Root Cause Analysis-Mill exit guide LPT.pptx

Mill exit guide

1. WELSPUN PCMD ANJAR Root Cause Analysis of Mill exit side guide failure

2. Team members CH.V.S.S.Kumar -PCMD Mechanical Maint . Vishal Gupta -PCMD Mechanical Maint . Arvind Patel -PCMD Mechanical Maint . Ramayan Chaudary - PCMD Mechanical Maint .

3. Introduction The purpose of this project is to organize all information related to the failure of Mill exit side guides which affected the production of Coils since from the inception in Plate and Coil Mill. Mill exit side guide is located at the exit side of the Stackel Mill and its main function is to guide the strip / plate centre into the Mill. The non functioning of the same may lead to unguided entry into the Mill which in some times / most of the times results a cobble which is a production loss. This malfunction particularly aggravates the problems in Coil rolling because of the more length and less thickness of the product. The Exit side guide was not in operation since commissioning due to frequent Malfunction of the same. The reason for the failures found out to be the breakage of the position sensors randomly in all the 4 cylinders mounted on the guide. The moment the sensor is replaced, it had to fail within two to five slabs rolling. In this way we had lost min 20 nos. of Position transducers and also production loss. Our team had taken initiative to make the Mill exit side guides operative . It has come out with a solution to this problem and the team members have implemented the same by modifying the existing design of the all 4 hydraulic cylinders of Exit side guide so that the Position transducers wont fail in future. The above modification carried out with resources available inhouse .

4. Introduction Because of this modification, Operations are able to continue coil rolling / plate rolling with proper centering of the slab / strip by reducing the tendency of cobbles / production loss due to material shifting during rolling. Before modification, approx. 16 to 20 position transducers had been damaged each costs approx. Rs. 50,000.00 and the guide was offline. The modification which carried out successfully on 06.10.2010 and no sensor failures were reported and the guide has been functioning normal since then.

5. Definition of the Problem       What Problem(s) Mill Exit side guides not Functioning. When Date Since Commissioning of the Mill.   Time     Different, unusual, unique Different Where Facility, site Plate and Coil Mill, WCL, Anjar.   Unit, area, equipment Mill Exit side guide.       Impact to the Goals Safety Yes. There was a danger of guides and its assembly getting damaged due to this malfunction.   Environmental Nil   Cust. Service Yes. Bad shape of the Coils.   Production-Schedule Largly affected the production of Coils. Mill was unable to roll Coils particularly of thinner gauge ( 10 & 8mm)   Property, Equip, Mtls The guide assembly was badly damaged because of this reason in the year 2009 causing loss of approximately 75 lakhs .

6. Problem Investigation

7. Solution The hydraulic cylinders modified by fixing one guiding piston on the rod of the cylinder where LPT is mounted. All four cylinders modified inhouse and put in use within a week’s time.

8. THANKS