Patent US2560296A successfully refreshed from Google Patents.
Patent US3733903A successfully refreshed from Google Patents.
US3733903A
Expired / Lapsed
US
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Differential pressure producing flow meter
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 fluid to a throat. The converging section accelerates the fluid to throat velocity in two carefully controlled phases, each of which is terminated by the formation of a vena contracta, and the throat is equipped with a tap which senses true static pressure. The flow metering device affords a discharge coefficient on the order of 0.98 and preferably has a ''''2 sigma'''' uncalibrated accuracy of + OR - 1 percent.
Inventors
- 👤 D Halmi
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-07 10:28
CPC Classifications
G; G01; G01F; G01F1/00; G01F1/05; G01F1/34; G01F1/36; G01F1/40; G01F1/44
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
173 words
A flow metering device of the differential pressure producing type including 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 opposing converging walls each of which has upstream and downstream portions which join along an edge, and the throat comprising opposing, parallel walls which join said downstream portions along edges, c. the length of the converging section being between 0.5 square root AI(0.67-0.2B) and 2.0 square root AI(0.67-0.2B), and the length of said downstream portion being between 0.3B square root AI and 1.2B square root AI, 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 d. a pressure tap in a throat wall located so as to sense true static pressure at a point where flow is attached to that wall.
Claim 2
Dependent Claim
173 words
A flow metering device of the differential pressure producing type including 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 opposing converging walls each of which has upstream and downstream portions which join along an edge, and the throat comprising opposing, parallel walls which join said downstream portions along edges, c. the length of the converging section being between 0.5 square root AI(0.67-0.2B) and 2.0 square root AI(0.67-0.2B), and the length of said downstream portion being between 0.3B square root AI and 1.2B square root AI, 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 d. a pressure tap in a throat wall located so as to sense true static pressure at a point where flow is attached to that wall.
Claim 3
Dependent Claim
18 words
A flow metering device as defined in claim 1 in which said tube is of rectangular cross section.
Claim 4
Dependent Claim
45 words
A flow metering device as defined in claim 1 in which the length of the converging section is between Square Root AI(0.67-0.2B) and 1.1 Square Root AI(0.67-0.2B) and the length of the downstream portion is between 0.6B Square Root AI and 0.6B Square Root AI.
Claim 5
Dependent Claim
45 words
A flow metering device as defined in claim 2 in which the length of the converging section is between Square Root AI(0.67-0.2B) and 1.1 Square Root AI(0.67-0.2B) and the length of the downstream portion is between 0.56B Square Root AI and 0.6B Square Root AI.
Claim 6
Dependent Claim
31 words
A flow metering device as defined in claim 4 in which the pressure tap is located in the center of one of said parallel throat walls which join said downstream portion.
Claim 7
Dependent Claim
66 words
A flow metering device as defined in claim 4 in which a. the tube also has an inlet section which is joined to the throat by said converging section and which includes opposing parallel walls which join with the upstream portions of said converging walls; and b. one of said parallel walls of the inlet section contains a pressure tap positioned to sense true static pressure.
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 |