Doosan Heavy Industries & Construction Co., Ltd555 Guygok-Dong, Changwon Gyeongnam, Korea

Doc. Ref : DOOSAN/NHON TRACH 2 CCPP PROJECTIssue : Feb 15, 2011Rev : Rev.0

SITE : NHON TRACH 2 PRORJECTCONTRACT : CONTRACT DESCRIPTION: HEAT RECOVERY STEAM GENERATORCLIENT : LILAMA COOPERATIONCUSTOMER : SIEMENS POWER GENERATION – GERMANYTITLE : PNEUMATIC TEST PROCEDURE

I. SCOPE

Method Statement of Pneumatic Test

II. RESPONSIBILITYSite Manager : Paeck, Ji, HyunConstruction Manager : Nam, Sang DongMechanical Manager : Moon, Kab Do

Safety Manager : Hwang, Seong Uk

III. LIST OF THE METHOD STATEMENT

NO Method Statement Remark Issued Date Rev.

1 Erection of steel structure for Site Office 05/05/ 2010 Rev.0

2 Lay – down Construction 05/05/ 2010 Rev.0

3 Mobilization and assembly of Kobelco 7250 – 2F 30/05/2010 Rev.0

4 Mobilization and assembly of Kobelco SL6000 07/06/2010 Rev.0

5 Erection procedure of Casing 09/07/2010 Rev.1

6 Erection procedure of stack 13/07/2010 Rev.1

7 Erection procedure of harp 20/07/2010 Rev.0

8 Erection procedure of Steel Structure 26/07/2010 Rev.0

9 Erection procedure of Drum 31/07/2010 Rev.0

10 Erection procedure of Piping 14/08/2010 Rev.0

11 Erection procedure of Painting 24/08/ 2010 Rev.0

12 Erection procedure of Insulation 24/08/ 2010 Rev.0

13 Field modification for Link pipe 07/09/2010 Rev.0

14 Hydrostatic test procedure 9/12/2010 Rev.0

15 Pneumatic Test Procedure 15/02/2011 Rev.0

Scope of works: Method statement of Pneumatic Test Procedure

Brief description of detailed work: Pressure test for HRSG.

Sequence of operations1 Preparation for relevant document & permit 6 2 Preparation equipment & tools 73 Pressurizing line installation 84 Pressurizing line for test 95 Recording pressure data 10ManpowerEngineer 2 Unskilled Labors 5Safety Engineer 2 OperatorSupervisor 2 First Aider in group 4Skilled Labors 2Management structure

- Visiting manager: Nam Sang Dong / Moon Kab Do- Site supervisor: Kim Soo Woong

- Safety: Hwang Seong Uk

- Out of hours contact name: Nam Sang Dong / Moon Kab Do

- Out of hour’s phone no. 09 3354 0479 / 09 0239 2146

- Who checks the work? Nam Sang Dong / Moon Kab Do

TABLE OF CONTENTS

1. PURPOSE

2. SCOPE

3. REFERENCE DOCUMENTS

4. DEFINITIONS

5. PROCEDURE

6. DOCUMENTATION

7. ATTACHMENTS

Annexure -Ⅰ: Flow Chart for Pneumatic TestingAnnexure -Ⅱ: Organization Chart for Pneumatic TestingAnnexure -Ⅲ: Pipe Work Punch ListAnnexure -Ⅳ: Weld Inspection Summary SheetAnnexure -Ⅴ: Index of Isometric DrawingsAnnexure -Ⅵ: Pressure Test CertificateAnnexure -Ⅶ: Pipe Work Re-Instatement Check ListAnnexure -Ⅷ: Mechanical Completion Check List

1.0 PURPOSE

The purpose of this Procedure is to provide controlled system for Pneumatic Testing in

order to meet project specification and requirements of reference code and standards.

2.0 SCOPE

The procedure covers minimum requirements for Pneumatic Testing of above ground and

underground pressure piping for Nhon Thach 2 CCPP Project

3.0 REFERENCE DOCUMENT

3.1 Codes & Standards:

(1) ASME B 31.1

(2) ASME SEC.V

3.2 Siemens Project Specification :

Specification of piping system for water steam cycle and auxiliary system.

