( Div. of Sterling Tubes & Valves Pvt. Ltd. )

VARIOUS QUALITY TESTS

DIMENSION CHECK

To ensure dimensional accuracy of OD, ID, Thickness, Length, Ovality, etc.

Surface Check

To ensure that finished tubes are free from scale, pit marks rupture I.D. & O.D scores, roll marks, dent, etc.

Chemical Test

To test chemical constituents & quality parameters of raw materials & finished products.

MECHANICAL TESTS

Hardness Test

It is carried out by Rockwell I Twin Hardness Testers.(HRC, BHN Scale)

Tensile Test

It is carried out by Electronic Digital, Universal Testing Machine with Graphical Presentation.

Flaring Test

To check the ductility of material.End of tubes should be flared successfully without developing cracks.

Flange Test

This test is conducted to check the strength by subjecting to extreme compression stress. The photo besides shows a test piece subject to Flange Test as per standard.

Flattening Test

This test is conducted to check the strength by subjecting to extreme compression stress. Flattening test is to test the ultimate Steel deformation ability of seamless steel pipes under the given conditions and crush deformation without crack defects. The principle is to apply the length of the seamless steel pipe to the specified length of the end of the sample or seamless steel pipes

Bend Test

At its most basic level a bend test is performed on a testing machine by placing a specimen on two support anvils and bending it through applied force on 1 or 2 loading anvils in order to measure its properties. Pipes are bent as per specification at 90 C. without developing cracks.

Non Destructive Test

Hydro Test (Uo To 1500 Bar):-

Hydro testing, more formally called hydrostatic testing, is a type of test that is performed on pressure vessels to check for leaks. Hydro testing involves completely filling up a pressure vessel with water and then pressurizing it. Once pressurized, leaks can be detected.100% Hydrosatic testing is carried by precision machine on all tubes.

Eddy Current Test :-

Eddy current testing is a non-destructive testing (NDT) inspection method used for a variety of purposes, including for flaw detection, material and coating thickness measurements, material identification and establishing the heat treatment condition of certain material& it is to detect subsurface inhomogeneities from inside & outside of tubes.

Utrasinic Test :-

Ultrasonic testing (UT) is a non-destructive test method that utilizes sound waves to detect cracks and defects in parts and materials. It can also be used to determine a material's thickness, such as measuring the wall thickness of a pipe.For detection OD subsurface flaws & imperfection.

Chrome Plating Layer / Thickness & Hardness Test :-

"Measuring Hard Chrome Plating Thickness"

  • Good Magnetic Thickness Testers Are Non Destructive And Excellent For Checking Hard Chrome On Steel.
  • A Relatively Cheap Hand Held Magnetic Instrument Normally Measures No Better Than A Tenth, Plus Or Minus A Tenth
  • Induction Hardening Is A Type Of Surface Hardening In Which A Metal Part Is Induction-Heated And Then Quenched. The Quenched Metal Undergoes A Martensitic Transformation, Increasing The Hardness And Brittleness Of The Part. In Induction Hardening Frequency Is High.

