from first and second flange openings defined in the flange means, respectively, to a third and fourth flange opening defined by the first and second flange inner rims, respectively, the third and fourth flange openings coupling the first and second fluid pressure to the first and second isolation diaphragms, respectively;
• sealing means disposed in the first and second recess, respectively, for sealing the first and second housing inner rims to the first and second flange inner rims, respectively;
• securing means coupled to the flange means for securing the flange outer rim and housing outer rim together such that the housing outer rim receives a securing force from the flange outer rim and the first and second housing inner rims receive first and second sealing forces, respectively, from the first and second flange inner rims, respectively, via the sealing means;
• and
• flexure means defined by at least one depression in the housing between the first housing opening and the housing outer rim for reducing transmission of the securing force from the housing outer rim to the first isolation diaphragm means.

A pressure transmitter for measuring a fluid pressure from a pressure source, comprising:

• a housing having a peripheral inner rim defining a housing opening;
• means for sensing pressure disposed in the housing within the perimeter of the housing inner rim providing a sensor output and coupled to the housing opening;
• flange means for coupling the fluid pressure to the means for sensing pressure and having a flange outer peripheral rim and a flange inner rim facing the corresponding housing inner rim, the flange means having a passageway communicating the fluid pressure from a first flange opening defined in the flange means to a second flange opening defined by the flange inner rim, the second flange opening coupling the fluid pressure to the means for sensing pressure;
• sealing means for sealing the housing inner rim with respect to the flange inner rim when the flange is secured to the housing;
• securing means for securing the flange and housing together with a securing force acting in a first direction;
• and
• flexure means comprising a housing outer rim forming a narrow peripheral rim separated from the housing inner rim by at least one depression in the housing, the flange outer peripheral rim contacting the flange outer peripheral rim to flex the housing outer rim to react the securing force exerted by the securing means in the first direction for reducing transmission of the securing force from the housing outer rim to the means for sensing pressure.