4.0 DEFINITIONS

None

5.0 PROCEDURE

5.1 General

5.1.1 DOOSAN shall mark P&ID’s as per piping system to be tested and identify the piping isometrics and the equipment to be included for such test. Test pack shall be prepared incorporating marked up P&ID’s & isometrics for test limits, punch list, pressure test certificate format, Weld Inspection Summary Sheet, Pipe work Reinstatement check list format, Mechanical completion check list format, etc.

5.1.2 All pipe supports, guides and anchors shown on piping isometric shall be fitted in position.

Any additional temporary supports, if required, shall be installed before testing. All welded attachments such as pipe supports and hanger lugs etc. shall be made before pressure test.

5.1.3 Control valves, thermo wells, orifice plates, strainer baskets, filter elements, in-line instruments and all other in line components unable to withstand the test pressure or liable to damage by the test medium or by the impact of foreign matter during the flushing or purging process shall be removed and replaced with temporary spools or spacers.

5.1.4 Flanged relief valve and safety valve shall be blanked off by bolting a blind flange to the mate of the inlet flange. Screwed relief and safety valves shall be removed and replaced with caps.

5.1.5 Where a valve to serve as test block, the test pressure shall not exceed the valve seat test pressure. If the system test pressure is higher than the valve seat test pressure, the valve shall be opened and blanked or removed to allow blanking of the marking flange.

5.1.6 All valves except those covered under 5.1.4 & 5.1.5 within the system to be tested shall be in the open position.

5.1.7 Lines containing check valve shall have source of pressure upstream of the valve. If this is not possible, swing checks shall be blocked open or have the flapper removed, and ball and piston check shall have the internal parts removed. All parts removed shall be sealed in plastic bag and wired to the valve. If none of these are practical, the check valve shall be blocked off or completely removed.

5.1.8 All hand-operated valves within a test loop shall be temporarily tagged with large red “CAUTION” tags or similar identification to avoid accidental operation during filling or testing.

5.1.9 Primary shut-off valves in Instrument lead lines from the main lines and equipment shall be closed. Piping or tubing down steam of the valves shall be disconnected in order to prevent any pressure build up or introduction of foreign matter into the instrument system.

5.1.10 Instrument air sub-headers shall be isolated from the main header system by closing the block valves adjacent to the main header and disconnecting the first union down streams of each valve. Instrument connections shall be closed with a properly gasket blind flange, if flange connections are used.

5.1.11 Temporary gasket shall be used to blank off lines for pressure test purpose, unless specified otherwise. These shall be removed and replaced with new permanent gaskets after tests have been satisfactorily completed. However, permanent gasket shall be used for flange joints, which do not required to open again after testing.

5.1.12 Bolt tightening shall be in accordance with DOOSAN Procedure. 5.1.13 All post weld heat treatment of the weld joints shall be completed prior to testing.5.1.14 All NDE requirements shall be fulfilled & confirmed prior to testing.5.1.15 The pipe work system shall be flushed with water or blown with air in order to remove all

debris prior to testing.

5.2 Condition for pneumatic static test

5.2.1 Pneumatic test pressure

SYSTEM Design pressure Test pressure Remark

Instrument air line for Stack 10 bar 12.0 bar Design pr x 1.2

N2 filling line for Drum 11 bar 13.2 bar Design pr x 1.2

5.2.2 Measuring Tool and Installation (1) The pressure gauge install at temporary pipe.

(2) The pressure gauge for pressure test need to be calibrated and the certificate available at site prior to using in the pressure test. Locations of test gauges will be shown in the individual test-packs.

5.2.3 Communication(1) Radio: more than 2 walkie-talkies(2) Location: Control center (filling air valve and pressurization equipment area)

Top (pressure gauge and vent area) Inspector(3) Inspector and recorder must place in a convenient area to communicate for the pressure gauge Inspection of control center.

5.3 Pressure test equipments and instrumentsThe equipment and instruments to be used for testing will be checked, maintained, tested and serviced for continuing process capability.

