EP0547739A1
Expired / Lapsed
EP
⏱️ 0.0 years remaining
Method of forming an insulating tube
Assignee: Micropore International Ltd
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Filing: 1992-08-25
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Granted: —
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Expires: 2012-08-25
Abstract
Abstract An insulating tube is made by drawing a composite tube (16) comprising an inner tube (10) and an outer tube (14) defining an annular space therebetween, the annular space containing a compressible compacted particulate microporous insulation material (12), the outer tube (14) being made of a ductile material. The composite tube (16) is drawn through one or more dies (18) so as to reduce the diameter of the outer tube (14) to a predetermined diameter while the diameter of the inner tube (10) remains substantially constant and so as to further compress and compact the particulate microporous insulation material (12) and maintain it under compressive stress. Thereafter the ends of the composite tube (16) are trimmed. The inner tube (10) can be open at the ends thereof as the composite tube (16) is drawn through the one or more dies (18).
Inventors
- 👤 John Thomas Hughes
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-10-22 23:56
CPC Classifications
B; B21; B21C; B21C37/00; B21C37/06; B21C1/00; B21C1/16; B21C1/22; F; F16; F16L; F16L59/00; F16L59/14; F16L59/143
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
120 words
A method of forming an insulating tube characterised by the steps of: providing a composite tube (16) comprising an inner tube (10) and an outer tube (14) defining an annular space therebetween, the annular space containing a compressible compacted particulate microporous insulation material (12), the outer tube (14) being made of a ductile material; drawing the composite tube (16) through one or more dies (18) so as to reduce the diameter of the outer tube (14) to a predetermined diameter while the diameter of the inner tube (10) remains substantially constant and so as to further compress and compact the particulate microporous insulation material (12) and maintain it under compressive stress; and trimming the ends of the composite tube (16).
Claim 2
Dependent Claim
33 words
A method according to claim 1, characterised in that the inner tube (10) is open at the ends thereof as the composite tube (16) is drawn through the one or more dies (18).
Claim 3
Dependent Claim
28 words
A method according to claim 1 or 2, characterised in that the outer tube (14) is made of metal, such as copper, mild steel, stainless steel or aluminium.
Claim 4
Dependent Claim
23 words
A method according to claim 1, 2 or 3, characterised in that the inner tube (10) is made of metal or plastics material.
Claim 5
Independent Claim
26 words
A method according to any preceding claim, characterised in that the particulate microporous insulation material (12) is silica aerogel, fumed silica, precipitated silica or the like.
Claim 6
Independent Claim
27 words
A method according to any preceding claim, characterised in that the particulate microporous insulation material (12) has an initial density in the range 300 to 350 kgm⁻³.
Claim 7
Independent Claim
32 words
A method according to any preceding claim, characterised in that the particulate microporous insulation material (12) is further compacted so as to increase the density by typically 20 to 30 per cent.
Claim 8
Dependent Claim
28 words
A method according to claim 7, characterised in that the particulate microporous insulation material (12) is further compacted to a density in the range 380 to 450 kgm⁻³.
Claim 9
Independent Claim
50 words
A method according to any preceding claim, characterised in that the composite tube (16) is formed by mounting a plurality of relatively short tubes of insulation material (12) on the inner tube (10), the inner tube with the tubes of insulation material thereon being inserted into the outer tube (14).
Claim 10
Independent Claim
54 words
A method according to any one of claims 1 to 8, characterised in that the composite tube (16) is formed by mounting a plurality of relatively short half-shells of insulation material (22) on the inner tube (10), the inner tube with the half-shells of insulation material thereon being inserted into the outer tube (14).
Claim 11
Independent Claim
51 words
A method according to any one of claims 1 to 8, characterised in that the composite tube (16) is formed by compacting microporous insulation material around the inner tube (10) in a hydrostatic mould, and inserting the inner tube with the microporous insulation material compacted therearound within the outer tube (14).
References Cited (Backward Citations)
FR1331028A
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US4023557A
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EP0047525A1
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JPS5987113A
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DE3327353C2
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DE3920600A1
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EP0431649A2
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