Quality 2018-05-09T10:01:12+00:00

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Quality Assurance Systems ( Q.A.S)

Quality Assurance Systems are being followed to ISO 9001:2008 Certified, standards in achieving a high degree of efficiency in operations. Constant efforts are made for the improvement of techniques, keeping in pace with latest technology and standards (MSS-SP-117-2002) we follow.

  • Raw Material Inspection
  • In- Process Inspection
  • Dye – Penetrant Test
  • Hydraulic and Air Test
  • Helium Leak Test
  • Bellow Cyclic Test
  • Corrective & Prevention Action
  • Calibration of Equipments and Gauges
  • Customer Feed Back

Critical Test For Bellows

  • Fatigue/ Cycle Text

Cyclic Test for the bellow is carried out for testing the fatigue strength of the bellows. Minimum   10,000 cycles (i.e. to and fro Axial movement of the bellow) are carried out for each type of the bellow on a special spring rate testing fixture.

  • Helium Leak Test (On MSLD)

Bellow Seal Valves for Vacuum Services, Helium Leak test is essential. This test is carried in-house at our works whereby valves will be tested at 10-6 Torr with Helium Gas. This would only help to certify whether the valve is suitable for Vacuum and other critical application or not.

quality-assurance

Understanding Quality Requirements (U.A.R)

Quality is a must for the operation of valves in a reliable manner. The following quality requirements must be

  •  Outside & Inside leakage of valves must be prevented.
  • Operation of the valves should be easy.
  • The different parts of the valves should be replaceable.
  • Valves should be having a long life.

INSPECTION METHODS

1.The Standard of inspection is M.S.S.S.P-55.

2.The components are first recieved via the GR (Goods Receipt).

3.Then the components are gone through inspection in the foll order:

  • Raw Material
  • Semi-finished
  • In-Process
  • Finished Components
  • Final Valve Assembly

a)Raw Material Inspection Process:

  • Defects are checked.They include Cracks,Shrinkage,Extra Metal,Sand,Scalings & other defects like surface defects,cavities,etc.
  • Embossings & Letterings are checked viz. Size,Class,Foundry identification,SG name,Heat Number,etc.
  • If defects are found,then the raw material is sent back to the foundry
  • If RT (Radiography Testing) & MPI (Magnetic Particle Inspection) is specified by customer, then Foundry has to punch their respective numbers too.
  • Bar Inspection is carried out like checking for dimensions,cracks,bends,etc.If defects are found they are sent back to the foundry viz.
  • For Forgings & Castings Matl Grade,Size & Class is checked.
  • Around 20-30% inspection of the total quantity is done.

b)Semi-Finished & Finished Inspection Process:

  • After the capacity of In-house machining is full,the rest of the machining takes place via Sub-Contract
  • Around 30% inspection of the total semi-finished components is done.
  • If there is a defect during this inspection,an NC(Non-Conformance) tag is marked on it.
  • For further inspection of the NC components,the NC Committee (comprising Heads of Planning Dept,QC Dept,Production Dept,Technical Manager,
  • The NC is of 3 types viz. AOD (Accepted of Deviation),Rejected & Rework.
  • If the NC committee decides that the NC component is an AOD,then the component is used as it is.
  • If the committee decides the component is Rejected,it is not used and the matl procurement & machining process takes place again.(In this the amount is debited back to either the supplier dept or machining dept).
  • If the committee decides the component has to be Reworked,then it is either sent back to the machining sub-contract or machined in-house depending on the urgency of the component.
  • If there is No defect,then the components are tagged as Semi-finished or Accepted(depending on the requirement & discussion with NC committee).

c)In-Process Inspection:

  • Drawing is first checked.
  • All dimensions are noted in the ‘Inspection Report’.
  • Then the dimensions are checked for around 30-40% of the machined components.
  • The Inspection Report consists of the Part Name,OA number,Drwng number,etc.

importanceofdocumentation_870pxx300px1.Quotation is the starting point of the Testing Documentation

2.Quality specifications are given by the customer & are noted down by the SG QC dept.Accordingly, comments are given to the customer for the same.

3.Before the PO is issued by the customer,the QAP (Quality Assurance Plan) is given to the customer by the QC dept.The QAP is designed as per customer requirements.

4.The QAP consists of 3 stages viz. Inward Inspection,In-process Inspection & Final Inspection.

5.Only after the approval of the QAP,the PO is issued by the customer.

6.After PO is issued,then the production processes start,thereby undergoing all the 3 stages of inspection as mentioned in Inspection Methods. (which are done In-House).

