Fluid handling – Diverse fluid containing pressure systems – Fluid separating traps or vents
Reexamination Certificate
1999-08-24
2001-01-09
Michalsky, Gerald A. (Department: 3753)
Fluid handling
Diverse fluid containing pressure systems
Fluid separating traps or vents
C137S510000
Reexamination Certificate
active
06170511
ABSTRACT:
FIELD OF THE INVENTION
The present invention relates, in general, to a valve for purging contaminant liquids from a conduit which at times contains a pressurized gas and, more particularly, the instant invention relates to a valve for purging contaminant liquids from a railway vehicle brake air line which is normally unpressurized.
BACKGROUND OF THE INVENTION
The invention specifically applies to the independent brake line of a locomotive, for example, to the 20 Line in the EPIC
a
3102 Braking system.
The independent brake system of a locomotive operates independently of the automatic airbrake system which includes the brake air line which is connected between all the railway cars in a train. The independent brake system applies brakes only on the locomotive. It is used, for example, when a locomotive is not connected to other railway cars, but is moved independently, for example, within a switchyard or a maintenance facility.
The independent brake system of a locomotive has a brake air line which is pressurized to apply brakes on the locomotive and is depressurized to release brakes. The independent brake system works in a manner exactly opposite to the automatic airbrake system of a train, in which the brake line is pressurized to remove brakes and depressurized to apply brakes.
In addition to its use for controlling an isolated locomotive in a switchyard or maintenance facility, the independent brake system is also used on other occasions when it is desired to apply brakes in the locomotive, but not in the other railway cars. For example, it is generally desirable for an engineer to place all the cars in a train in either a tension mode, or in a compression mode to reduce impact forces on couplers and draft gears due to relative motion of coupled cars. To place a train in a compression mode, as for example, prior to descending a grade, an engineer may retard the locomotive using the independent brake system so that the line of cars compresses against the locomotive.
The EPIC
a
3102 Braking system uses transducers to measure the pressure in the independent application and release line. Difficulty has been experienced during winter weather conditions due to freezing of moisture in the independent application and release line. The transducers which measure pressure in the independent application and release line may freeze, or the fluid pathways to the transducers may become blocked with ice. Accordingly, it is necessary to remove condensed moisture from the independent application and release line. The independent application and release line may also have other fluid contaminants such as oil droplets and it is also desirable to purge these from the system.
SUMMARY OF THE INVENTION
In one aspect, the present invention is a purge valve for expelling a liquid contaminant from a fluid conduit which is normally unpressurized but is at times pressurized with a gas which contains the liquid contaminant. The valve has a housing, a diaphragm mounted within the housing, a control chamber on a first side of the diaphragm, an exhaust passage on a second side of the diaphragm and a valve seat surrounding an upstream end of the exhaust passage. The valve seat is positioned so that the diaphragm may seal against the valve seat. A spring is placed on the second side of the diaphragm to provide a spring force on the diaphragm to press it away from the valve seat. An annular chamber is provided on the second side of the diaphragm, the annular chamber surrounding the exhaust passage. The annular chamber is open to the exhaust passage when the diaphragm is not sealed against the valve seat. The valve has a relatively low impedance flow path connected to the control chamber, the relatively low impedance flow path being for connection to the fluid conduit. The valve also has a relatively high impedance discharge flow path connected to the annular chamber and connected to receive pressure from the fluid conduit. When the valve is connected to the fluid conduit, it is open due to the spring force whenever the fluid conduit is unpressurized so that the liquid contaminant may drain from the fluid conduit through the discharge flow path to the annular chamber and thence be purged from the valve through the exhaust passage. When the fluid conduit is pressurized, a greater pressure exists in the control chamber than in the annular chamber or the exhaust passage so that the diaphragm is pressed against the valve seat and seals against the valve seat, so that the valve is closed. When pressure is first applied, for a brief time before the valve closes, contaminant liquids are forcefully expelled from the valve by the rising pressure.
In another aspect, the present invention is a purge valve arrangement for expelling a liquid contaminant from a fluid conduit which is normally unpressurized but is at times pressurized with a gas which contains the liquid contaminant. The arrangement has a liquid separator which has a relatively dry connection point and a relatively wet connection point attached to the fluid conduit. It should be understood that the terms “wet” and “dry” refer to the presence and absence of the liquid contaminant. The system also has a purge valve which has a housing and a diaphragm mounted within the housing. The valve has a control chamber on a first side of the diaphragm and an exhaust passage on a second side of the diaphragm. It has a valve seat surrounding the upstream end of the exhaust passage, the valve seat positioned so that the diaphragm may seal against the valve seat. A spring is located on the second side of the diaphragm to provide a spring force on the diaphragm to press the diaphragm away from the valve seat. An annular chamber is provided on the second side of the diaphragm, the annular chamber surrounding the exhaust passage. The annular chamber is open to the exhaust passage when the diaphragm is not sealed against the valve seat. The valve arrangement has a relatively low impedance flow path between the control chamber and the relatively dry point and it has a relatively high impedance discharge flow path between the annular chamber and the relatively wet point. The valve is open due to the spring force whenever the fluid conduit is unpressurized so that the liquid contaminant may drain from the fluid conduit through the high impedance discharge flow path to the annular chamber and thence be purged from the valve through the exhaust passage. When the fluid conduit is pressurized, a greater pressure exists in the control chamber than in the annular chamber or the exhaust passage so that the diaphragm is pressed against the valve seat and seals against the valve seat, so that the valve is closed. When pressure is first applied, for a brief time before the valve closes, contaminant liquids are forcefully expelled from the valve by the rising pressure.
OBJECTS OF THE INVENTION
It is, therefore, one of the primary objects of the present invention to provide a valve for eliminating liquid contaminants from a conduit which at times contains a pressurized gas.
Another object of the present invention is to provide a valve for a conduit which at times contains a pressurized gas, the valve being open whenever the conduit is unpressurized so that liquid contaminants may drain from the valve.
It is a further object of the present invention to provide a valve for a conduit which at times contains a pressurized gas, the valve closing whenever the conduit is pressurized to prevent loss of gas from the conduit.
It is another object of the present invention to provide a valve for a conduit which at times contains a pressurized gas, the valve remaining open for a brief time after pressure is applied so that the pressure forcefully expels contaminant liquids during the brief time and then seals to prevent further loss of pressurizing gas.
It is an additional object of the present invention to provide a valve for a conduit which at times contains a pressurized gas and which has transducers for measuring pressure, the gas being contaminated with water and the valve removes water so that t
Bostedo Robert G.
Dimsa Robert D.
Johnston Gregory L.
Santoro, Jr. Ralph
Scott Daniel G.
James Ray & Associates
Michalsky Gerald A.
Westinghouse Air Brake Company
LandOfFree
Normally open purge valve does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Normally open purge valve, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Normally open purge valve will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2500307