DOCUMENT STATUS : For Reference

           

           

           

           

           

A  18‐10‐2010  Issue for Reference  Ng Van Du  Krit K.  Sumeth Y. 

Rev. Date Description Prepd. Chkd. Appd.

Project :

Owner : Consultant:

                                                                                                             EPC Contractor:

Consultant: Subcontractor :

Document Title : Method Statement for Oil Flushing of The Fuel Oil Piping System

Project No : NT 2 Format : A4

Total Pages :

Designed by : Torishima Consortium Checked by :

Function Name Sign Date Function Name Sign Date

Approved Sumeth Y. 18-10-2010 SM

Checked Krit K.

18-10-2010 ME

Prepared Ng Van Du. 18-10-2010 ME

Document No : NT2-L3-M-000-21-00022 Date: 18-10-2010

Rev. A

NHON TRACH 2 - 750MW COMBINED CYCLE POWER PLANT PROJECT

PETRO VIETNAM NHON TRACH 2 POWER JOINT STOCK COMPANY

LILAMA – PVC CONSORTIUM

FICHTNER GmbH & Co.KG CONNELL WAGNER (AURECON)

TORISHIMA - AFCOLENCO - LILAMA 18 JSC.

TORISHIMA –AF COLENCO-LILAMA 18 JSC

76BUI THIXUAN,HAI BA TRUNG DISTRICT, Tel : 84-4-943 7880 HANOI, VIETNAM Fax : 84-4-943 7875/7876

Doc. No.: NT2-L3-M-000-21-00022 Page 2 of 11 Rev.A

Torishima-AF Colenco-Lilma 18 JSC

Nhon Trach 2-750MW CCPP/ Lot 3 Balance of Plant

TORISHIMA –AF COLENCO-LILAMA 18 JSC

76BUI THIXUAN,HAI BA TRUNG DISTRICT, Tel : 84-4-943 7880 HANOI, VIETNAM Fax : 84-4-943 7875/7876

Doc. No.: NT2-L3-M-000-21-00022 Page 3 of 11 Rev.A

CONTENTS

Page

1. Purpose ……………………………………………………….………4

2. Scope ….………………………………………………………………4 2.1 Pipeline Circuit No. 1 …………………………………………………4

2.2 Pipeline Circuit No. 2 …………………………………………………4

3. Basic Requirement ……………………………………………….......4

4. Safety and Precaution ………………………………………………..5 5. Preparation for Flushing …………………………………………….5 5.1 Oil Flushing Pumps ………………………………………………........5

5.2 Temporary Storage Tank …………………………………………........6

5.3 Pipeline Circuit No. 1 …………………………………………….........6 5.4 Pipeline Circuit No. 2 …………………………………………….........6

6. Flushing Media ………………………………………………………..7

7. Flushing Procedure ……………………………………………….......7 7.1 Step I – Flushing of Pipeline Circuit No. 1………………………..........8

7.2 Step II – Flushing of Pipeline Circuit No. 2 ………………………........8

8. Cleanliness Check and Acceptance Criteria …………………….......9

9. Preservation ……………………………………………………….......9

10. Documentation …………………………………………………….......9

11. Appendix ……………………………………………………………….9

TORISHIMA –AF COLENCO-LILAMA 18 JSC

76BUI THIXUAN,HAI BA TRUNG DISTRICT, Tel : 84-4-943 7880 HANOI, VIETNAM Fax : 84-4-943 7875/7876

Doc. No.: NT2-L3-M-000-21-00022 Page 4 of 11 Rev.A

1. Purpose

In order to fulfill the cleanliness requirements for rapid commissioning and trouble-free operation of the power plant, the fuel oil piping system (FOPS) shall be cleaned before commissioning. This method statement describes all activities which covers the detail of work to be carried out for oil flushing of fuel oil piping system in scope of Balance of Plant System (BOP) for Nhon Trach 2 – 750 MW Combined Cycle Power Plant Project. Special attention must be paid to clean equipment in the system. Steps must be taken to prevent foreign substances being carried forward and damaging or plugging the apparatus. This method statement shall serve as basic guideline only which at site the procedure may adapt to suit conditions, material availability, actual completion for each segment of piping in the system and actual system piping layout.

