REPORT ON ROOT CAUSE ANALYSIS OF CARBON STEEL GATE VALVES SEAT LEAK WHILE SITE TESTING LTVL REF: LTVL-EDR-02 Dated.23.03.2017 CUSTOMER REF: NCR-02220-0000718, NCR-02220-0000723 & NCR-02220-0000733.

CUSTOMER REF: ARAMCO EDR Mail Dated:07.02.2017 Team Members: Karthikeyan S – JGM – Head Quality Assurance. Hari K S – Sr. DGM – Head Quality Control. Suresh J – Sr. DGM, Manufacturing. Abdul Shukkur M A – DGM, Manufacturing. Vijayarangan M - Manager, Quality Control. Sivasankaran C – Manager – Painting & Packing. Sethuraman M – Asst. Manager -Quality Assurance

CONTENTS

1.0 Background 2.0 Preliminary Analysis & Interim Containment Action(s) 2.1 Preliminary Analysis 2.2 Correction 3.0 Root Cause Analysis 3.1 Problem Description 3.2 Cause and Effect Diagram 3.3 Significant Causes 3.4 Why-Why analysis 4.0 Corrective Action

Background: During the Hydro testing of sample lot at Tecnicas Reunidas (TR) Jazan site it was reported that 88 no’s out of 579 valves tested did not meet the seat leakage criteria. This was communicated to L&T Valves Limited (LTVL) vide as a Non-conformance through NCR No.: NCR-02220-0000718, NCR-02220-0000723 and NCR-02220-0000733. Subsequently LTVL received EDR from Aramco Asia Japan KK Via email dated 07.02.2017 detail of which is given below

Valve Details: Details of the 88 nos. valves reported with seat leak at site is given below. Refer Attachment I for valves details with Tag nos.

Valve Size 2" 2" 2" 3" 6"

Class 600 300 1500 600 600

Seat Leak Qty 70 1 2 7 8

Seat Test Pressure (Barg)

112 57 281 112 112

2.0 : Preliminary Analysis taken by LTVL on receipt of the NCR / EDR :

2.1.a Verification of Internal Documents

Documents Verified pertaining to the specific valves Review remarks Attachment

Inspection test plan

Found Acceptable and No Non-conformance or observations recorded

II

Internal Valves test report specific to leak valves III

Final Inspection Report (SCN) IV

TPI( 3rd Party Inspector) witness documents - Hydro offer list V

PDI (Pre Despatch Inspection)records VI

2.1.b Verification of WIP valves

Similar size valves in WIP tested OK valves were once again pressure tested in the shop floor and found meeting the requirements.

2.1.c Site Visit & Observation LTVL deputed their service engineer in Saudi Arabia to conduct an onsite assessment of the valves and to identify correction work. Our Service Engineer visited JAZAN site on 07th February 2017 and had meeting with TR site team. He also Visited site testing facilities & activities that were going on. Service Engineer reported the following:

1. Valves were Pressure tested at site by water washing the sand accumulated on the external surface only. The internal seat surfaces were not effectively cleaned.

2. In the Hydro testing area, Valve storage area, it was observed that packing cases were open &

found with significant sand accumulation over the valves. Refer attached photos below

3. Valves are kept without end protection cap posing a threat for foreign particles to get entrapped in the sealing areas. Refer Photo below

4. In the internals of the valve especially the valve seat bore, body seat and wedge seat surface heavy ingress of sand was observed. Refer photo below.

5. In the valves which were hydro tested and accepted at site and kept in the ware house were without corrosion inhibitor plastic cover wrap or any protection. Sand particles found deposited on valves.

Further details obtained by LTVL Service Engineer at site Field testing (seat test only) was carried out by two sub-contractors,

(i) Universal Inspection company (UIC) (ii) Al Hoty company

at TR work shop facility allocated by TR. As on date 8th Feb 17 total 728 nos, valve were tested and 87 nos, valve reported to have seat leak in excess of requirements.

Subsequent to Feedback obtained from the service engineer after the site visit between 7th to 9th

Feb 17, LTVL sent an email communication dated 13th Feb 17 to TR team conveying that poor storage

and preservation of valves at site will lead to ingress of sand particles into the seat area causing scratch

mark during operation which will cause seat leakage refer attachment- VII

A Minutes of Meeting was prepared and signed between TR & LTVL on the above observations at site.

Refer Attachment VIII

Service engineer during his stay at Site apprised the local testing team to

1. perform the proper clean of the valve internal like bore, seat surfaces using water jet to remove the entrapped particles / Sand, wipe the seat surfaces clean with cloth and blow dry the valve internals before taking up for Pressure seat testing.

2. Also that valves after testing should be cleaned and dried and wrapped with plastic sheet and the ends covered by the end Protector.

