GB2509304A

GB2509304A - Fabricating, Pressure Testing and Monitoring a Double Layer Hose Assembly

Info

Publication number: GB2509304A
Application number: GB1220452.5A
Authority: GB
Inventors: Stuart Grant Jones
Original assignee: Individual
Current assignee: Individual
Priority date: 2012-11-07
Filing date: 2012-11-14
Publication date: 2014-07-02
Anticipated expiration: 2032-11-14
Also published as: GB2509304B; GB201220452D0; GB201220057D0

Abstract

The invention relates to a double-layer hose with an end fitting (with a flange) sealed to one end of the hose, there being means to allow a pressure test or monitoring of the condition of the inner layer/tube 2 or outer layer/tube 3 of the double layer hose; an embodiment may also include an over-braid 5. An (inner) end of the end-fitting insert 1 is inserted into and sealed against one end of the hose. A loose flange If is externally located around insert 1. A threaded aperture/hole 1d extends from the insert outer surface 1a to its inner surface 1c, with a flat-face 1b at its outer end (the end opposite the inserted (inner) end) onto which the inner tube 2 has been externally 'flared-out' 2a. At the radial outer surface 1e of the inner end of the insert 1, the outer tube 3 and over-braid 5 are securely externally fastened by a 'swaged' ferrule 4 creating a pressure-resistant seal between outer tube 3 and radial outer surface 1e. The aperture/hole 1d is used for applying a pressure medium (eg gas or liquid) to the space between the inner and outer tubes.

Description

Fabricatjn&. pressure testin2 & monitorinE a double layer hose assembly This invention relates to an apparatus which provides the means for the pressure testing of the outer tube & the monitoring of the condition of the inner tube within a double layer heat set helically convoluted hose assembly, & a method of fabricating a double layer heat set helically convoluted hose assembly which provides the means for the pressure testing of the outer tube & the monitoring of the condition of its inner tube.

Double layer heat set helically convoluted plastic tubing, (with or without an external helical convolution supporting element), is used as a liner' in flexible hose assemblies. Typically, these duplex' hose assemblies are externally covered with over-braid, as this prevents the tubing from elongating when operating under pressure.

But for applications where their working pressure is very low they can be constructed without over-braid.

With swaged' hose assemblies; both inner, outer tubes & over-braid are externally secured at each end. Typically using external ferrules which may be hydraulically squeezed down, trapping both the tubes & over-braid between them & the internal end-fitting inserts creating pressure-resistant seals. Hoses assemblies without over-braid also have both tubes externally secured at each end, typically using external ferrules which may be hydraulically squeezed down creating pressure-resistant seals.

With flared-out' hose assemblies; the over-braid is externally securely fastened at each end. Typically using external ferrules which may be hydraulically squeezed down, trapping it between them & the end-fitting inserts; whilst both tubes pass internally through the inserts & are externally flared-out' onto their outermost flat-faces. Hoses assemblies without over-braid typically have no need for external ferrules.

With both these established methods of securing end-fitting inserts to double layered heat set helically convoluted tubing, both inner & outer tubes are either swaged' down together against the insert at each end, or externally flared-out' together onto outermost flat-face of the insert at each end.

Ideally, both inner & outer tubes should be pressure tested immediately after construction to ensure both are fit for purpose'. Testing the inner tube is straight forward using both established methods -typically both ends of the inner tube are sealed-off; & then it's pressurised from one end. Unfortunately neither of these methods allow for the pressure testing of the outer tube after its construction, as neither can offer any direct access to, & therefore any means to pressurise the space' between the inner & outer tubes.

It is an object of the present invention to overcome these problems.