(1) N2 Bottle unit for pressing pressure(2) Air Compressor.(3) The pressure gauges used in pressure testing shall have dials graduated over ranges of

about double the intended maximum test pressure, but in no case shall the range be less than 1 1/2 nor more than 3 times that pressure. The pressure gauges shall be calibrated from authorized calibration agency before use and re-calibrated at any time that there is reason to believe that they are in error. Each gauge shall have an identification number, which shall appear on the calibration certification record.

5.4 Pre-test piping walk down(If requires).(1) Safe access and any required temporary scaffolding shall be provided for inspection of

all joints and appurtenances prior to walk-down and maintained until the satisfactory

completion of the test.(2) Isometric drawings pertaining to the test package shall be listed on the Index of

Isometric Drawings.(3) On completion of piping installation, the system will be walked down by the Piping

Engineer and outstanding items will be documented on the Pipe work Punch List.

5.5 Pneumatic test of piping.

5.5.1 Pressure test shall be normally performed by hydrostatic method unless otherwise stated. Pressure testing of piping shall in accordance with the requirement of ASME B 31.1. For details, refer Para 5.7 of this procedure.

5.5.2 Pressure test should be carried out on complete system whenever practicable.5.5.3 Unless otherwise stated on the drawing, all pressure piping shall be tested in accordance

with the test pressure with test medium as per Line List of each system.5.5.4 All piping shall be pneumatic pressure tested when:

(1) Water is harmful to the service and cannot be dried completely.(2) Instrument air, utility air, nitrogen system and service air.(3) In case of piping connected to an equipment or vessel nozzle by welding and where the

Equipment is not included in testing, the piping shall be pressure tested before installation. After welding of the piping to equipment nozzle, the final joints shall be subjected to NDE (RT, UT, MT, PT as applicable) instead of pressure test.

(4) Lines which are open to atmosphere, such as vents, drains and open safety valve discharges. These lines shall be visually examined to verify that all joints are properly made up.

(5) Safety valves, flame arrestors, rupture discs and filter elements shall not be subjected to pressure test.

(6) Pressure gauges, thermometers, flow meters and other instruments shall not be subjected to pressure test.

(7) Rubber Expansion joints and steam traps shall not be subjected to pressure test.(8) Any other equipment designated by Siemens.

5.5.5 Where an item of equipment has been blanked off at a flanged joint during pressure test of piping, it shall not be necessary to pressure test the joint after the blank is removed. Such joints shall be visually examined to ensure that gaskets are properly installed, bolts tightened etc. and inspected for leaks during commissioning and service test. Flanged joints that are broken for pressure test purposes shall have a new permanent gasket installed after pressure test is completed prior to commissioning.

5.5.6 Piping that is repaired or modified after a pressure test shall be re-tested, except in cases

and agreement with Siemens, 100% NDE (RT, UT, MT, PT as applicable) may be substituted in lieu of retest.

5.5.7 100% NDE (RT, UT, MT, PT as applicable) may be substituted after agreement with Siemens instead of hydrostatic test for welded tie in portion with existing plant facility.

5.5.8 All joints including welds shall be left uninsulated and exposed for examination during testing except those joints previously tested in accordance with this procedure.

5.6 Preparation of piping systems for pressure test.

5.6.1 Piping shall be thoroughly vented of air before introduction of the test water. High point vents to be provided as required. Adequate measures shall be taken not to allow any air to remain in the high points of the tested system.

5.6.2 Temporary blind flanges and test blinds shall be installed at location shown on the marked up P&ID included in the Pressure Test Pack. Test blinds shall be of an adequate thickness to withstand the test pressure.

5.6.3 All internal parts and in-line items removed for the duration of pressure testing shall be labeled and the component to which they belong or the position in the line from which they were removed shall also be labeled to ensure correct replacement of components following the testing.

5.6.4 All valves, except as excluded specifically herein, shall be included in the pressure tests, ball valves shall be in the half open position and all other valves fully open.

However, where the test pressure to be applied to line is greater than the maximum allowable test pressures specified for the valves, the valve shall be blinded on the test side or replaced with a temporary spool.

5.6.5 Expansion joints shall be protected from excessive pressure of the hydrostatic tests generally by removing them. Metallic bellows expansion joints shall not be subjected to any pressure in excess of its shop test pressure.

