& corrective action for operatability issues

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ROOT CAUSE ANALYSIS & CORRECTIVE ACTION FOR PNEUMATIC OPERATED 36”CL 150 TRUNNION MOUNTED

BALL VALVES OPERATABILITY ISSUES

Team Members:

Date:11-Jan -2016

Ref: Mail dated: 21-Dec-2015

Prepared by Approved by

S.Rajesh-Sr.Engineer QA

M. Gunasekaran –DGM QA

N Kesavan – Sr.DGM, Manufacturing

M Gunasekaran – DGM, Quality Assurance

P Sudharsanam – Asst.Manager, Design

R. Selva Kumar – Sr. Engineer, Quality Control

S. Rajesh – Sr. Engineer, Quality Assurance

H. Lakshminarayanan – Asst. Manager, Manufacturing

M. Balasubramanian – Executive, Manufacturing

Vikash kulshrestha – Manager, Servicing

M.K. Baranidharan – DGM, Quality control

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CONTENTS

1.0) Background of the complaint as received.

2.0) Preliminary Investigation done at LTVL on receipt of complaint

a. Verifications at L&T Valves Factory

3.0) Site visit and observation

4.0) Based on site observation of damaged components Correction carried out

5.0) Root Cause Analysis: To identify the underlying cause

a. Problem Description

b. Cause and Effect Diagram

c. Significant Causes

d. Why- Why analysis

6.0) Conclusion

7.0) Corrective action

8.0) List of Spares supplied

9.0) Reference Documents

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1.0 Background of the complaint as received:

Complaint Description: It was reported from CAIRN site at Barmer that large TMBV valves in size 36”class 150 - 2 No’s reported as jamming during preliminary on/off test after few cycles before start up while commissioning the valves in pipelines. Following table gives the summary of the valve details

Sl No Valve Description Valve Sl No Tag No Complaint Reported at Site

1 36” # 150 TMBV 14G701116 MPT-XSV-2542 Pneumatic actuator valve got jammed 2 36” # 150 TMBV 14G701115 MPT-XSV-2642

2.0 Preliminary Investigation done at LTVL on receipt of Complaint A) Verifications of Documents

The following documents were verified and found in order:

Shell & End connector Dimension Reports verified & found OK.

Ball Dimension Report Verified & Found OK

Seat Ring Dimension report Verified & Found OK

Stem Dimension report verified & Found OK

Stem Housing Dimension Report verified & Found OK

Bearing Block Dimension Report Verified & Found OK

Junk Ring & Gland Dimension Reports verified & OK

Hydro Test Report (VTR) Verified & Found OK

Actuator Functional Test Report Verified & Found OK

Material Test certificate verified for Pressure Bearing components & Found OK

Internal valve test report Verified & Found OK.

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Actuator Test Certificate for Pneumatic actuated Valves verified & Found OK.

Partial Stroke Test (PST) Report Verified for Pneumatic actuated Valves & found OK.

Final inspection report Verified & Found OK.

Pre Dispatch Inspection Report Verified & Found OK.

1 Valve TPI Witness done by Bureau Veritas

B) Verifications of WIP valves at shop assembly

Similar WIP valves were sampled for functional test and found having smooth operation.

Random sampling check carried from the available WIP Stem, Stem housing , Stem Bearing components of its dimension & found meeting the requirement.

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3.0 Site Visit & observation LTVL deputed his engineers from service as well as from production to do the onsite assessment and evolve correction work 1st visit by LTVL Engineers - 30th Nov 2015 o 04th Dec 2015 ( Visit by Mr. Sugumar) 2nd visit by LTVL Engineers - 13th Dec 2015 to 28th Dec 2015 (Visit by Mr. Balasubramanian) 3rd visit by LTVL Engineers - 19th Dec 2015 to 9th Jan 2016(Visit by Lakshmi Narayanan) Site Observation made by LTVL engineers as follows,

Split bearing damage

Spilt Bearing found totally damaged

Stem & Stem housing contact area severely damaged

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Photos from Site - 36” Cl 150 Valve MPT-XSV-2542 Dismantled

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4.0 Based on the site observation of damaged components following Correction carried out

1. 01 Nos. 36”#150 (3P) Tag No. 2642, Valve Serial No. 14G701115 with Rotex Pneumatic Actuators Scratches observed on stem, removed by 0.2 mm cut on stem bearing

areas; Stem housing dismantled & necessary soft spares replaced (Refer

Clause 8.0 for spare details). Valve Found operating smoothly.