According to the present invention there is provided apparatus which provides the means for the pressure testing of the outer tube, as well as the means to monitor the condition of the inner tube whilst operating, within a double layer heat set helically

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convoluted hose assembly (with or without an external helical convolution supporting element) comprising: a hollow end-fitting insert which has, a flat face at its outermost end with a larger overall diameter onto which the inner tube can be externally flared-out' & a loose' swivel flange or loose' swivel female fitting located externally around it, or, a flat face at its outermost end onto which the inner tube can be externally flared-out' which is either threaded, or has a substantially regular overall diameter along a length of its outermost outer surface a length of its outer surface at its inner end onto which the outer tube & over-braid (if required) can be securely externally fastened creating a pressure-resistant seal; & an aperture (ie; a hole) from its outer to inner surface located between the inner edge of the flat face or the inner edge of the threaded outer surface, & the end of the outer tube; whereby when end-fittings are attached at each end of a double layer hose assembly using a hollow end-fitting insert with an aperture (ie; hole) at one end & a similar insert without an aperture (hole) at the other, the outer tube & over-braid (if required) being externally securely fastened to them creating pressure-resistant seals & the inner tube externally flared-out' onto the outermost flat-faces of both inserts & the inner tube is then sealed off at both ends, the outer tube is able to be pressure tested using a suitable medium applied through the aperture, & the condition of the inner tube is subsequently able to be monitored whilst operating using a sensor directly or indirectly attached to said aperture.

According to a second aspect of the present invention there is provided a method of fabricating a double layer heat set helically convoluted hose assembly, (with or without an external helical convolution supporting element) which provides the means for the pressure testing of the outer tube & the monitoring of the condition of its inner tube whilst operating comprising the steps of: cuffing a length of double layer tubing to the desired length (if required) removing the desired length of the external helical support clement from each end; deconvoluting one end of the outer tube the desired amount & then cutting it back the desired amount; selecting a hollow end-fitting insert which has either; a flat face at its outermost end with a larger overall diameter onto which the inner tube can be externally flared-out' & a loose' swivel flange or loose' swivel female fitting located externally around it, or, a flat face at its outermost end onto which the inner tube can be externally flared-out', which is either threaded or has a substantially regular overall diameter along a length of its outermost outer surface; a length of its outer surface at its inner end onto which the outer tube & over-braid (if required) can be securely externally fastened a.

creating a pressure-resistant seal; & an aperture (ie; a hole) from its outer to inner surface located between the inner edge of the flat face or the inner edge of the threaded outer surface & the end of the outer tube; locating said end-fitting insert externally over the inner tube so that the tube extends the desired length beyond the outermost flat-face of the insert, & its outer surface at the inner end is located the desired distance within the outer tube; (if required) externally applying the desired length of over-braid onto the outer tubing from the other end; securely fastening the outer tube (& over-braid) to the insert creating a pressure-resistant seal; (itlas required) sliding external loose' flange(s) or/& swivel female(s) fitting(s) along the outer tubing (& over-braid); deconvoluting the other end of the outer tube the desired length & cuffing it back to the desired length; locating a second end-fitting insert similar to the first, but without an aperture (ie; hole), over the inner tube in a similar maimer to the first; securely fastening the outer tube (& over-braid) to the second insert in a similar manner to the first; externally flaring-out' the inner tube onto both flat-faced inserts; whereby when the inner tube is then sealed off at both ends, the outer tube is able to be pressure tested using a suitable medium applied through the aperture, & the condition of the inner tube is subsequently able to be monitored whilst operating using a sensor directly or indirectly attached to said aperture.

When a failure of the inner tube occurs within a duplex' hose assembly the contents are safely contained & conveyed by the outer tube until a replacement is fitted Nevertheless, monitoring the condition of the inner tube during its operation is important because as soon as it fails, or is about to fail, personnel need to be alerted immediately so a replacement hose assembly can be fitted as soon as possible. The condition of the inner tube is typically seen as being in one of two distinct states; it's either still working & fit for purpose', or it has failed/is about to fail & needs immediate replacement..

By being able to monitor the space' between both tubes any change in the condition of the inner tube is immediately measured by one (or more sensors) directly or indirectly attached to the aperture(s) between the outer & inner surfaces. When the hose assembly is operating normally the pressure measured in the space' between both tubes is typically relatively stable. But a failure in the inner tube typically results in an immediate 8c significant change in pressure within this space' which sensors can easily measure. Information from the sensors can be sent remotely to personnel at

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other locations, to ensure prompt action is taken to replace the hose assembly if the inner tube fails.

Suitable sensors typically monitor & measure parameters such as; pressures, flow-rates, flow patterns & temperatures. Pressure transducers are commonly used to monitor both absolute & differential pressure changes.

