| 摘要 |
An annulus 16 of an electrically trace-heated pipe-in-pipe structure can be sealed by introducing a flowable filler material to mould a sealing mass 30 in situ. The sealing mass 30 closes a restriction 38, 40 at which the annulus 16 is narrowed radially and embeds heating elements 10 that extend generally longitudinally through the restriction. The structure comprises an inner ring 12 spaced within an outer ring 18 to define the annulus 16 between the rings. The restriction may comprise multiple bores, each of which may contain the sealing mass 30 around the heating element 10, which follows the external contour of the restriction. An insulating layer 22 may be in the annulus 16 on the outer side of the heating elements 10. The restrictions can comprise tapered surfaces which defined longitudinally opposed inclined shoulders. The flowable material may be introduced via a circumferentially extending filling channel that communicates between a port 50 in the outer ring and the restriction. |
