Fluid handling – Processes – With control of flow by a condition or characteristic of a...
Reexamination Certificate
1999-03-03
2001-01-09
Hepperle, Stephen M. (Department: 3753)
Fluid handling
Processes
With control of flow by a condition or characteristic of a...
C137S269000, C137S505140, C137S505460
Reexamination Certificate
active
06170507
ABSTRACT:
CROSS-REFERENCES TO RELATED APPLICATIONS
Not Applicable.
STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT
Not Applicable.
BACKGROUND OF THE INVENTION
The present invention relates generally to fluid pressure regulators, and more specifically, to pressure regulating valves convertible in the field with minimal parts replacement to separate output pressure ranges, such as those typically used in natural and LP fuel gas controls.
Applications have existed for some time for pressure regulating valves capable of regulating to either of two selected pressures. In general, these applications have been somewhat specialized, and the required volumes relatively small, thus providing little incentive for exploring nontraditional designs.
A pressure regulating valve requirement which impacts gas valve manufacturers and users results from the fact that both natural gas and gas produced from liquefied petroleum (LP) or propane are in common use as fuel gases. These gasses have different burning characteristics, and are supplied to a furnace or other burner apparatus under different pressures. Specifically, gas generated from liquefied petroleum has a faster flame front. Accordingly, it is supplied to a burner at a higher pressure, e.g., 10 inches H
2
O, which induces more oxygen entrainment. In contrast, natural gas is typically supplied to a furnace or burner at a pressure of 3.5 inches H
2
O. Accordingly, a pressure regulating gas valve for a furnace or other appliance must regulate to a higher pressure for LP gas than for natural gas.
There are various situations in which it is not known at the outset which type of fuel gas will be used, and/or in which the type of fuel gas may be changed at some point during the operating life of the furnace or other appliance. Either situation often occurs with a gas fireplace. Another common situation is in connection with new construction of a permanent fixed location dwellings. Initially natural gas may not be available because underground gas lines are not in place in the area, or because hook up to natural gas lines is delayed by frozen ground, or for other reasons.
Typical solutions in the past have been to either change out the entire gas valve at the time of conversion to a different fuel gas, or to replace certain components such as regulator springs or pressure regulator modules. Both of these solutions are undesirable for several reasons.
Although gas valves are available for operation with either natural gas or LP, an increasing need exists for a single gas valve with a simplified field selectable gas option.
The applicants have devised a design for such a valve which retains the advantageous features of prior limited purpose designs, while providing the capability of fuel type selection at the time of installation by replacement of a single simple part without disassembly of any other valve components.
BRIEF SUMMARY OF THE INVENTION
The invention is a pressure regulator having at least first and second modes of operation in each of two pressure ranges, which may correspond to pressure ranges suitable for natural and LP gas usage respectively. The pressure regulator includes a flow control means operable to vary the gas flow as a function of the extension of a regulator spring. Extension of the regulator spring may be determined by a lever assembly, which may be in turn moveable by a shaft assembly extending along an axis through an opening in the valve housing. The shaft assembly is contained within a selector assembly, and is manually adjustable along the axis relative to the flow control means. A first stop element is positionable along the axis to a user selected position, and sets the limiting position of the regulator spring and flow control means.
One of at least two spring compression caps may be chosen to bias the shaft assembly relative to the flow control means. When the first spring compression cap is assembled into its position, the shaft assembly is effectively biased toward the lever assembly, and travel of the lever assembly is limited to a first range of motion. When the second spring compression cap is assembled into its position, the shaft assembly is effectively biased away from the lever assembly, and travel of the lever assembly is limited to a second range of motion.
These and other features and advantages of the invention will become apparent from the following description of the preferred embodiments of the invention.
REFERENCES:
patent: 3180356 (1965-04-01), Galley
patent: 4265270 (1981-05-01), Satoh
patent: 4621658 (1986-11-01), Buezis et al.
patent: 4637429 (1987-01-01), Dietiker et al.
patent: 5435343 (1995-07-01), Buezis
Dalton James M.
Dietiker Paul
Nelson Marvin D.
Hepperle Stephen M.
Honeywell International , Inc.
Rubow Charles L.
LandOfFree
Gas valve with natural/LP gas conversion capability does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Gas valve with natural/LP gas conversion capability, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Gas valve with natural/LP gas conversion capability will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2539268