Typical steps involved in fabricating a duplex' double layer hose assembly are; (a) cut a length of double layer tubing to a desired length & (if required), remove desired length of the external helical support element from each end (b) deconvolute one end of the outer tube desired length & cut it back desired length (c) fit an end-fitting insert (with an aperture[ie; hole]) externally over the inner tube so that it extends the desired length beyond its outermost flat-face, & its inner end is the desired length within the outer tube (d) (if required) externally apply the desired length of over-braid onto & along the outer tubing from the other end (e) securely fasten the outer tube (& over-braid) to the insert creating a pressure-resistant seal (f) (if required) slide both external ferrules along the outer tubing (& over-braid) (g) (if required) slide external loose' flange(s) or swivel female(s) fittings along the duplex' tubing (& over-braid) (h) deconvolute the desired length of remaining outer tube & cut it to the desired length (i) fit an end-fitting insert (without an aperture[ie; hole]) externally over the inner tube so that it extends the desired length beyond its outermost flat-face, & its inner end is the desired length within the outer tube (3) securely fasten the outer tube (& over-bTaid) to the insert creating a pressure-resistant seal (k) externally flare-out' the inner tube onto both flat-faced inserts (1) pressure test both inner & outer tubes (m) inspect & dispatch the assembly.

This list represents the typical steps taken in fabricate a duplex' double layer hose assembly -but it is by no means the only order in which the steps can be performed.

They may be performed in a different order, & some of the steps may not always be neccessary.

An end-fining for a double layer duplex' hose assembly is typically constructed from; a ferrule, one end of the over-braid, one end of both tubes & an end-fitting insert having a larger overall diameter flat-face at its outermost end with a loose' swivel flange or a loose' swivel female fitting located externally around it, or an end-fining insert which is threaded along a length of its outermost outer surface.

The inner tube must be flared-out' onto the flat-faces of both end-fitting inserts, the outer tube (& over-braid) externally securely attached to them at both ends & the inner tube sealed off at both ends, before the outer tube can be pressure tested.

Pressure testing of the outer tube is typically acheived by attaching a flexible hose,

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pipe or similar, to (or into) the aperture (hole) & pressurising it using a suitable medium (typically a gas or liquid, applied through said aperture (hole).

Typically, only one aperture (hole) is required in each end-fining insert, & only one end-fining insert with an aperture is needed for each hose assembly, as both the initial pressure testing of outer tube & subsequent monitoring of the inner tube, can be performed using the same aperture (hole).

However it is foreseen that each fining may have a number of apertures (holes) around its circumference which allow for more than one parameter to be monitored at a time. If any of these apertures are not being used, suitable pressure-tight plugs' need to be securely located within them -so that outer tube can be pressure tested, & subsequently to ensure that the contents are contained if the inner tube fails whilst operating.

It is also foreseen that a hose assembly may have end-fitting inserts with an aperture (hole) fitted at both ends. This configuration allows a suitable medium (such as a gas or liquid) to be circulated through the space' between the inner & outer tubes along the length of the duplex' tubing with the apertures acting as an inlet & outlet. This configuration can for example, be used to help maintain (or change) the temperature of the contents flowing through the inner tube Extra apertures at either or both ends can be used to monitor other parameters of the circulating substance -such as its pressure, temperature, & flow rate etc..

Typically, the apertures (ie; holes) in the end-fitting insert are threaded along part or all of their depth to accommodate a flexible hose assembly/pipe or similar, through which the outer tube can be pressure tested, & then subsequently accommodate a suitable sensor to monitor the condition of the inner tube whilst its operating Apertures (holes) may have continuous concave grooves running from them along the inner surface of each end-fitting insert to its innermost edge. These grooves allow any contents within the space' between both tubes to flow more easily & assist the sensor(s) in monitoring pressure changes &/or other parameters.

The hollow end-fitting inserts are typically made from a robust, chemically resistant material such as stainless-steel (eg; 31 6L) or similar. In any case the material from which they are made is carefully chosen so that it will not adversely react with the substance being conveyed within the inner tube -in the event of its failure during operation. The internal diameter through the inside of the inserts is typically greater or equal to the overall diameter of the inner tube.

