Specification of Ductile Iron Pipes
Socket & Spigot Pipes The pipes are classified as K7 and K9 depending upon service condition and manufacturing process. The class designation shall comprise of : a) a prefix K b) a whole number used for thickness class designation ( this is the selected coefficient depending on the service conditions) The nominal wall
thickness of pipe ‘e’ in mm shall be calculated as
a function of the nominal diameter by the following equation with
minimum of 5 mm for K=7, 6mm for K=8 and 7mm for K=12. e=k(0.5+0.001DN) where e= wall thickness in mm DN =the nominal diameter K= the whole number coefficient The whole number used for
thickness class designation with K(i.e. K7,K9 etc.) depends on service
conditions like water supply, sewerage conveyance, gas supply etc. Standard Length for Pipes :
Tolerance on standard length for socket and spigot pipes is -30 / +70 as per BSEN 545:2002. Tolerance on length of socket & spigot pipes is ±100 as per IS 8329 : 2000
Double Flanged Pipes LIL manufactures double flanged pipes with flanges either screwed or welded on ductile Iron barrel pipes of K9 class. The flanges for screwed on or welded on double flanged pipes should be of ductile iron of 420 MPa minimum tensile strength and 5% minimum elongation and maximum hardness of 250 HB. The flanges are rated as PN10, PN16, PN25 and PN40 which correspond to the pressure rating values. Nominal pressure (PN) is a numerical designation expressed buy a number which is used for reference purposes. All components of the same nominal size DN designated by same PN number have compatible mating dimensions. For screwed or welded on flange pipes, the minimum classes as per working pressure criteria are given below : Minimum Class for Ductile Iron flanged pipes
Pipe Lengths The flanged pipes are supplied as given in the table
Internal & External Protection for Pipes
& Fittings All pipes and fittings
are delivered internally & externally coated. A wide range of coating
are offered to customers for their selection.
External Protection Pipes
· Bitumen Coating · Metalic zinc with finishing layer in accordance with ISO –8179–1 · Zinc rich paint finishing layer in accordance with ISO – 8179 – 2 · Thicker metallic zinc with finishing layer Additional
protection can be provided with · Epoxy · Polyethylene sleeving · Adhesive tapes Pipe
fittings ·
Bitumen Coating ·
Epoxy Coating ·
Zinc with finishing layer Additional
protection can be provided with : ·
Adhesive tapes Internal protection for Pipes and Fittings Cement ·
Sulphate resistant
cement (including blast furnace slag cement) ·
High alumina ( calcium aluminate ) cement mortar ·
Portland cement mortar Additional seal coat can be provided as an additional protection Epoxy Bituminous paint
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