GB2285492A

GB2285492A - Safety pressure release outlet for a gas pipe

Info

Publication number: GB2285492A
Application number: GB9422527A
Authority: GB
Inventors: John Sykes
Original assignee: PHEONIX MECHANICAL SERVICES LI
Current assignee: PHEONIX MECHANICAL SERVICES LI
Priority date: 1993-11-09
Filing date: 1994-11-08
Publication date: 1995-07-12
Also published as: GB9323086D0; GB9422527D0

Abstract

A safety pressure release outlet for a gas pipe, for example an oxygen carrying pipe 2 comprises a seating 5 formed around an aperture formed in an outer wall of the pipe 2, and an outlet nozzle 6 arranged to fit to the seating 5. The nozzle has a central passage, one end of which connects to the interior of the pipe 2, and another end which is connected to a valve 8. The nozzle 6 is formed from a spark resistant material, for example bronze or copper, for preventing explosion or ignition of the gas 10 escaping from the pipe 2. <IMAGE>

Description

SAECE:TY PRESSURE RELEASE OUTLET The present invention relates to release outlets, and in particular, although not exclusively, to a safety pressure release outlet for an oxygen carrying pipe.

Oxygen carrying pipes are conventionally made of mild steel or carbon steel. Conventional pressure release outlets of the valve type comprise a threaded seating welded to an outer surface of the pipe wall, which is threaded to accept a mild steel nozzle. A valve is conventionally fitted to an upper end of the nozzle, for gradual release of pressure.

However, with the conventional valve outlets, when oxygen is passed through a small diameter passage in the steel nozzle, overheating of the nozzle may occur if the valve is opened too quickly, thus creating spontaneous combustion of the oxygen resulting in an exothermic reaction which subsequently destroys the pipe, with possible life-threatening consequences.

Specific embodiments of the present invention aim to provide a safer release outlet than hitherto available.

According to one aspect of the present invention there is provided a release outlet for a metal gas pipe, the outlet comprising: a seating formed around an aperture in an outer wall of the pipe, and an outlet nozzle arranged to fit the seating, the nozzle having a passage therethrough, one end of which connects into the interior of the pipe, wherein the nozzle is formed of a spark resistant material.

Preferably, the nozzle is formed of a material having a higher thermal conductivity than that of the material of the pipe wall.

Preferably, the nozzle comprises copper or bronze.

Preferably, the nozzle comprises a material made to British Standard SAE 660.

Preferably, the pipe wall is made of iron or steel.

Preferably, the nozzle is arranged to fit into the seating, such that a first end of the nozzle protrudes into the aperture in the pipe wall, to present a surface around the end of the passage, which surface is substantially continuous with the inner pipe wall surface.

Preferably, the nozzle comprises a tubular grub screw, having an outer nut-shaped portion, and the seating has a threaded bore to accept the nozzle.

Preferably the seating is an annular seating.

A dimension of the aperture, eg. a diameter may be around 2-3 mm greater than the diameter of the passage.

The invention includes a valve outlet for a pipe, the valve outlet comprising a release outlet as claimed in any one of the preceding claims, and a release valve mounted onto a second end of the nozzle.

According to a second aspect of the present invention there is provided a release outlet for a metal gas pipe, the outlet comprising: an annular seating formed around an aperture in an outer wall of the pipe, and an outlet nozzle arranged to fit the annular seating, the nozzle having a passage therethrough, one end of which connects into the interior of the pipe, wherein, in use, when gas passes from the interior of the pipe through the passage, the nozzle isolates the flowing gas from the pipe wall.

The invention includes a pipe segment having a release outlet or valve outlet as described by the first or second aspects.

For a better understanding of the invention, and to show how the same may be carried into effect, reference will now be made, by way of example, to the accompanying diagrammatic drawings, in which: Referring to Figure 1 of the accompanying drawings there is shown a release outlet for an oxygen carrying pipe according to a first specific embodiment of the present invention; and Referring to Figure 2 of the accompanying drawings, there is shown a nozzle, as used in the embodiment of Figure 1 of the accompanying drawings.

Referring to Figures 1 and 2 of the accompanying drawings, an oxygen carrying pipe 1 having an outer wall 2 of carbon steel or mild steel is provided with a valve release outlet 3 comprising an aperture 4 in the pipe wall, around which is welded an annular seating 5 of mild steel or carbon steel having a threaded bore, and into which is screwed a nozzle 6, a first end 7 of the nozzle projecting into the aperture 4, and a release valve 8 mounted at a second end of the nozzle. The nozzle comprises a threaded shaft 10, in the form of a grub screw, having the central passage 9 bored therethrough, and a nut-shaped formation 12 on an outer surface of the nozzle, for tightening the nozzle into the annular seating 5. The passage 9 through the centre of the nozzle connects the interior of the pipe with the release valve 8.

