WO2018015706A1

WO2018015706A1 - A deflector cover

Info

Publication number: WO2018015706A1
Application number: PCT/GB2017/000113
Authority: WO
Inventors: Matthew CHALK; Gregory NIGEL; Ashley Alvares; Robert Horne
Original assignee: Solent Composite Systems Limited
Priority date: 2016-07-19
Filing date: 2017-07-19
Publication date: 2018-01-25
Also published as: GB2552464B; GB2552464A; GB201612452D0

Abstract

A deflector cover comprises a housing, formed from fire resistant panels, which is adapted to fit around and enclose pipes, and in particular flanges of pipes that contain pressurised fluid, typically in excess of 500 Bar. In the event of failure of flange (or valve or similar device) in a pipe, pressurised fluid (which may also be flammable) is directed by a deflector (14). A frame (10) supports the housing at a predefined location and ensures the deflector is retained in a predefined orientation, so that in the event of a failure, the deflector directs the pressurised fluid, which may be escaping from the item as a jet of flame, in a preferred direction away from equipment, gangways along which evacuating personnel may escape or adjacent pipes, thereby reducing the risk of injury to personnel and the risk of escalation of a single event to a multiple event or catastrophic failure.

Description

A Deflector Cover

Field

The present invention relates to deflector covers, of the type, for example, that are employed in high pressure fluid systems. One example of a high pressure fluid system is the type that is found on oil rigs and off-shore gas and oil platforms. The invention is therefore particularly well suited to these types of applications where conditions are extreme and safety is paramount.

Background

Oil and gas rigs, production vessels and pipelines are collectively referred to as oil and gas installations. In these oil and gas installations oil, gas or gas/liquid mixtures (collectively hereinafter referred to as fluids) are pumped through pipes and conduits typically under high (in excess of 200 Bar) or very high pressures (in excess of 400 Bar). Although it will be understood that the invention may be used in applications where pressures are less than 200 Bar.

Flanges are used at junctions of pipes and fluid pathways to connect them to one another as well as to connect them to machines, plant and equipment. In particular, a flange is required to connect a riser, which may for example carry fluid to/from a valve located on a seabed, to an oil/gas installation for subsequent distribution to, or reinjection from, one or more branch pipelines or processing plant.

In very large oil/gas installations there are often multiple pipelines which are interconnected by way of arrays of pipes and interconnecting ducts. Flanges are employed in order to connect these pipes and interconnecting ducts. A gasket usually is interposed between flanges and loads are spread across the contact area of flanges by way of bolts.

By their nature a connection at a flange is prone to failure as it can be perceived as a 'weakest link' in a system. At the pressure regimes mentioned above, and mass flow rates of fluid that are typically in the region of 2 to 400 kgs^"1, or sometimes higher, failure of a flange can have disastrous consequences. Due to the internal pressures flange failure can lead to a fatality, injury of personnel or failure of an adjacent flange or damage to adjacent equipment. If a failure escalates this may lead to potentially catastrophic outcomes.

In order to safeguard against a failure of one flange that might lead to consequential injury, failure of another flange or damage to another machine, flange covers are deployed in order to resist explosive energy. Deflection of leakage arising from a failure event to a safe area or zone is considered to minimise risk of escalation and so reduce the risk of one flange failure giving rise to further damage, failure or injury. Safe deflection is particularly important if the leaking fluid is flammable and ignites to cause a jet fire.

The present invention arose in order to provide an improved deflector cover for equipment such as flanges and thereby overcome the aforementioned problems.

An object of the present invention is to provide an improved deflector cover, that is suitable for use as a flange cover, and which operates more efficiently than existing flange covers.

Summary of the Invention

According to a first aspect of the invention there is provided a deflector cover comprises: a housing formed from at least two fire resistant and flame resistant panels, each panel has cut-outs formed along at least one of its respective edges so that when the at least two panels are placed one adjacent another, an aperture is defined that fits around and encloses at least part of an item containing pressurised fluid; a frame supports the housing at a predefined location; a deflector is retained in a predefined orientation which in use is arranged to direct fluid leaking from the item in a preferred direction; and a vent blast relief panel is connected to the cover by a hinge mounting and a catch, the catch is adapted to yield under a predefined force in order to permit the directed fluid to escape from the housing in the preferred direction. Preferably the deflector is arranged such that it is oriented in a specific position and locked in that position by way of bolts, locks or other fixing means.