2. Scope

After the fuel oil piping system have been finished of pressure testing and pigging cleaning process and before it is put into service, oil flushing shall be performed.

The fuel oil piping system shall be cleaned by oil flushing before put into the service includes:

2.1 Pipeline Circuit No. 1

Fuel oil pipelines from terminal point TPDO-1 to fuel oil storage tank (see Appendix A).

2.2 Pipeline Circuit No. 2

Fuel oil pipelines from fuel oil storage tank to terminal point TP2r and TP2v (see Appendix B).

3. Basic Requirement

The purpose of performing an oil flush is to remove any and all foreign material from a system or component. To most efficient method of maintaining system cleanliness is to prevent entry of foreign material into system piping or components during installation. In general, manufacture and shop assembly of the components are conducted in such a way that a clean condition is guaranteed which is in compliance with the function of the component or system. The preservation and installation on site shall also be conducted with adequate care in order not to impair this clean condition.

TORISHIMA –AF COLENCO-LILAMA 18 JSC

76BUI THIXUAN,HAI BA TRUNG DISTRICT, Tel : 84-4-943 7880 HANOI, VIETNAM Fax : 84-4-943 7875/7876

Doc. No.: NT2-L3-M-000-21-00022 Page 5 of 11 Rev.A

Cleanliness during installation requires the inspection of the pipe spools for contamination, lost tools, etc. in pre-erected pipes before further erection; cleaning if necessary. After the pipe is installed, any open ends should be capped using a suitable cover. Once complete of pressure testing and pigging cleaning, the pipeline is to be air blown continuously in order to ensure all lines are dried and free of contaminants.

4. Safety and Precaution This subject is described to provide safe practices for oil flushing operations of the fuel oil piping system. - Good coordination is essential to avoid any hazards.

- Prior to oil flushing operation, work permit shall be issued and announcement is required.

- All equipment associated with oil flushing operation must be checked to assure that it in

good condition.

- The areas of temporary storage tanks and oil flushing pumps must be surrounded with barricade and warning signs shall be posted as required.

- All workers who shall work in oil flushing operation must receive a toolbox talk to good

understand the activities.

- All workers must equip with appropriate PPE during pigging operation.

- All mechanical/ integrity work shall be completed before oil flushing operation commences.

- All potential ignition sources must be eliminated.

- The necessary safety equipment must be available at the areas of temporary storage tanks

and oil flushing pumps all times e.g. fire extinguishers, breathing apparatus, etc. 5. Preparation for Flushing

5.1 Oil Flushing Pumps

Oil flushing pumps are temporary pumps that required for pumping the flushing media from the temporary storage tanks. The oil flushing pumps are end volute suction centrifugal pump type and equipped with inlet/ outlet pressure gauges for monitoring the pumps during operation. The oil flushing pumps shall be operated at two to three times the rated flow of the system in order to increase the oil flushing velocity.

TORISHIMA –AF COLENCO-LILAMA 18 JSC

76BUI THIXUAN,HAI BA TRUNG DISTRICT, Tel : 84-4-943 7880 HANOI, VIETNAM Fax : 84-4-943 7875/7876

Doc. No.: NT2-L3-M-000-21-00022 Page 6 of 11 Rev.A

5.2 Temporary Storage Tanks

Two (2) temporary storage tanks with capacity 50 m3 each are required for storage the flushing media. The temporary storage tanks are fabricated of steel with cylindrical horizontal type. Size of each tank shall be chosen on the basis of the maximum estimated flushing media consumption. The tanks fabricated equipped with inlet, outlet, vent, drain, and overflow nozzles and tank manhole and nozzles for level measurement.