Rework Details done at site

Description Bearing - Ball Bearing - Stem Gland

Tag No. Lower side

Upper side

Stem housing Bearing Gland Bearing

MPT-XSV-2642

Not removed.

Not Removed.

Scratches, 0.2 mm cut on Stem and bearing replaced.


0.2mm cut

2. 01 No. 36”#150 (3P) Tag No. 2542 Valve Serial No. 14G701116 with Rotex Pneumatic Actuators Scratches observed on stem, removed by 0.2 mm cut on stem bearing

areas & Seat ring found damaged; Valve Dismantled & Necessary soft

spares & Seat Ring replaced ( Refer Clause 8.0 for spare details).

Valve Found operating smoothly.

Rework Details at site

Description Bearing - Ball Bearing - Stem Gland

Tag No. Lower side

Upper side

Stem housing Bearing

Gland Bearing

MPT-XSV-2542

Replaced with new

one.

Replaced with new

one



0.2mm cut

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After the rework 36”cl 150 - 1 No (Tag No MPT-XSV-2542), which has been hydro seat

and pneumatic seat tested to confirm the seat Integrity as per the GAD and witnessed by LTHE & CIL Quality representatives.

Hydro Seat Test 22 bar / 5 Mins No Visual leakage

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5.0 Root Cause Analysis: To identify the underlying cause

a) Problem Description

DESCRIPTION AREA

DESCRIPTION

WHAT

What object has the defect Trunnion Mounted Ball Valve

What is the defect? Operatability Issue on the Pneumatic actuated Valves

WHERE

Where specifically on the valve do you see the defect?

On the Stem Bearing & Ball Bearing area

Where geographically is the object observed?

Cairn Site,Rajasthan

WHEN

First seen - By the customer? Yes

When seen since? Nov 2015

When is the observation seen in the valve- while testing @ site, operation (i.e. when the valve is used)?

during preliminary on/off test after few cycles before start up while commissioning the valve in pipeline

When is the observation seen in the life of the object?(eg. when new or after few years of service)

4 Months after Installed in the Pipeline

HOW BIG How many objects have noticed this observation? 36” – 2 No’s

Similar Parts

How many/much observation(s) per object 1 (Jamming of Valve)

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b) Cause & Effect Diagram:

c) Significant Causes

S No CAUSES SIGNIFICANT / IN-SIGNIFICANT

1.1 Wrong Actuator Selection IN-SIGNIFICANT

1.2 overlapping of edges of split bearing assembly SIGNIFICANT

1.3 Damage to the PTFE coated split bearing surface SIGNIFICANT

1.4 Actuator exhausts port not open while operating manual mode. (Pn. Actuator)

IN-SIGNIFICANT

1.5 Improper Seat pressing. IN-SIGNIFICANT

2.1 Inadequate surface Finish on Stem IN-SIGNIFICANT

3.MAN 4.MATERIALS

1.METHODS/PROCESSES 2.MACHINE

Operatability Issues

1.1 Wrong Actuator Selection 2.2 Geometrical Variations on the Components

2.1 Inadequate surface Finish on Stem

4.1 PMI Failure on the Components

3.4 Wrong Usage of MOC

1.2 overlapping of edges of split bearing assembly

3.1 wrong Measurement of Dimensions

3.2 Improper Open / Close Setting on actuators

1.5 improper Seat pressing.

1.4 Actuator exhausts port not open while operating manual mode. (Pn. Actuator)

1.3 Damage to the PTFE coated split bearing surface

2.3 Due to Compressed spring.(Pn. Actuator)

3.3 Due to over tightening of gland packing.

4.2 Improper Heat Treatment of Stem

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2.2 Geometrical Variations on the Components IN-SIGNIFICANT

2.3 Due to Compressed spring.(Pn. Act) IN-SIGNIFICANT

3.1 Dimension Variations on the Components IN-SIGNIFICANT

3.2 Improper Open / Close Setting on actuators IN-SIGNIFICANT

3.3 Due to over tightening of gland packing. IN-SIGNIFICANT

3.4 Wrong Usage of MOC IN-SIGNIFICANT

4.1 PMI Failure on the Components IN-SIGNIFICANT

4.2 Improper Heat Treatment of Stem IN-SIGNIFICANT

d) Why – Why Analysis

Root cause : 1 overlapping of edges of split bearing assembly

Why? Stem Bearing is a split design to facilitate easy assembly.

