Abstract: A leak detection device securable in detection proximity to a fluid vessel. The leak detection device includes a sensor element and a monitoring assembly. The sensor element has a monitorable characteristic, and the monitorable characteristic changes upon contact, immerson or in exposure to the fluid contained in the vessel. The monotoring assembly is responsive to the monitorable characteristic and produces an changing electrical output in response to change in the monitorable characteristic. The vessel and leak detection device may form an assembly including a shroud or cover over the detection device and a leak-susceptible portion of the vessel, to provide a microenvironment in which the detection device is operated.

Abstract: A variable restrictor for controlling flow rate including a ferrule formed of a yieldable material and having an opening at one end cooperating with the carrier line delivering fluid thereto. A passageway in the ferrule communicating with the carrier line terminates at the opposite end of the ferrule which is provided with a conical-shaped end portion cooperating with a recess of a conforming taper provided in a member having a passageway communicating with the utilization device receiving the fluid. The flow rate is regulated by controlling the position of the ferrule relative to the cooperating recess which controls the amount of compression exerted upon the forward end of the ferrule and hence the amount of constriction of the passageway extending therethrough.

Abstract: A system for maintaining back-pressure in chemical laboratory testing apparatus includes a modified flow control valve governed by a special control system which includes an input/output controller. That controller includes a microprocessor and memory into which a program developed specifically for the modified valve has been placed. A pre-pressure valve is also used upstream of the instrument in which the pressure is to be maintained for effecting quicker control of the pressure. The input/output controller, in conjunction with the servo-amplifier, integrates out the error between the desired set-point pressure and actual pressure thereby enabling maintenance of pressure within one pound.