Modular thermal expansion valve and cartridge therefor

摘要

An improved thermally responsive expansion valve (10) for use in controlling flow of refrigerant in a circulating system has a cartridge sub-assembly (12) with a fluid charged diaphragm capsule (14), an operating rod mechanism (50), a valve seat (40) and captured valve obturator (44). A tubular extension (38) with the valve seat (40) is adjustably threaded onto the capsule (14). The cartridge subassembly (12) may be thermally pre-calibrated before installation in a blind bore in a valve body. During calibration, the tubular extension (38) is rotated to adjust the diaphragm (20) and operating rod mechanism (50) to provide the desired obturator movement from the valve seat (40) at the calibration temperature. <IMAGE>