The pipes are to be laid by suitable crane normally 3 times bigger capacity than the pipe weight ie if the pipe weight is 5Ton the crane capacity will be 15TonAt least.
The proper sling or lifting Rope are to be used to lift the pipe safely.The skilled Rigger and Crane operator are to be used for handling the pipes.The safety point of view is more important during laying of pipe.
The laying pipe will be placed in the trench after bedding i.e. spreaded sand or loose soil over the trench so that the pipe completely rest over the trench ground level.The alignment and straight line of the pipe will be ensured along with fit up.
The root gap will be will be maintained 2 to 3 mm uniformly all around the pipe joint to achieve good penetration of [welding.
During fit up the L; and wedge may be used normally and lit should not damage much the parent materials of pipe.
After fit up the line will be checked by line dory.The pipe line in trench almost in center of the trench so that man can go inside the trench to do the welding and other works.
Now the joint is ready to carry out the root run, Dia 3.15 electrode will be used for this run to get good penetration.The type of electrode will be chosen as per the client instruction either 6013 or 7018.The welders are to be qualified and a test to be conducted for them before commencing the welding works.
Normally above 1 meter dia pipes will have the inside V so that the root run will be done inside and fill up also will be done depends up on the thickness of pipe.After completion of fill up and capping the welding we have to go for back chipping by means of grinding.
Two Engine mounted Concrete mixture will be placed both end to mix the cement and sand and the water facility also [to be arranged near the machine by pump
After Back chipping by grinding if necessary we have to do the DPcheck and ensure no slag and flaw in the welding.After visible inspection the fill up may be done with proper electrode and current.
After completion for the welding we will go for the weld inspection if any DPT, UT, RTor MPTone of the nondestructive method to use the weld checking.
After completion for the welding we will go for the weld inspection if any DPT, UT, RTor MPTone of the nondestructive method to use the weld checking.
If all weld check ok we can go for joint coating outside and inside. During outside the weld mesh may be used as a strip and apply the cement mortar. For Inside the mortar to be applied directly by skilled mason. The curing also to be done for a week time or curing compound will be applied.
In some of the pipes will contain Wrapping Coating in outside, for this pipe; we have to apply the Wrapping coating material and apply Gas blow lamp to heat it for proper bonding.
ALaying register will be maintained stating Date length of pipe chain age, Location, Joint type (Butt or Fillet)Test conducted and witnessed by the client.Any bend erection or MITRE cut more than 11.25 degree it should mention in the remarks.
After pouring entire quantity of slurry both side spinning operators can level the slurry by means of a Blade connected with a Steel Rod. Now the surface become uniform and all water content will come out in this stage.
Like this the Laying activities are to be continued all man power will be used effectively by means of good supervision.The fitter, welder, Grinder, Rigger, Operators and Helpers are to have good experience so that Progress, Quality as well as safety are to maintained in good manner.
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