US3829284A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Heat treatment apparatus
Assignee: Hotwork Ltd
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Filing: 1973-05-29
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Granted: 1974-08-13
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Expires: 1993-05-29
Abstract
Abstract A welded joint between two pipes is stress relieved by injecting gaseous exhaust from two gas burners at high velocity into a ring through diametrically opposed inlets. The ring has an inwardly opening annular mouth which surrounds the welded joint and is separated from the inlets by an apertured distribution ring which divides the interior of the ring into inner and outer annular enclosures. The gases are injected tangentially with respect to the ring so that they circulate around the outer enclosure and pass to the inner enclosure through the apertures in the distribution ring. Thus the hot gases are distributed evenly around the inner enclosure to heat the welded joint for stress relieving. Outlet apertures are provided in the ring for the escape of waste gases from the inner enclosure.
Inventors
- 👤 M Hemingway
- 👤 T Ward
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 19:15
CPC Classifications
C; C21; C21D; C21D9/00; C21D9/50
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
174 words
Heat treatment apparatus for heat treating a circumferentially extending welded joint between two cylindrical pipe portions, including a tubular casing which defines a circumferentially continuous channel, a perforated ring which extends from wall to wall of the channel and separates a toroidal chamber from the mouth of the channel, the toroidal chamber being defined between the perforated ring and a base of the channel, an inlet port which opens into the toroidal chamber, an outlet port formed in a wall of the channel between the perforated ring and the mouth of the channel, and a source of hot gas connected to the inlet port for injecting hot gases at high velocity through the inlet port, the apparatus being arranged so that hot gases introduced into the channel through said inlet port during use of the apparatus are distributed evenly throughout said toroidal chamber and are exhausted through the outlet port, so that the circumferentially extending surface portion including the welded joint which extends across the mouth of the channel is heated evenly and uniformly.
Claim 2
Dependent Claim
174 words
Heat treatment apparatus for heat treating a circumferentially extending welded joint between two cylindrical pipe portions, including a tubular casing which defines a circumferentially continuous channel, a perforated ring which extends from wall to wall of the channel and separates a toroidal chamber from the mouth of the channel, the toroidal chamber being defined between the perforated ring and a base of the channel, an inlet port which opens into the toroidal chamber, an outlet port formed in a wall of the channel between the perforated ring and the mouth of the channel, and a source of hot gas connected to the inlet port for injecting hot gases at high velocity through the inlet port, the apparatus being arranged so that hot gases introduced into the channel through said inlet port during use of the apparatus are distributed evenly throughout said toroidal chamber and are exhausted through the outlet port, so that the circumferentially extending surface portion including the welded joint which extends across the mouth of the channel is heated evenly and uniformly.
Claim 3
Dependent Claim
19 words
Heat treatment apparatus as claimed in claim 1, wherein the holes of the perforated ring comprise a circumferential array.
Claim 4
Dependent Claim
31 words
Heat treatment apparatus as claimed in claim 1, wherein the axis of the inlet port is tangential to a circle which has its center on the axis of the tubular casing.
Claim 5
Dependent Claim
70 words
Heat treatment apparatus as claimed in claim 3, including a tubular component for use in combination with the tubular casing during the heat treatment of the welded joint, the tubular component being located on the opposite side of the welded joint from the tubular casing so that the adjacent portions of the two pipes welded together by the welded joint are clamped between the tubular casing and the tubular component.
Claim 6
Dependent Claim
23 words
Heat treatment apparatus as claimed in claim 4, wherein the tubular component is arranged to be inserted into the interior of the pipes.
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) | 1977-08-12 | 1978-02-11 | 1978-08-13 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-08-12 | 1982-02-11 | 1982-08-13 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-08-12 | 1986-02-11 | 1986-08-13 | $7700.00 | Window Closed / Lapsed |