Patent US3733901A successfully refreshed from Google Patents.
US3733901A
Expired / Lapsed
US
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Flow metering device of the pressure differential producing type
Assignee: SPX Technologies Inc
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Filing: 1972-08-09
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Granted: 1973-05-22
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Expires: 1992-08-09
Abstract
Abstract The disclosure concerns fluid flow metering devices of the differential pressure producing type comprising a tube of polygonal, preferably rectangular, cross section which defines a converging section which guides the fluid to a throat. The throat has a pressure tap located to sense true static pressure, and the converging section accelerates the fluid over a distance that is from approximately 2.7 square root AI (1-B) to approximately 3.1 square root AI (1-B), where AI is the cross sectional area of the inlet of the tube, and B is the ratio of the square roots of the cross sectional areas of the throat and the inlet. This flow metering device affords a discharge coefficient comparable to that of the classical or Herschel Venturi, and a ''''2 sigma'''' accuracy of + OR - 1 percent.
Inventors
- 👤 D Halmi
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 22:42
CPC Classifications
G; G01; G01F; G01F1/00; G01F1/05; G01F1/34; G01F1/36; G01F1/40; G01F1/44
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
133 words
A flow metering device of the differential pressure producing type comprising: a. a tube of polygonal cross section which defines a throat and a converging section for guiding fluid thereto from an inlet region of larger cross section, b. the converging section comprising at least one pair of opposed, planar, converging walls which intersect throatdefining walls, and having a length between approximately 1.4 square root AI (1-B) and approximately 5.6 square root AI (1B), where AI is the cross sectional area of the inlet region and B is the ratio of the square roots of the cross sectional areas of the throat and the inlet region; and c. a pressure tap in a throat-defining wall located so as to sense true static pressure at a point where flow is attached to that wall.
Claim 2
Dependent Claim
133 words
A flow metering device of the differential pressure producing type comprising: a. a tube of polygonal cross section which defines a throat and a converging section for guiding fluid thereto from an inlet region of larger cross section, b. the converging section comprising at least one pair of opposed, planar, converging walls which intersect throatdefining walls, and having a length between approximately 1.4 square root AI (1-B) and approximately 5.6 square root AI (1B), where AI is the cross sectional area of the inlet region and B is the ratio of the square roots of the cross sectional areas of the throat and the inlet region; and c. a pressure tap in a throat-defining wall located so as to sense true static pressure at a point where flow is attached to that wall.
Claim 3
Dependent Claim
30 words
A flow metering device as defined in claim 1 in which said pressure tap is located in the center of one said parallel, throat-defining walls which intersect the converging walls.
Claim 4
Dependent Claim
32 words
A flow metering device as defined in claim 1 in which said converging section has an axial length between approximately 2.7 Square Root AI (1-B) and approximately 3.1 Square Root AI (1-B).
Claim 5
Dependent Claim
63 words
A flow metering device as defined in claim 3 in which a. the tube also has an inlet section which is joined to the throat by said converging section and which includes parallel, planar walls which intersect said pair of converging walls; and b. one of said parallel walls of the inlet section contains another pressure tap positioned to sense true static pressure.
Claim 6
Dependent Claim
87 words
A flow metering device as defined in claim 4 in which a. said another pressure tap in the inlet section is spaced axially from the intersection of the inlet and converging walls a distance of from approximately 0.28 Square Root AI to approximately 0.56 Square Root AI and is located midway between the side edges of said wall of the inlet section; and b. the pressure tap in the throat is located in the center of one of said parallel throat-defining walls which intersect the converging walls.
Claim 7
Dependent Claim
61 words
A flow metering device as defined in claim 5 in which a. the tube also defines a diffuser at the downstream end of the throat, b. the diffuser having an axial length up to approximately 8.6 ( Square Root AI - Square Root AT), where AI and AT are the cross sectional areas of the inlet section and the throat, respectively.
Claim 8
Dependent Claim
18 words
A flow metering device as defined in claim 6 in which the tube has a rectangular cross section.
References Cited (Backward Citations)
No citation records indexed.
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1976-05-21 | 1976-11-20 | 1977-05-22 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-05-21 | 1980-11-20 | 1981-05-22 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-05-21 | 1984-11-20 | 1985-05-22 | $7700.00 | Window Closed / Lapsed |