An advantage of the invention is that, in the event of an accidental leak of flammable fluid, or a flame or jet of flame that results from ignition of the flammable fluid, the leak, which takes the form of a jet of fluid or flame, is directed away from important plant and equipment, away from other similar covers and away from personnel, important areas or escape routes.

The deflector is supported in a housing which is adapted to fit around and enclose at least an item containing pressurised fluid; a frame supports the housing at a predefined location; and a deflector is retained in a predefined orientation, in use the deflector is arranged to direct fluid leaking from the item, in a preferred direction.

Ideally the housing comprises at least two panels each having cut-outs formed along at least one of their respective edges. An advantage of this is that when at least two panels are placed one adjacent another, an aperture is defined that fits around an exterior of a pipe or part of the item that is being enclosed.

Ideally herein the item, around which the housing is adapted to fit, has a circular cross section and at least one panel is adapted to fit around a circumferential region of the item.

Preferably the housing or panel that is adapted to fit around the item has a circular cut-out to fit around an item of a circular cross section. Ideally at least one panel is adapted to fit around a circumferential region of the item and this is preferably achieved by employing at least two panels, each of which has a semi circular aperture cut from it which is shaped and dimensioned to fit around a circumferential region of the item.

The housing may be in the form of a parallel-piped, such as a cubic or box shaped form. Alternatively the housing is in the form of a sphere or right circular cylindrical form. Ideally housings are lightweight, typically less than around 200 kg, and preferably less than 100 kg in mass, so that they may be quickly and easily installed by two installation engineers. Although larger deflector covers, of more than 200 kg, may be required for larger installations.

Gaskets are provided between an aperture and an external wall of the item in order to insulate gaps between the two.

Optionally a plurality of deflector panels may be provided between an aperture and an external wall of the item in order to insulate gaps between the aperture and pipe.

The panels from which the housing is formed are blast resistant and fire resistant and formed from a fire resistant material such as a composite material that is sold under the Registered Trade Mark ProTek®.

Panels are tough and are formed from impact resistant material which is also a fire resistant and flame resistant and which optionally has a fire resistant and/or a flame resistant coating.

Optionally a vent blast relief panel is incorporated which is retained on hinges by a weaker catch or clasp that is designed to fail at a lower force. When this occurs the vent blast relief panel bursts open and helps to direct the emergent fluid jet in a preferred direction.

The deflector is ideally fabricated from stainless steel or laminated composite materials and is rust resistant. An optional insulating backing layer may be provided so as to minimise heat transfer through the deflector.

The housing is formed from panels that are adapted to be assembled without leaving any gaps or spaces through which pressurised leaking fluid may pass.

Ideally the housing may comprise two or more panels that are adapted to be interconnected. Ideally the material is heat resistant to 1000°C, most preferably to temperatures around 1200°C and most possibly to temperatures in excess of 1400°C. Thicknesses of sheets that define the panels of heat resistant material are typically from 10mm to 100mm.

Panels have apertures formed or cut therein in order to enable panels to bolted or connected one to another.

A preferred embodiment of the invention will now be described, by way of example only, and with reference to the Figures in which:

Brief Description of Figures

Figure 1 is an overall view of the location of a deflector cover; Figure 2 is sectional view through Figure 1 ; and

Figure 3 is an exploded overall view showing a general assembly of a preferred embodiment of the inventing.

Detailed Description of Preferred Embodiment

There is a generalised requirement for a safer manner to contain failures of junctions, such as flanges, on oil and gas installations. Figures 1 and 2 show overall and sectional views of one type of deflector cover that is used on oil and gas installations.