Further 50 nos. of valves were tested in the presence of the service engineer adopting proper cleaning procedure and all the valves found to meet the seat leakage requirements. The 88 valves which failed the seat test at site were moved to the mod shop (AVIMCO) for rework

Action taken on failed valves: LTVL deputed service engineer to visit AVIMCO shop on 23rd Feb 2017 for dismantling, cleaning, reassembly and re-testing of these valves. As received condition of seat area

The Valve internals after jet cleaning using water to remove sand accumulation and debris.

2.2 Correction Following actions were identified to be carried out at the mod shop on the failed valves All the leaked valves shall be cleaned by water jet to remove sand accumulation and debris trapped inside the valve cavity The seat sealing surfaces shall be cleaned using WD40 and wiped with cloth Any minor scratch mark on the seat surfaces, same shall be removed by fine emery. In the event of a deep scratch further action would be necessary Status of the Valves at AVIMOC mod shop as on 24th March 17

Details Qty. Comments

No of valves dismantled 35

No of Valves cleaned & assembled 20

No of Valves Tested 8

Test valve Offered to TR QC engineer 3 TR QC

Balance valves to be cleaned 15 Awaiting TR QC confirmation for witnessing the tests

Valves that will not be dismantled but cleaned and re tested at AVIMCO

53 Awaiting for TR QC confirmation

3.0 Root cause Analysis 3.1 Problem Description

DESCRIPTION AREA DESCRIPTION DATA

WHAT

What object has the defect? Valves

What is the defect? Seat leak .

WHERE

Where specifically on the valve do you see the defect? Seat sealing location.

Where geographically is the object observed? TR Jazan site

WHEN

First seen - By the customer? When did we make the part?

Yes. Year 2017.

When seen since?

First occurrence at JAZAN site

When is the observation seen in the valve- while Testing operation (i.e. when the valve is used)?

During Site Pressure Testing.

HOW BIG

How many objects have noticed this observation? Eighty Eight (88nos)

How many/much observation(s) per object? One

3.2 CAUSE AND EFFECT DIAGRAM

MAN

MATERIALS

METHODS/PROCESSES MACHINE

PROBLEM

STATEMENT

CAUSE AND EFFECT DIAGRAM - DEFINE & VERIFY ROOT CAUSE

Seat leakage

observed

during Site

testing

Damage on Body/ disc

seat surface

Inadequate competency of

tester

Sand particles entrapped in

seat. Improper cleaning of

seat surfaces

Sear

In correct disc

dimension.

Excess clamping

pressure Poor Surface Finish in

body & seat

Inadequate competency

of assembler

Stem guide plate &

support plate loosening

3.3 Significant Causes – Seat Leak

Sl. No

CAUSES SIGNIFICANT / IN-SIGNIFICANT

1 Poor Surface Finish in body & seat INSIGNIFICANT

2 Stem guide plate & support plate loosening INSIGNIFICANT

3 Excess clamping pressure INSIGNIFICANT

4 In correct disc dimension. INSIGNIFICANT

5 Inadequate competency of tester INSIGNIFICANT

6 Inadequate competency of assembler INSIGNIFICANT

7 Sand particles entrapped in seat surface & improper Cleaning of seat surfaces causing seat damage

SIGNIFICANT

8 Damage on Body/ disc seat surface INSIGNIFICANT

3.4 Why-Why Analysis SIGNIFICANT CAUSE: Sand particles entrapped in seat surface Why? Sand particles entrapped in seat surface

Why? Valve storage area and packing cases were found with significant sand accumulation.

Why? Improper valve preservation & storage.

SIGNIFICANT CAUSE: Improper cleaning of seat surface Why? Rust preventive Gel in seat surface not removed

Why? No proper cleaning activity was carried out prior to Pressure testing

Root Cause: In our opinion, based on site visit by our Service engineer, observation of the valve storage & preservation, observation of dismantled valves at Mod shop and based on the root cause analysis carried out, the underlying cause for the valve leakage is improper valve preservation and storage leading to ingress of sand & foreign particles causing damage on the sealing surfaces leading to leakage. Corrective Action (at Site)

1. All the valves shall be stored properly with end Protectors in Place

2. Prior to Site Pressure testing, all the valves seat surfaces and internal shall be cleaned thoroughly to remove the rust preventive gel, dust or any other foreign particles.

3. Valves after pressure test shall be completely dried and applied with rust preventive coating

4. All the valves shall be wrapped in plastic cover with end protectors in place after cleaning and wiping dry the internals.

5. Refer LTVL Instruction & Operation Manual for storage and handling of valves at site.

Implementation of the above at site will ensure smooth operation of the valve at site

= End of Report =