.

Why? Stem bearing geometrical Dimensions not measured.

Why? Since it is catalogue product from reputed manufacturer, 100 %

Dimension inspection not carried.

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Root cause : 2 Damage to the PTFE coated split bearing surface

Why? Increase in friction torque for valve operation.

Why? Entrapment of foreign particles between the bearing surfaces

Why? Foreign particles present during installation

6.0 Conclusion:

1. In our considered opinion, based on site visit by our engineer and

correction work carried out to rectify the valve operability and based on

the root cause analysis carried out, the underlying cause for the valve

failure at site found to be overlapping of edges of split bearing used in

the stem housing causing stem damage and thereby increase in Torque

for operation of the valve.

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2. Our observation at the site after dismantling of the stem assembly in

36 “ valves shows damages to the stem surface on the bearing seating

area.

3. As correction action, when the valve stem was skin cut to remove the

damages and with the replacement of new set of bearings, it was

demonstrated the valves operations was found satisfactory.

4. It is also to be noted, fine particles which entrapped in the bearing area

during installation could have damaged the PTFE layer of the split

bearing inner surface which also increased the friction hence affected

the valve operability

5. The Foreign particle which has come into our valve seat area have

damaged the seat on 1 valve (MPT-XSV-2542) which could have

affected our valve seat performance.

Basic function of a split in the Bearing :

The split in the bearing is provided in order to facilitate easy assembly of bearing into the stem housing.

The PTFE Coating given in the inner bearing surface is mainly to reduce friction

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7.0 Corrective Action:

1. Split stem bearing bore diameter shall be measured and recorded after

assembly to ensure compliance to design requirement.

2. Visual examination of split stem bearing assembly shall be performed to

ensure there is no sharp edge as well as overlap of the split edges

3. Before the valve assembly, the stem shall be inserted into the bearing

and check for free rotation to ensure smooth operation.

4. To avoid damage to the seat and also fine particle getting into the

bearing area it is recommended that the valve is stored properly with

end protector till the time of commissioning as per IOM instruction.

5. Metal Caution Tag indicating the storage condition shall be

implemented.

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8.0 List of Spares Supplied For Rectification:

Description Qty Date Dispatch Mode

O-RING ID 870 mm x 5.33 mm CS - VITON 2

30.11.2015 Sugumar R&D Hand carried

O-RING PARKER NO.6-924 - VITON 2 GASKET 36" Cl.150 1 'O' RING PARKER NO.2-364 - VITON 1 BACK-UP RING VITON PARKER 8-364 1 BODY-SEAL 36" Cl.150 1 'O' RING PARKER NO.2-357 - VITON 2 PACKING 36" Cl.150 2 BODY-SEAL CROSS SEC - 8 x 8 6 O-RING ID 1280mm x 10mm CS 2 BEARING ID 300 x OD 305 x 60 mm LONG 4 19.12.2015 Vikash Hand

carried BEARING ID155 x OD 160 x 25mm LONG 2 BEARING ID130 x OD 135 x 15mm LONG 2 19.12.2015 courier O-RING ID 870 mm x 5.33 mm CS - VITON 4

23.12.2015 courier

O-RING PARKER NO.6-924 - VITON 4 BEARING ID 300 x OD 305 x 60 mm LONG 4 THRUST WASHER 28" CL.600 TMBV 4 BEARING ID155 x OD 160 x 25mm LONG 2 'O' RING PARKER NO.2-364 - VITON 2 BACK-UP RING VITON PARKER 8-364 2 BODY-SEAL 36" Cl.150 2 'O' RING PARKER NO.2-357 - VITON 4 THRUST BEARING 36" Cl.150 2 PACKING 36" Cl.150 4 BEARING ID130 x OD 135 x 15mm LONG 2 SEAT RING 36" Cl.150 2 02.01.2016 courier

9.0 Reference Documents

I. GAD – 110002550-TM-010 Rev 1

II. QAP – M205LNT5104A-MPT-Q-ITP-0001 A2 Dt 18.06.2014

III. VTR - 110002550-40 Dt 06.11.2014

IV. Test cum warranty cert – 110002550-40 Dt 06.11.2014