5.3 Pipeline Circuit No. 1 (Refer to Appendix A)

a) Install temporary pipe connect between oil flushing pumps to the pipeline 10EGA10

BR001 at terminal point TPDO-1.

b) Install temporary pipe from the pipeline 10EGB11 BR001 before the flexible joint 10EGB11 AB001 and from the pipeline 10EGB12 BR001 before the flexible joint 10EGB12 AB001 and then connect to the temporary storage tanks.

c) Remove the permanent filter element of strainer 10EGA10 AT001 & 10EGA10

AT002 and place on a temporary screening element of 100 mesh.

d) Close the following valves: - 10EGA10 AA001 - 10EGA10 AA002, 10EGA10 AA003 - 10EGA10 AA004, 10EGA10 AA005 - 10EGA10 AA007 - 10EGA10 AA301, 10EGA10 AA302 - 10EGB05 AA301 Note: Other valves in the pipeline circuit are not specified to closing, it shall be

opened.

e) Isolate the temperature indicator 10EGB05 CT501.

5.4 Pipeline Circuit No. 2 (Refer to Appendix B)

a) Install temporary pipe from discharge of oil flushing pumps to the pipeline 10EGB10 BR001 after the flexible joint 10EGB20 AB003 and to the pipeline 10EGB20 BR001 after the flexible joint 10EGB20 AB004.

b) Install temporary pipe from the pipeline 10EGB10 BR004 before the flexible joint 10EGB10 AB003 and from the pipeline 10EGB20 BR004 before the flexible joint 10EGB20 AB002 and then connect to the temporary storage tanks.

TORISHIMA –AF COLENCO-LILAMA 18 JSC

76BUI THIXUAN,HAI BA TRUNG DISTRICT, Tel : 84-4-943 7880 HANOI, VIETNAM Fax : 84-4-943 7875/7876

Doc. No.: NT2-L3-M-000-21-00022 Page 7 of 11 Rev.A

c) Install temporary pipe connect between the pipeline 10EGC11 BR007 before valve

10EGC11 AA005 and the pipeline 10EGC11 BR002 after valve 10EGC11 AA003 in order to bypassing the simplex strainer 10EGC11 AT001 and DO forwarding pump 10EGC11 AP001.

d) Install temporary pipe connect between the pipeline 10EGC12 BR007 before valve

10EGC12 AA005 and the pipeline 10EGC12 BR002 after valve 10EGC12 AA003 in order to bypassing the simplex strainer 10EGC12 AT001 and DO forwarding pump 10EGC12 AP001.

e) Install temporary pipe connect between the pipeline 10EGC21 BR007 before valve

10EGC21 AA005 and the pipeline 10EGC21 BR002 after valve 10EGC21 AA003 in order to bypassing the simplex strainer 10EGC21 AT001 and DO forwarding pump 10EGC21 AP001.

f) Install temporary pipe connect between the pipeline 10EGC22 BR007 before valve

10EGC22 AA005 and the pipeline 10EGC22 BR002 after valve 10EGC22 AA003 in order to bypassing the simplex strainer 10EGC22 AT001 and DO forwarding pump 10EGC22 AP001.

g) Remove the permanent filter element of strainer 10EGC30 AT001 & 10EGC30

AT002 and place on a temporary screening element of 200 mesh.

h) Close the following valves:

- 10EGC11 AA001, 10EGC11 AA301 - 10EGC12 AA001, 10EGC12 AA301 - 10EGC21 AA001, 10EGC21 AA301 - 10EGC22 AA001, 10EGC22 AA301 - 10EGC13 AA001, 10EGC23 AA001 - 10EGC30 AA301 - 10EGC30 AA004, 10EGC30 AA005 - 10EGC30 AA011 - 10EGC50 AA005

Note: Other valves in the pipeline circuit are not specified to closing, it shall be

opened.

i) Isolate the temperature indicator 10EGC30 CT501. 6. Flushing Media

Fuel oil no. 2 in accordance with project specification shall be used for flushing. If possible, this flushing oil should be taken from NT1 which routes into the temporary storage tanks via a temporary flow meter.

