US 4,355,654 AGranted

Fluid flow control device for monitoring the fluid flow in a conduit for leakage of fluid

AssigneeMidland-Ross Corporation

InventorsPaul N. Levesque, Neal M. Lavado

Life of this patent

Estimating the term…

Loading patent…

Abstract

A device for monitoring the flow of fluid in a pair of conduits and blocking the flow of fluid in a conduit when leakage of fluid is sensed therein. The device is provided with, a pair of inlet and outlet passageways in which fluid flows to and from the conduits, a pair of solenoid operated shutoff valves for blocking the flow of fluid in the inlet passageways and a pair of check valves for blocking the backflow of fluid through the outlet passageways. Means are supplied for (a) sensing the flow of fluid through the passageways and translating the same into an electrical signal for comparison with a norm, and (b) actuating the closing of a shutoff valve to block the flow of fluid into a conduit which is connected between an inlet and outlet passageway in which the electrical signal, corresponding to the flow of fluid therein, differs from the norm, the means being designed to delay actuation of the shutoff valve until it is determined that the change in signal from the norm is the result of actual leakage of fluid from the conduit.

Claims13

Dependent claims

A device for monitoring the flow of fluid in at least one pair of conduits attached thereto, and blocking the flow of fluid in at least one of the conduits when leakage of fluid occurs therein, comprising:

(a) a housing;
(b) a fluid inlet through which fluid from a source outside the housing, enters the housing;
(c) a plurality of inlet passageways within the housing for receiving and dividing the flow of fluid entering the fluid inlet into branches, the inlet passageways terminating at a plurality of discharge ports to which fluid conduits are attachable for carrying fluid from the device;
(d) a plurality of reentry ports to which fluid conduits are attachable and through which fluid carried by the fluid conduits is returned to the housing of the device;
(e) an outlet passageway within the housing for each reentry port and communicating therewith for receiving fluid returning to the device, the outlet passageways terminating at a fluid outlet through which fluid exits the device, for example, to return to the source;
(f) means associated with each of the inlet and outlet passageways for monitoring the flow of fluid therein and translating such flow into electrical signals;
and
(g) means responsive to the electrical signals for operating a shutoff valve to block the flow of fluid through an inlet passageway when there is a variance in the electrical signals from a norm, indicating leakage of fluid in a fluid conduit communicating with the blocked inlet passageway.

5 more elements

(a) a housing having a fluid inlet in spaced relation from a pair of discharge ports and a fluid outlet in spaced relation from a pair of reentry ports;
(b) a pair of fluid inlet passageways connecting the fluid inlet and the pair of discharge ports for dividing the flow of fluid entering the fluid inlet into two branches, each of the inlet passageways having a calibrated orifice in the form of a venturi section adjacent the discharge ports;
(c) a shutoff valve in each of the inlet passageways between the fluid inlet and venturi sections for blocking the flow of fluid through the discharge ports, when the valves are moved from open to closed positions;
(d) a solenoid associated with each of the shutoff valves for moving the valves between open and closed positions;
(e) a pair of fluid outlet passageways connecting the reentry ports and the fluid outlet, each of the outlet passageways having a calibrated orifice in the form of a venturi section adjacent the reentry ports;
(f) a check valve in each of the outlet passageways between the reentry ports and venturi sections for preventing the backflow of fluid through the reentry ports, when the valves are moved from open to closed positions;
(g) a pair of flexible diaphragm/piston assemblies disposed within the housing and associated with the venturi sections of an inlet passageway and an associated outlet passageway through which the same branch of fluid passes, each pair of assemblies being movable linearly in response to variations in fluid pressures exerted thereagainst and created by the flow of fluid through the venturi sections, each pair of assemblies including spring means for biasing the assemblies in a neutral linear position between extreme positions which the assemblies can be moved to by a disruption in the flow of fluid through the passageways;
(h) a metal core piece of an LVDT transducer coupled to each pair of assemblies for unitary linear movement therewith, the transducers translating linear movement of their core pieces to electrical signals which are transmitted therefrom, the electrical signals being voltage signals;
(i) an electronic processor for receiving the electrical signals transmitted from the LVDT transducers, the processor including:
(I) means for converting direct electrical current to alternating electrical current;
(II) means for regulating the voltage from a power source to produce a voltage norm at which the device operates;
(III) means for comparing the voltage signals from the LVDT transducers to the voltage norm and actuating a solenoid to cause movement of a shutoff valve to a closed position in the inlet passageway containing the valve, when there is a variation in a signal from the norm, caused by a change in fluid pressure in the outlet passageway associated with the inlet passageway and shutoff valve, sufficient to motivate the processor to actuate the solenoid;
and
(IV) means for delaying actuation of a solenoid until it is determined that the variation in signal from the LVDT transducer from the norm is caused by leakage of fluid in a conduit.

11 more elements

Dependencies are inferred from the claim text.