The flat-faces of the end-fitting inserts are suitable for forming externally flared-out' tube ends from the inner tube. A length of the outer surface of each end-fitting insert, at its inner end is suitable for securely externally fastening to it; the outer tube & over-braid (if required), typically using a hydraulically swaged' external ferrule. The innermost end of the outer surface typically has a larger overall diameter, as this helps to prevent the outer tube (& over-braid) from sliding axially along the insert whilst its being operated under pressure, since the swaged' ferrule is trapped & unable to move.

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The end-fittings may be for example; threaded loose' threaded swivel females, threaded males (plain or hexagon), loose? swivel flanges or potentially any other type of fitting with -a suitable flat-face onto which the inner tube can be externally flared-outt & a suitable outer surface at its inner end onto which the outer tube can be securely fastened creating a pressure-resistant seal. Alternately an end-fitting insert may have a substantially regular overall diameter along a length of its outermost outer surface instead of a threaded (male) end -this is typically called an overall-diameter (OlD) stand-pipe.

The invention will now be described, by way of example, with reference to the accompanying drawings, in which: Figure 1 shows the apparatus with an end-fitting insert l,a loose flange if which is externally located aound it, a threaded aperture (ie; hole) id that extends from its outer surface la to its inner surface ic, with a flat-face lb at its outermost end onto which the inner tube 2 has been externally flared-out' 2a, & has at its an inner end an outer surface I e where both an outer tube 3, & over-braid S are securely externally fastened by a swaged' ferrule 4 creating a pressure-resistant seal between 3 & le; in accordance with the present invention.

Figure 2 shows the apparatus with an end-fitting insert 1 which is threaded along a length of it outermost outer surface lh, has an aperture (ie; hole) Id that extends from its outer surface 1 a to its inner surface 1 c, with a continuous concave groove running from id along lc to the innermost edge of 1, with a flat-face lb at its outermost end & an outer surface le at its inner end; in accordance with the present invention.

Figure 3 shows the apparatus with an end-fitting insert 1 with a flat-face lb at its outermost end & an outer surface le at its inner end with an outer surface Ia, & a loose threaded swivel female ii externally located around it; in accordance with the present invention.

NEW Figure 4 shows the apparatus with an end-fitting insert 1 which has substantially regular overall diameter along a length of it outermost outer surface 1k, has an aperture (ie; hole) ld that extends from its outer surface Ia to its inner surface Ic, with a continuous concave groove running from id along le to the innermost edge of 1, with a flat-face lb at its outermost end & an outer surface le at its inner end; in accordance with the present invention.

New Figure 5 shows an established double layer duplex' end-fitting with both tubes flared-out' onto the outer flat-face of an insert; not in accordance with the present invention.

New Figure 6 shows an established double layer duplex' end-fitting with both tubes swaged' down onto the outer surface at the inner end of an insert; not in accordance with the present invention.

