Double-diaphragm gauge protector

A double-diaphragm gauge protector comprising:

• a diaphragm housing comprising:
• a upper housing body;
• a lower housing body;
• and
• a central housing body having an annular passage therethrough interconnected between the upper and lower housing bodies;
• a first diaphragm disposed within the upper housing body, wherein the upper housing body has an inside dimension smaller than an outer dimension of the first diaphragm for imposing a radially inward directed circumferential loading force on the first diaphragm, and wherein the first diaphragm includes a centrally located transfer pad that projects outwardly away from a downwardly facing bottom surface of the first diaphragm toward the lower housing body;
• a second diaphragm disposed within the lower housing body, wherein the lower housing body has an inside dimension smaller than an outer dimension of the second diaphragm for imposing a radially inward directed circumferential loading force on the second diaphragm, and wherein the second diaphragm includes a centrally located transfer pad projecting outwardly away from an upwardly facing top surface of the second diaphragm toward the first diaphragm, wherein the transfer pads of the first and second diaphragms are positioned facing one another;
• and
• a free-floating donut-shaped spacer disposed within the central housing body and interposed between the bottom and top surfaces of the first and second diaphragms, respectively.

A double-diaphragm gauge protector comprising:

• a diaphragm housing comprising:
• a upper housing body having a pressure outlet port extending though a body wall for accommodating connection with a pressure measuring or sensing device;
• a lower housing body having a process fluid or gas inlet port through a body wall for accommodating connection with a fluid or gas handling device;
• and
• a central housing body having an annular passage therethrough interconnected between the upper and lower housing bodies;
• a first diaphragm disposed within the upper housing body and forming an upper chamber therebetween, wherein the upper housing body has an inside dimension smaller than an outer dimension of the first diaphragm for imposing a radially inward directed circumferential loading force on the first diaphragm, and wherein the first diaphragm includes a centrally located transfer pad that projects outwardly away from a downwardly facing bottom surface of the first diaphragm toward the lower housing body;
• a second diaphragm disposed within the lower housing body and forming a lower chamber therebetween, wherein the lower housing body has an inside dimension smaller than an outer dimension of the second diaphragm for imposing a radially inward directed circumferential loading force on the second diaphragm, and wherein the second diaphragm includes a centrally located transfer pad projecting outwardly away from an upwardly facing top surface of the second diaphragm toward the first diaphragm, wherein the transfer pads of the first and second diaphragms are positioned one on top of the other;
• and
• a free-floating donut-shaped spacer disposed within the central housing body and interposed between bottom and top surfaces of the first and second diaphragms, respectively, wherein the transfer pads of both the first and second diaphragm are disposed within a central opening of the spacer.

A method for accurately transmitting a pressure force from a process fluid or gas outlet to a pressure measuring or sensing device using a gauge protector comprising a first and second diaphragm, the method comprising the steps of:

• directing process fluid or gas into a first chamber comprising a second diaphragm;
• allowing the process fluid or gas to impose a pressure force against an adjacent surface of the second diaphragm, causing the second diaphragm to move toward a first diaphragm;
• transferring the movement of the second diaphragm to the first diaphragm by contacting adjacent first and second diaphragm transfer pads, wherein one transfer pad projects outwardly away from a surface of the second diaphragm opposite the surface in contact with the fluid or gas, and wherein another transfer pad projects outwardly away from a surface of the first diaphragm that faces the second diaphragm, and by contacting remaining facing surface portions of the second and first diaphragms through a free-floating spacer interposed between the diaphragms, wherein the movement of the second diaphragm is transferred to the first diaphragm in a separate second liquid-free chamber;
• and
• transferring movement of the first diaphragm to a pressure force within a separate liquid filled third chamber connected to the pressure measuring or sensing device.