The plates are to be unloaded from the truck by using hook and sling by hydra crane or ganetry of suitable capacity.
The plates will be placed to the ground level with proper wooden packing.
The plate to be cut will be given levelled packing at least 100mm above the lot so that the cutting chips will not come and contact bottom plates.
The cut size of the plate will be exactly marked and diagonal will be checked correctly. Chalk marking and all corners of the marking will be centre punched.
The pug cutting rails should be set along the marking with the help of a‘T’gauge.
Set the angle of pug cutting way to the desired bevel normally 30 degree a template can be made for checking during and after cutting.
Start cutting with“NEUTRALFLAME”and ensure smooth cutting of plate.
The bevel cutting will be done wherever the necessary side of the plates.
After cutting the burs and unusual materials will be removed by theAG7Grinding machine.
Then it may lift and to be shift to the rolling yard.
Make stitch weld abutted side and pull the shell out after opening the swing arm.
Set the plate exactly perpendicular to the roller and feed the plate inside the roller.
Make pre pinching according to the template to the diameter of pipe.The pre pinching will be done accordingly of the both sides of plate.
Start rolling with appropriate pressure throughout forward and reverse till two side of plate come in to contact.
Check theIDof shell with template and measuring tap so that we can bring accurate dimensions.
Now the rolled shell can carry to the fit up yard.
The independent shells will be kept on the fit up bed (i.e.Bed made of rails)
AllLongitudinalSeam (L.S) will be kept proper staggered 180 degree (at least above 90Degree)
Do fit up by usingLand wedge and uniform root gap as per the client instruction will be maintained.
According to length of pipe the shells will made the fit up.
Then the pipe will be rolled to saw welding bed with the help of hydraulic power pack.
The pipe will be placed over the saw welding rollers smoothly and ratedRPMwill be set on rollers for circumference joint.
Give proper earth connection and make saw welding outer and inner with suitable wire and amps
Check the welding after removal of slag and avoid puncture of welding.
Set a start plate for starting weld joint and check the finishing of welding.
After the completion of welding the pipe will be rolled out and if any repair it is to be touch up and grinding to be done repair yard.
After fabrication the pipes 5MTRor 6MTRwill be tested by filling and pressurizing of water inside the pipe to ensure the pressure withstanding of bare pipe.
For this test a hydro test machine along with mandrel installed with main supports.
Atrolley will carry the pipe and pulled and forced over the mandrel.
65 mm square rubber ring will be set along inside the pipe of two sides.
Now a moveable dummy will be fixed other end of the pipe face by trolley movement then it will be locked by bolt nut or wedge system.
Now water will be pumped inside the pipe and pressure also applied as per the specification.
After observing 5 seconds if there is no leak in welding, the pressure may be released and pipe will be taken out from theHTmachine
It is the self-lock system by rubber rings, so that quantity of water and time will be saved in this system.
Pipe both side will be provided spider using‘L’angle as per the client recommendations.
After spider fixing it is to be loaded using proper hook and sling to other operation.
Ensure any painting or in lining to be done.
Set a start plate for starting weld joint and check the finishing of welding.
After the completion of welding the pipe will be rolled out and if any repair it is to be touch up and grinding to be done repair yard.
The consumables like welding electrodes, saw welding wire, saw welding flux as per the standard and client instructions.
The quality assurance and the fabrication record and pipe number are to be maintained The inspection like UT, DPT and RT will be done as per the client instruction.
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