Flanged joints are the most common type of rigid joints, which are available with single flange or double flanges with optional puddle flange.
SPL manufactures DI flanged pipes as per clause 6.2 of IS 8329:2009 with following types of joints:
Flanges are pre-heated to around 600oC and shrink fit to the pipes after ensuring perpendicularity and holes alignment. The flanges are then welded to the pipes using automatic MIG welding under argon atmosphere and high nickel containing wire. This automatic process ensures uniform weld bead all around the circumference.
Threading of pipes and flanges are done in lathes fitted with special attachments. Using jigs and fixtures it is ensured that the bolt hole circle of the flange is concentric with the bore of the pipe and the holes of the flanges at the two ends are correctly aligned. A sealing compound suitable for use with raw water, potable water gas and domestic sewage is being applied to the threads. The screwing/tightening of the flanges to the pipes is done using a special purpose machine.
After tightening, all the pipes are subjected to pressure testing.
As per Amendment No.3, Feb 2014 to IS 8329:2000 "Welding on flanges will not be allowed on the screwed flange pipe"
|Size range||Flanging Methodology||Length||PN type||Class of pipe|
|DN80 to DN400||Welding / Screwing method||Upto & including 5.4m||PN 10 & PN 16||K9|
|DN450||Welding / Screwing method||Upto & including 5.5m (Welded) / 5.4m (Screwed)||PN 10 & PN 16||K9|
|DN500 to 1000||Welding method||Upto & including 5.5m||PN 10 & PN 16||K9|
|DN1100||Welding method||Upto & including 5.5m||PN 10||K9|
The pipes are supplied with inside Cement Mortar Lining with Portland Slag cement (IS 455:2015) or Portland Cement (IS 8112:2013).
Outside Metallic Zinc coating for Barrel Pipes and Zinc Rich Paint for flanges followed by Bituminous coating.
High Alumina Cement mortar lining and Epoxy Coating can be provided for specific conditions.
The technical data given in this site is for information purpose. It is subject to change without notice