A system comprises the way of Quality Control to be followed during manufacturing process of Pipes, Tubes,Pipe fittings, Flanges, Fasteners, Sheets, Plates, Wires, Tube Fittings, Etc. so that an audit mechanism is introduced during manufacturing itself to produce a product meeting the requirements of desired codes & specifications.
A separate quality control department is handled by a Q.C. engineer who maintains all the records & supervises the Q.C. Inspectors.
At the raw material stage the same is checked visually for any kind of surface defects such as cracks, seams, overlapping, pitting, as well as dimensionally. A chemical & physical test is carried out before selecting the Raw material.
After acceptance of raw material a control number is issued and this is punched/marked on whole of the Raw material is to be use.
In Manufacturing Of Fittings, Flanges, etc. At the time of cutting, The control number is transferred on each cut pieces and the same is transferred after every operation of forging or forming in case of Invisibility of the same. After each forging or Forming process the material is checked visually for surface crack.
Hear treatment is carried out after final forging or forming as required by the code. After final forging or heat treatment a batch number is assigned to a lot and this batch number is stamped on each Pipes, Tubes, fittings, Flanges, Etc. and on the temperature chart which is automatically generated by temp. recorder coupled with the heating furnace. Time of final forging/forming & date is also mentioned on the chart.
After final forging/forming and Heat treatment process, all the pipe Fittings, Flanges, Fasteners, Etc. are sent for machining i.e. and preparation, O/D and I/D matching as per dimensional codes. An Expert Q.C. engineer is involved and he keeps constant vigil on every machining operation. Step machining is carried out as required by the codes. GO and NO-GO gauges are used to check the O/D & I/D of the fittings, Flanges, etc.
Tensile test is done on a sample taken from mother Raw material or from the lots of Pipes, Tubes, Fittings, Flanges, Fasteners, Etc. in accordance with codes as required by purchaser on universal testing machine which is calibrated & approved by the authorized inspection agencies.
Hardness testing is done on Atleast 10% of each lot & results are recorded in separate register.
Impact test is carried out on low temperature fittings covered by specification ASTM A420 WPL grades.
100% X-Ray examination is carried out on all Welded Pipes, Tubes, Fittings
All the Pipes, Tubes,fittings, Etc. are pickled and passivated. By pickling all the scale is removed which is formed during forging/ Forming operations. After pickling , Grinding operation is done to remove the die mark and inside / outside burrs formed during forming & machining operation. Dimensional check is carried out finally & recorded.
After the final dimensional check each fittings is stamped /marked for size, schedule, Fittings specification, Heat mark & batch number.
All the fittings supplied to the purchaser to the purchaser are furnished with Manufacturer’s test certificate. This certificate contains data i.e. Raw material composition, Heat treatment done, Heat Mark, Batch Number, Hardness value, Chemical & physical test results, Radiography results (If carried Out) , size, schedule, specification and quantity supplied.