The first end of the nozzle comprises a cylindrical plug 13 for fitting into the aperture 4 in the pipe wall, such that the lower surface 14 of the plug finishes flush with the internal pipe wall surface 15, when the nozzle is inserted fully into the annular seating 5.

The nozzle is manufactured from a material which is spark proof and insusceptible to heat generated from high velocity oxygen which passes through the central passage when the valve 8 is open. For example, the nozzle may be made of metal alloy, e.g. bronze. Bronze to British Standard SAE 660 is especially suitable.

As the lower surface 14 of the plug 13 is effectively continuous with the internal surface 15 of the pipe wall 2, oxygen entering the nozzle and flowing with high velocity, flows past the plug 13 which is made of the spark proof material, rather than directly past the material of the pipe wall 2. As the oxygen passes through the passage 9 in the nozzle, the oxygen is prevented from coming into contact with the pipe wall or the annular seating 5 by the nozzle.

It will be appreciated by a person skilled in the art that the size of the nozzle may be variable in diameter and length to accommodate different specifications of pipe and outlet. Preferably the diameter of the aperture 4 in the pipe wall is 2-3 mm above the diameter of the nozzle.

The above specific embodiment may negate possible accidents caused by oxygen passing across carbon steel fittings, particularly for outlets having a nominal bore of less than 50 mm.

The reader's attention is directed to all papers and documents which are filed concurrently with or previous to this specification in connection with this application and which are open to public inspection with this specification, and the contents of all such papers and documents are incorporated herein by reference.

All of the features disclosed in this specification (including any accompanying claims, abstract and drawings), and/or all of the steps of any method or process so disclosed, may be combined in any combination, except combinations where at least some of such features and/or steps are mutually exclusive.

Each feature disclosed in this specification (including any accompanying claims, abstract and drawings), may be replaced by alternative features serving the same, equivalent or similar purpose, unless expressly stated otherwise. Thus, unless expressly stated otherwise, each feature disclosed is one example only of a generic series of equivalent or similar features.

The invention is not restricted to the details of the foregoing embodiment(s). The invention extends to any novel one, or any novel combination, of the features disclosed in this specification (including any accompanying claims, abstract and drawings), or to any novel one, or any novel combination, of the steps of any method or process so disclosed.

Claims

1. A release outlet for a metal gas pipe, the outlet comprising: a seating formed around an aperture in an outer wall of the pipe, and an outlet nozzle arranged to fit the seating, the nozzle having a passage therethrough, one end of which connects into the interior of the pipe, wherein the nozzle is formed of a spark resistant material.

2. A release outlet according to claim 1, wherein the nozzle is formed of a material having a higher thermal conductivity than that of the material of the pipe wall.

3. A release outlet according to any one of the preceding claims, wherein the nozzle comprises copper or bronze.

4. A release outlet according to any one of the preceding claims, in which the nozzle comprises a material made to British Standard SAE 660.

5. A release outlet according to any one of the preceding claims, wherein the pipe wall is made of iron or steel.

6. A release outlet according to any one of the preceding claims, wherein the nozzle is arranged to fit into the seating, such that one end of the nozzle protrudes into the aperture in the pipe wall, to present a substantially continuous inner pipe wall surface around the end of the passage.

7. A release outlet according to any one of the preceding claims, wherein the nozzle comprises a tubular grub screw, having an outer nut-shaped portion, and the seating has a threaded bore to accept the nozzle.

8. A release outlet according to any one of the preceding claims, wherein the seating is substantially annular.

9. A release outlet according to any one of the preceding claims, wherein the aperture in the pipe wall is of dimension of around 2-3 mm greater than the passage of the nozzle.

10. A valve outlet for a pipe, the valve outlet comprising a release outlet as claimed in any one of the preceding claims, and a release valve mounted onto another end of the nozzle.

11. A release outlet for a metal gas pipe, the outlet comprising: an annular seating formed around an aperture in an outer wall of the pipe, and an outlet nozzle arranged to fit the annular seating, the nozzle having a passage therethrough, one end of which connects into the interior of the pipe, wherein, in use, when gas passes from the interior of the pipe through the passage, the nozzle isolates the flowing gas from the pipe wall.

12. A release outlet or nozzle substantially as herein described with reference to the accompanying drawings.

13. A pipe segment having a release outlet or nozzle as claimed herein.