Referring to Figure 3, there is shown in greater detail an overall perspective view of a referred embodiment of a deflector cover which comprises panels 1 to 8 which surround a deflector 14. Panels 1 and 5 and 2 and 6 have semi-circular cut-outs in order to fit around pipe work (as shown in Figures 1 and 2). Panels 1 to 8 are connected together by way of nuts, bolts and washers. Tie bars 9 are fixed to the panels 1 to 8 and connect to a rigid and robust frame 10 for supporting and retaining the deflector 14.

Panels 1 to 8 are bolted to a steel frame 10 and define a rigid, temperature resistant deflector cover which houses a deflector 14 which is in the form of a curved surface. It will be appreciated other forms or shapes of deflector 14 may be used, for example a hemispherical or conical deflector may be fixed in position within the housing that forms the deflector cover.

A deflector seal 12 ensures that the deflector 14 is held tight against the panels and so reduces inadvertent lateral leakage of pressurised fluid. A vent panel hinge 13 connects vent panel 8 in such a manner as to enable it to be opened by the force of pressure of the leakage, whilst retaining the vent panel 8 and preventing it from being blasted from the housing.

Deflector 14 includes an anti-rotation plate 1 1 which ensures that the deflector 14 is retained and held in a permanent location and does not rotate, displace or spin under the force of a jet in the event of a failure.

Catch 15 retains the vent panel 8 against the panels 3, 5, 6 and 7. Silicone strips 16 and 17 seal the panels 1 , 2, 5 and 6 to the pipe so as to retain heat and prevent egress of flammable fluids, such as oil, from leaking from the housing and so prevents risk of flammable liquid flowing beyond the housing. This helps to contain a hazard and reduces the risk of escalations.

Retainer plate 19 has a function similar to Catch 15 described above.

Housings, panels, frame and deflectors, as well as bolts, gaskets and silicon seals are all designed to be heat resistant to temperatures in excess of 1200 °C for a time period of at least 60 minutes and in some cases more than 2 hours. This normally provides a sufficient time interval to enable remote shut-down or isolation of plant or an evacuation in the event of an emergency. The invention has been described by way of an exemplary example only and it will be appreciated that variation may be made to the embodiment described without departing from the scope of the invention.

Claims

1 . A deflector cover comprises: a housing formed from at least two fire resistant and flame resistant panels, each panel has cut-outs formed along at least one of its respective edges so that when the at least two panels are placed one adjacent another, an aperture is defined that fits around and encloses at least part of an item containing pressurised fluid; a frame supports the housing at a predefined location; a deflector is retained in a predefined orientation which in use is arranged to direct fluid leaking from the item in a preferred direction; and a vent blast relief panel is connected to the cover by a hinge mounting and a catch, the catch is adapted to yield under a predefined force in order to permit the directed fluid to escape from the housing in the preferred direction.

2. A deflector cover according to claim 1 wherein the vent blast relief panel is suspended by the hinge mounting when the catch yields, so that the vent blast panel assists to direct a jet of fluid in the preferred direction.

3. A deflector cover according to claim 1 or 2 wherein the cover is formed from a composite material and is adapted to deflect a jet fire or flame for a period of at least 20 minutes in the event that leaking fluid ignites.

4. A deflector cover according to any preceding claim wherein the item, around which the housing is adapted to fit, has a circular cross section and at least one panel is adapted to fit around a circumferential region of the item.

5. A deflector cover according to claim 4 wherein at least two panels have an aperture formed therein, each panel being adapted to fit around part of a circumferential region of the item.

6. A deflector cover according to any preceding claim wherein the housing is in a parallel-piped form.

7. A deflector cover according to any of claims 1 to 5 wherein the housing is in the form of a right circular cylinder.

8. A deflector cover according to any of claims 5 to 7 wherein gaskets are provided between the aperture and an external wall of the item in order to insulate gaps between the aperture and the external wall of the item.

9. A deflector cover according to any preceding claim wherein the deflector, or at least a portion of the deflector, has a curved surface.

10. A deflector cover according to any preceding claim wherein a locator anchors the deflector with respect to the item.

11. A deflector cover according to any preceding claim wherein panels have a fire resistant and/or a flame resistant coating.