The scope of this Quality Assurance Programme is to manufacture pipe fittings viz; Butt welded, Socket welded, Threaded and flanges as per various national & international material and dimensional standards. The materials used for manufacture of these fittings are Carbon Steel, Alloy Steel, Stainless steel for moderate temperature, high temperature & Low temperature services. Quality Assruances Plan comprises of controls & systems to be followed during manufacture of pipe fittings and other products so that an audit mechanism is introduced during manufacture itself, finally meeting the requirements of specification.
A seperate Quality Control department functioning under the control of Quality Control Manager, maintains all the records. Engineers and inspectors checks the material at various stages of manufacture.
Before actual purchase of raw material, Quality Control Inspector checks all the material visually for surface defects. A dimension check is carried out to see if the dimensions are as per the required code. The manufacture’s test certificate is scrutinised and identified with the material. A Chemical check test is carried out on one sample from the lot to verify the authenticity of Test Certificate, or when proper test certificate or marking is not available. In case the material is acceptable, a identification number is assigned and punched on each lot of fittings/forgings.
Prior to cutting the material which may be in the form of Pipes, plates, etc, the identification number is transferred on every piece which may be cut from the parent material. After forging/forming each piece, the same is restamped if the identification number is not visible.
Heat treatment is done on all the material as per the requirement of applicable specifications.The heat tratment furnaces are fitted with probes (thermocouples) & a temperature recorder for getting an accurate record of time temperature graph for analysis. The recorder is recaliberated by E.Q.D.C. BARODA every year. A. complete record of Time-Temperature Graph, Heat Number Caliberation Certificates, etc, is maintained
Tensile test is done on samples drawn from fittings or starting material in accordance with specificafications as required by the purchaser at a subcontracted metallurgical laboratory.
Hardness testing is carried out as per requirement of purchase order and / or the specification. The results obtained are recorded & used for certification.
Impact test is done on those materials conforming to ASTM 420/A350 as required by the code. 3 samples from each batch of material are tested for their impact properties at the temperature specified by the code, grade of materials and carried out at an extenal Laboratory.
This is done incase of supplementary requirement of the purchaser, on raw materials or finished products, as called for.
As per ASTM A 262 and its practices as called for by client or parent code of manufacture.
All reducers with half or more reductions, caps, Tees are die penetrant tested within the works. Apart from die penetrant tests at regular manufacturing intervals, all the welds made by the operator on the pipe fittings are 100% X-Ray examined as required by the code and viewed on viewer. CS and AS tees are subjected to MPI and test result recorded. Other fittings also are supplied with MPI if required by ctient as supplementary test.
Machining is carried out as per the required dimensional specifications. Adequate templates, fixtures are maintained to guide the dimensions required. Calibrated measuring instruments are used for checking various dimensions. Fittings are then deburred. Threads of Screwed fittings. checked with the help of thread gauge/plug gauge. All templates fixtures & gauges are regularly checked to ascertain that they are dimensionally stable.
Shot/Sand Blasting is done on carbon steel and alloy steed fittings whereas stainless steel fittings are pickled & passivated to remove the scale and stabilize the surface. A proper concentration of solution is maintained. CS/AS Fittings are then painted for protection against corrosion.
The fittings, inspected for various dimensions are then stamped for the required specification alongwith company’s stamp.
The fittings are supplied alongwith the manufacturer’s certificate which incorporates the following details, where ever whatever applicable : a) Chemical Analysis Results b) Tensile Test Results c) Hardness Values d) Type of heat treatement e) Nomenclature f) Results of any suppliementary tests. like impact, IGC, MICRO, ultrasonic and MPI
The “quality assurance programme” as documented here is an abridged version. This programme is pursuent to achieve desired quality levels. Detailed documents and operational data maintained by manufacturer can be reviewed by customer’s engineers on request. The programme is periodically upgraded, deleted and revised due to change in technology, process improvement or revision in applicable codes.