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Central heating pipe has insulating sleeve bound to it, to which corrugated outer sleeve is bound, corrugations having depth at least one fortieth of outer diameter of outer sleeve
Central heating pipe has insulating sleeve bound to it, to which corrugated outer sleeve is bound, corrugations having depth at least one fortieth of outer diameter of outer sleeve
Central heating pipe (10) has an insulating sleeve (20) bound to it. A corrugated outer sleeve (30) is bound to this. The corrugations have a depth which is at least one fortieth of the outer diameter of the outer sleeve.
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