Document Z4XeryBkoZakbj12qLy3VajXO

THERMAL INSULATION OF PIPES AND VESSELS Part 1: General Principles ` ' Pan 2: Insulation of Hot Surfaces (Excluding Refractories) Part 3 (Insulation of Cold Surfaces) is under preparation E.E.U.A. Handbook No. 12 <2963) ' Publishedfor ' THH HNCINKIiRINC EOU1PMCNT USERS ASSOCIATION 20 Grosvcnor Cardens. London. S.W.I by CONSTABLE & COMPANY LTD. . LONDON, W.C.Z j Fm I hoI m . ( I ) ^ ^ ro rU h 's guide. rig id .natorU I. *ro not recom.non.lcd irhoii tt.o ci.cunU orontM t * V* ,* lo n o f I U v m I I . r U r l h . n th . following, * HOT SURFACES Y*sV*ept tDai ta f lm tltr A llo w n lii Expansion J.|,,, Over li ft |.|n. - (2) See Section lo u r (o)--payo 09 IHSUI-iTIOtf or HOT SURFACES 31 (G) Removal and re*use of insulating materials Most insulating materials with tho exception of plastic insulation * * can be readily removed from pipes and vessels. The removal of their protective coverings is usually more difficult except in the case of sheet metal. Rigid materials are most likely to lie damaged by removal, and flexible materials least likely. Plastic materials will suffer heavy damage during removal, but may i>e reconstituted; this however is not recommended. Reference should be made to Section Pour. (See page 50.) (7) Cost The cost of insulating materials though important should not be considered alone, when estimating the economics to be effected by proper insulation ofpipes or vessels. The true cost ofan insulation system includes cost of application and protection, as well as the value of heat lost during the period of service. Relevant cost calculations are given in Section Two, which also indicates (graphi cally) the effects of insulation costs and of thermal conductivity on the total cost. Material costs alone may perhaps prove a dominating factor in the casoof temporary insulation, or where the duration for which the insulation is required is short compared with its useful life. Such cases are rarp, and in general it will prove more economical to use the appropriate insulation properly applied than to apply cheap . materials. (8) tJfeallh naznfds) Inhaled dust from certain insulating materials, notably diatomite and asbestos, can cause pncumonoconiosis, though the risk is small if cutting operations are performed out-of-doors. Dust forming operations should not however be carried, out in badly ventilated situations. Some fibrous insulating materials irritate the skin when handled, though individual sensitivity to this varies greatly. Immunity to such irritation may be obtained when these materials .are handled regularly, but gloves should be worn if the irritation proves excessive. Fibrous insulating materials are not acceptable in some branches of the food industry owing to the risk of contamination. (c) Selection of Protective Coverings and Finish A protective covering of sheet- metal provides an attractive and durable fhii.Hh, b<- such n covering is neither appropriate nor economic for all forum of iiiHiilai ion. Table g/g also lists t lie forum of protect ion t hat are recommended fur individual systems of itutu in 1 ion. Further details are given in Section Two. which for each material lists the best prot-ective coverings for minimi use, ami in Section Four, which describes their application. i 1T1 A