TORISHIMA –AF COLENCO-LILAMA 18 JSC

76BUI THIXUAN,HAI BA TRUNG DISTRICT, Tel : 84-4-943 7880 HANOI, VIETNAM Fax : 84-4-943 7875/7876

Doc. No.: NT2-L3-M-000-21-00022 Page 8 of 11 Rev.A

7. Flushing Procedure

The temporary storage tanks should be filled with fuel oil about to high level. When the oil flushing pumps are turn on for filling the pipeline circuit to be flushed, oil level in the temporary storage tanks will decrease. Make-up oil need to be added to maintain oil level in the temporary storage tank is always above the suction of oil flushing pumps during oil flushing operations. The major steps for oil flushing are as follow: 7.1 Step I – Flushing of Pipeline Circuit No. 1

a) Install all temporary equipment and pipes as required.

b) Check correct positioning of valves.

c) Flush the pipeline circuit by circulating the flushing oil.

d) Check for dirt at temporary screening element at the strainer 10EGA10 AT001 &

10EGA10 AT002.

e) If too much contamination still exists in the pipeline circuit, flushing shall be repeated.

f) If cleanliness is satisfactory, the pipeline circuit shall be treated as follow:

- Draining the flushing oil from the pipeline circuit back into the temporary storage

tank until emptied. - Remove all temporary and reinstate the fuel oil piping system to its original. - Fill the piping with fuel oil to prevent corrosion.

7.2 Step II – Flushing of Pipeline Circuit No. 2

a) Install all temporary equipment and pipes as required. b) Check correct positioning of valves.

c) Flush the pipeline circuit by circulating the flushing oil.

d) Check for dirt at temporary screening element at the strainer 10EGC30 AT001 &

10EGC30 AT002.

e) If too much contamination still exists in the pipeline circuit, flushing shall be repeated.

TORISHIMA –AF COLENCO-LILAMA 18 JSC

76BUI THIXUAN,HAI BA TRUNG DISTRICT, Tel : 84-4-943 7880 HANOI, VIETNAM Fax : 84-4-943 7875/7876

Doc. No.: NT2-L3-M-000-21-00022 Page 9 of 11 Rev.A

f) If cleanliness is satisfactory, the pipeline circuit shall be treated as follow:

- Draining the flushing oil from the pipeline circuit back into the temporary storage

tank until emptied. - Remove all temporary and reinstate the fuel oil piping system to its original. - Fill the piping with fuel oil to prevent corrosion.

8. Cleanliness Check and Acceptance Criteria

To determine the cleanliness of the pipeline circuit, checks must be carried out. The evaluation of the check results is done by the involved parties. The criteria for completion of oil flushing for fuel oil piping system are the size and numbers of particles still present in the circuit: - Check of particles: No particle > 1.0 mm. should be presented in the circuit.

- Check that no foreign matters such as plastic sheets, paper and biological matter are

trapped in the circuit. 9. Preservation

In general, after the oil flushing has been completed the piping system should be made ready for normal operation as soon as possible after circuit cleaning. Pipelines completely filled with fuel oil provide wet preservation.

10. Documentation

Immediately after cleanliness check, all inspection shall be recorded and signed by the parties involved.

11. Appendix

- Appendix A: Oil Flushing of Fuel Oil Piping System – Pipeline Circuit No. 1

- Appendix B: Oil Flushing of Fuel Oil Piping System – Pipeline Circuit No. 2

TORISHIMA –AF COLENCO-LILAMA 18 JSC

76BUI THIXUAN,HAI BA TRUNG DISTRICT, Tel : 84-4-943 7880 HANOI, VIETNAM Fax : 84-4-943 7875/7876

Doc. No.: NT2-L3-M-000-21-00022 Page 10 of 11 Rev.A

Appendix A

Oil Flushing of Fuel Oil Piping System – Pipeline Circuit No. 1

TORISHIMA –AF COLENCO-LILAMA 18 JSC

76BUI THIXUAN,HAI BA TRUNG DISTRICT, Tel : 84-4-943 7880 HANOI, VIETNAM Fax : 84-4-943 7875/7876

Doc. No.: NT2-L3-M-000-21-00022 Page 11 of 11 Rev.A

Appendix B

Oil Flushing of Fuel Oil Piping System – Pipeline Circuit No. 2