7.Then,depending on the customer requirements,there will be 2 types of Final Inspection viz. In-House Inspection OR via Third Party Inspection Agencies.

a) In-House Inspection:

  • After the QAP approval,the valves are inspected by the QC dept itself.
  • Then the FIR (Field Inspection Report) is given to the client.
  • Once the FIR is approved, a Test Certificate is issued for the customer.
  • Then the valves are sent via the Dispatch dept along with the Test Certificate.

b) Third-Party Inspection Agencies (T.P.I):

  • These are agencies either hired by the customer themselves or by Inspection Agencies registered with SG.
  • Sometimes,the customer itself has an Inspection team to inspect the valves.
  • After the QAP approval from the customer,the T.P.I persons visit the works for the inspection.
  • Inspection is done based on the customer requirements.
  • If the customer has demands of N.D.T (Non-Destructive Testing) to be done,then the charges for the same are credited on the final Bill itself.
  • If the inspection has no defects according to the TPI agency,then an FIR is sent to the customer by the TPI agency.
  • Once the FIR is approved by the customer,the TPI agency sends a Release Note to the customer as well as to SG
  • Finally,after recieving the Release Note,SG prepares the Test Certificate approved by the TPI agency.
  • Then alongwith the Test Certificate, the valves are sent via the Dispatch dept.

testing_machine-300x76 Testing Procedures & Facilities(T.P.F)

 Testing Before Assembly:

  • Depending on the requirements of the customer, there are the following N.D.T (Non-Destructive Testing) facilities:

T (Radiography Testing):

  • For Forgings,it is done mostly for Gate valves in the cylinder welding area.
  • For Castings,it is done for body,bonnet & cylinder.Sometimes even for yoke & wedge also.
  • There are further 3 types of R.T depending on the areas where it is to be performed viz. a)100% area of casting

b)ANSI-B16.34/ANSI i.e critical areas(neck & seat areas)

c)% R.T depending on qty of area to be tested.

  • Radiation source is either X-ray(current) or Gamma ray(Ir-192/Co-60).For more than 50 mm thickness Co-60 is used.
  • The Rates for R.T are charged on the basis of square inch of the films.

T (Ultrasonic Testing) :

  • It involves the use of sound waves.
  • It is used for testing of raw forgings & wrought products like pipes,bars.
  • In this test,the depth of defect is properly known.
  • Rates are charged on per day basis or individual component basis.

P.I (Magnetic Particle Inspecion) :

  • It is applied to sub-surfaces.
  • Can be used only for matls with ferritic form like Carbon Steels.
  • Cannot be used for Stainless Steel.
  • It can be carried out In-House.
  • P. (Dye Penetrant Test):
  • Used only to open surfaces.
  • Working is similar to M.P.I.
  • It can be carried out In-House.

b) Testing After Assembly :

  • The testing procedures are done as per API 598 & API 6D standards.
  • The testing procedures carried out in SG are as follows:

1) Hydro-Test (Seat Test) :

  • Clean the valve thoroughly .
  • Mount the valve on fixture.
  • Connect water pipe to inlet of valve.
  • Fill the valve with water under pressure.
  • After venting out all air,close the valve.
  • Fill outlet of the valve with water.
  • Pressurise valve according to the required pressure according to the standard for required size & class.
  • Keep the valve in the pressurised condition to the required time as mentioned in the standard.
  • Check for leakage.
  • Remove valve from the fixture,clean it thoroughly by passing air.

2) Hydrostatic Test (Shell Test) :

  • Clean the valve thoroughly .
  • Mount the valve on fixture.
  • Connect water pipe to inlet of valve.
  • Fill the valve with water under pressure.
  • After venting out all air,close the valve.
  • Pressurise valve according to the required pressure according to the standard for required size & class.
  • Keep the valve in the pressurised condition to the required time as mentioned in the standard.
  • Check for leakage.
  • Remove valve from the fixture,clean it thoroughly by passing air.

3) Pneumatic Test (Seat Test) :

  • Clean the valve thoroughly .
  • Mount the valve on fixture.
  • Close valve fully & connect air pipe to inlet of valve.
  • Fill the outlet nozzle with clean water & apply pneumatic pressure at inlet of the valve.
  • Check for leakage.
  • Remove the valve from the fixture & clean thoroughly.

4) Nitrogen Test:

  • Same as Pneumatic test in operation.
  • Only difference is that,instead of air,nitrogen gas is passed.

5) Helium Leak Test:

  • There are 2 ways in which this test can be carried out viz. ‘Vaccum Method & ‘Sniffer Method’.
  • Sniffer Method is generally carried out.

6) TESTING STANDARDS

  • Testing Standards are as per API-598 & EN12266 (PART 1&2).
Body  (Hyd) 32 Kg/cm2  76 Kg/cm2
Test Pressure 150# 300#
Seat   (Hyd) 25 Kg/cm2  55 Kg/cm2
Seat   (Air) 07 Kg/cm2  07 Kg/cm2