Quality Assurance Plan

Sr. No Operation Characteristics Type/Method of Check Ref STD. Instrument used Extend of check %
1.1 Seamless Mother Hollows
[A] Dimension Dimensional Measurement ( OD, THK ) As per Application STD. Micrometer OD & THK As per Q.S.P
[B] Surface Visual Inspection Visual Random Checking
[C] Chemical Checking Chemical check analysis As per Std. & P.O. Req. Spectrometer 01 Sample from each heat lot.
[D] Mechanical Testing Tensile Testing (Yield st., U.T.S. & % EL.) As per approved STD. U.T.M machine On Each lot basis as per QSP
[E] Color Coding Color code chart
2.1 Intermediate 100% Prod. & Q.C Dept. Heat Treatment
[A] Temperature Temp.Monitoring As per Std. & PO Req. Automatic Temp.Controller 100%
[B] Speed & Feed Qty   AC Variable Drive Automatic Temp.Controller Speed & feed checking for maintaining soaking time (Depends on OD & THK of the tube )
2.2 Intermediate Pickling % of HCL,% of Fe. Titration method Chemical Testing Lab by Titration Random Check
2.3 Coating Acidity of Phosphating both Fe% Lab. Randomly Check from Each lot
2.4 Drawing
[A] Dimensions Dimensional Measurement ( OD, Thk, Length ) As per Std. & P.O Req. Micrometer OD, Thk & Measuring tape Random Dimensions ( OD, Thk, Length ) As per Application Std. & PO Req.
[B] Surface Visual Inspection   Visual Random Checking
2.5 Soap Bath % of Fatly Acid Chemical Testing Lab. Random Check
2.6 Heat Treatment
[A] Temperature Temp. Monitoring As per Appro. Std. & P.O Req. Automatic Temp. Controller 100%
[B] Speed & Feed   Depends on Tubes OD & Thk A.C. variable Drive Speed & feed checking for maintaining socking time ( Depends on OD, THK, of the tube )
[C] Mechanical Testing Tensile Testing / Hardness Checking As per Appro. Std. & P.O Req. U.T.M. Machine / Rockwell superficial hardness tester & Rockwell hardness Tester U.T.M. Machine / Rockwell superficial hardness tester
2.7 Pickling HCL % & Fe % Lab. 100% on each lot
2.8 Straightening
[A] Dimensions Dimensional Measurement ( OD, Thk, Length ) As per Std. & P.O Req. Micrometer OD, Thk & Measuring tape Random Dimensions ( OD, Thk, Length ).
[B] Surface Visual Inspection Random Checking
2.9 End Cutting Length Checking Length check by measuring tape As per P.O Req Lab. Random Checking
2.10 Hydro Testing Pressure Testing by keeping of pressure for minimum of 5 seconds. Hydrostatic test As per Std. & P.O Req. Hydrostatic test Bench 100%
2.11 Eddy Current( If applicable) Surface & sub surface condition E.T Method(Non Destructive test) ASTM –A 450/ E-309 Off line eddy current testing machine 100%
2.12 Mechanical Testing for Mechanical Properties
[A] Tensile U.T.S., Yield ST & % El As per Std. & P.O Req. U.T.M M/C Random Tensile test carried out As per Std. applicable
[B] Hardness Testing Hardness testing As per Std. & P.O Req. Rockwell superficial, Rockwell Hardness Tester Randomn Check as per applicable Std.
[C] Flaring, Flatting bend testing As per Std. & P.O Req. Randomn Check as per applicable Std.
[D] Impact Testing As per Std. & P.O Req. Impact Testing Machine Randomn Check as per applicable Std.Req.
2.13 Ultrasonic Testing( If applicable) Sub surface condition Non Destructive testing by U.T. method ASTM –E 213& P.O Req Ultrasonic testing machine 100%
2.14 Chemical Testing
Product analysis Chemical check analysis As per Std. & P.O Req. Spectrometer Random testing as per app. STD Req.
P.M.I machine Spectrometer 100%
2.14 Final Cutting Length length measurement by measuring tape As per Std. & P.O Req. Measuring Tape Random check as per application standard Req.
3.1 Visual Dimensional
[A] Dimensions Dimensional Measurement (OD, Thk, Length ) As per app. Std. Micrometer OD, Thk & measuring tape 100%
[B] Visual ( Surface ) Straightens,End cuts surface checking 100%
3.2 Identification Product marking Stenciling & testing As per app. Std. Marking M/C,marking slates 100%
4.1 Packing Product delivery condition Visual 100%
5.1 Final documents Compliance to quality system procedure, P.O. Req. & appli. TDC Req. Verification and Review As per quality system procedure & PO Req. (Material Test certi.) 100%

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