Claims

CLAIMS; 1 Apparatus which provides the means for the pressure testing of the outer tube, as well as the means to monitor the condition of the inner tube whilst operating, within a double layer heat set helically convoluted hose assembly (with or without an external helical convolution supporting element) comprising: a hollow end-fitting insert which has either, a flat face at its outermost end with a larger overall diameter onto which the inner tube can be externally flared-out' & a loose' swivel flange or loose' swivel female fitting located externally around it, or, a flat face at its outermost end onto which the inner tube can be externally flared-out' which is either threaded, or has a substantially regular overall diameter along a length of its outennost outer surface; a length of its outer surface at its inner end onto which the outer tube & over-braid (if required) can be securely externally fastened creating a pressure-resistant seal; & an aperture (ie; a hole) from its outer to inner surface located between the inner edge of the flat face or the inner edge of the threaded outer surface, & the end of the outer tube; whereby when end-fittings are attached at each end of a double layer hose assembly using a hollow end-fining insert with an aperture (le; hole) at one end & a similar insert without an aperture (hole) at the other, the outer tube & over-braid (if required) being externally securely fastened to them creating pressure-resistant seals & the inner tube externally flared-out' onto the outermost flat-faces of both inserts & the inner tube is then sealed off at both ends, the outer tube is able to be pressure tested using a suitable medium applied through the aperture, & the condition of the inner tube is subsequently able to be monitored whilst operating using a sensor directly or indirectly attached to said aperture.
2. A method of fabricating a double layer heat set helically convoluted hose assembly, (with or without an external helical convolution supporting element) which provides the means for the pressure testing of the outer tube & the monitoring of the condition of its inner tube whilst operating comprising the steps of: cutting a length of double layer tubing to the desired length (if requited) removing the desired length of the external helical support element from each end; deconvoluting one end of the outer tube the desired amount & then cuffing it back the desired amount; selecting a hollow end-fitting insert which has either; a flat face at its outermost end with a larger overall diameter onto which the inner tube can be externally flared-out' & a loose' swivel flange or loose' swivel female fitting located externally around it, or, a flat face at its outermost end onto which the inner tube can be externally flared-Hout, which is either threaded or has a substantially regular overall diameter along a length of its outermost outer surface; a length of its outer surface at its inner end onto which the outer tube & over-braid (if required) can be securely externally fastened creating a pressure-resistant seal; & an aperture (ie; a hole) from its outer to inner surface located between the inner edge of the flat face or the inner edge of the threaded outer surface & the end of the outer tube; locating said end-fitting insert externally over the inner tube so that the tube extends the desired length beyond the outermost flat-face of the insert, & its outer surface at the inner end is located the desired distance within the outer tube; (if required) externally applying the desired length of over-braid onto the outer tubing from the other end; securely fastening the outer tube (& over-braid) to the insert creating a pressure-resistant seal; (iflas required) sliding external loose' flange(s) or/& swivel female(s) fining(s) along the outer tubing (& over-braid); deconvoluting the other end of the outer tube the desired length & cutting it back to the desired length; locating a second end-fitting insert similar to the first, but without an aperture (ie; hole), over the inner tube in a similar manner to the first; securely fastening the outer tube (& over-braid) to the second insert in a similar manner to the first; externally flaring-out' the inner tube onto both flat-faced inserts; whereby when the inner tube is then sealed off at both ends, the outer tube is able to be pressure tested using a suitable medium applied through the aperture, & the condition of the inner tube is subsequently able to be monitored whilst operating using a sensor directly or indirectly attached to said aperture.
3. Apparatus or method as claimed in claim 1 or 2 in which the outer tube & over-braid (if required) are fastened to an end-fitting insert using a hydraulically swaged' external ferrule.
4. Apparatus or method as claimed in claim 3 in which an end-fitting insert has an internal diameter greater than or equal to the overall diameter of the inner tube.
5. Apparatus or method as claimed in claim 4 in which the steps taken to fabricate a hose assembly are performed in a different order.
6. Apparatus or method as claimed in claim 5 in which some of the steps may not be neccesSary.
7. Apparatus or method as claimed in claim 6 in which the innennost end of an end-fitting insert has a larger overall diameter.
8. Apparatus or method as claimed in claim 7 in which the aperture (hole) in an end-fitting insert is threaded along part or all of its depth..
9. Apparatus or method as claimed in claim 8 in which an end-fitting insert has more than one aperture (hole), & those not being used have pressure-tight plugs' securely located within them.
10. Apparatus or method as claimed in claim 9 in which there are continuous concave grooves running from the aperture(s) along the inner surface of an end-fitting insert to its innermost edge.
11. Apparatus or method as claimed in claim 10 in which end-fitting inserts with an aperture (ie; hole) are fitted at both ends, with the apertures acting as an inlet & outlet, allowing a suitable medium to be circulated through the space' between the inner & outer tubes.
12. Apparatus or method as claimed in claim 11 in which an end-fitting insert is constructed from a chemically resistant material which will not adversely react with the substance being coveyed within the inner tube.
13. Apparatus or method as claimed in claim 12 in which the end-fittings are swivel females, threaded males (plain or hexagon), swivel flanges or any other type of fitting with a suitable flat-face onto which the inner tube can be externally flared-out'.
14. Apparatus which provides the means for the pressure testing of the outer tube, as well as the means to monitor the condition of the inner tube during its operation, within a double layer heat set helically convoluted duplex' hose assembly; substantially as hereinbefore described &Ior with reference to figures 1, 2, 3 & 4.
15. A method which provides the means for the pressure testing of the outer tube, as well as the means to monitor the condition of the inner tube during its operation, within a double layer heat set helically convoluted duplex' hose assembly; substantially as hereinbefore described &ior with reference to figures 1, 2, 3 & 4.