5.6.6 All lines in vapor service shall have sufficient temporary supports to withstand weight of the test medium.

5.6.7 All temporary supports, spring support restraints, temporary spools, blinds and plugs etc. shall be prominently flagged or painted, to ensure their removal following testing.

5.6.8 The test pressure gauge shall be located at the high point of the system, a “Check” gauge shall, in additional, be located at the low point of the system if significant vertical legs could cause the static head pressure to over-pressure parts of the system.

5.6.9 All test manifolds shall be hydraulically tested and clearly marked for the maximum pressure rating.

5.7 Pneumatic Pressure test.

5.7.1 Pneumatic tests(1) Pneumatic test shall only be performed under the direct supervision of an experienced

engineer, who must ensure that test procedures and criteria are followed. All personnel involved with testing must be made aware of, and trained in, the procedures to be implemented, and be familiar with the hazards associated with this type of test. A pressure relieve valve shall be made available (for piping system of test pressure above 15 bar), having a set pressure no higher than the test pressure plus the lesser of 10% of the test pressure.

The relief valve shall be located at the first connection on the temporary line nearest the pressure sources. A bleed valve to facilitate de-pressurization shall be located at the test manifold readily accessible by the operator in case de-pressurization is required. An isolation valve rated for the test pressure shall be provided between the manifold and the system being tested.

(2) During the test, the area, which may be affected by blast, shall be cordoned off using colored tape. Signs shall be placed to indicate the danger. Flashing lights shall be used to designate areas under test during non-daylight hours.Entry to the cordoned area shall be restricted to the authorized personnel who are performing and witnessing the test.

(3) The system under test shall have warning notice tags affixed to all valves during the time that the system is pressurized.

(4) Welds and flanged joints shall be swabbed with soap solution to facilitate detection of leaks.

(5) The system under test shall be gradually pressurized to the lesser 50% of the test pressure and held for a sufficient length of time to allow piping to equalize strains. All joints (threaded, socket welded, butt-welded and flanged) shall be inspected for leaks with soapsuds.

(6) Pressure shall be increased in steps (each step to be not more than 10% of the specified test pressure) until the specified test pressure has been reached, held for a sufficient length of time at each step to allow piping to equalize strains. When the test pressure has stabilized the test pump shall be disconnected. The test pressure shall be maintained for 10 minutes. Visual inspection of all joints and components for leaks with soapsuds shall be performed at the lesser of design pressure or 7bar(G)

(7) The pneumatic test pressure shall be either from 120% up to maximum 150% of the design pressure, or as mutually agreed pressure between Doosan and Siemens

Representatives.(8) Throughout the testing period, the pressure is to be closely monitored to ensure that

over-pressuring due to thermal expansion does not occur.(9) The pressure test of the piping system shall be recorded on the Pressure Test

Certificate.(10) After completion of a pneumatic test the system shall be de-pressurized in a

safe manner under the direction of a supervising Engineer.

5.8 Venting / flushing.

5.8.1 All lines shall be thoroughly vented immediately after testing. Care shall be taken to ensure against damage by vacuum to any apparatus or piping by first opening all vent valves and removing high point vent plugs.

5.8.2 Special precautions should be taken to ensure the drainage of all pockets where the testing fluid may be trapped.

5.9 Post test reinstatement.

5.9.1 Following acceptance of a successful test, the system shall be immediately depressurized and vented in a gradual and safe manner, thoroughly drained allowing no pockets of fluid to remain. Prior to draining out test medium, all valves in partially open position shall be fully opened after dropping pressure to system pressure. For pneumatic tests, warn people in the vicinity prior to release of pressure open vent valve slowly keeping clear of discharge and ensure vented air or nitrogen cannot cause danger.

5.9.2 All item removed for the test shall be replaced and all test blinds, temporary supports, etc. shall be removed. The replacement of piping component internals shall be carefully controlled to ensure that they are reinstalled in the correct place. Flanged joints opened for these purposes shall be re-made with new gaskets.

6.0 DOCUMENTATION.The test pack shall be prepared and submitted to Siemens for review/approval prior to testing. The test pack shall include following:

(1) P & I Diagram (Marked up to show test limit)(2) Isometric Drawings (Marked up to show test limit)(3) Index of Isometric Drawings(4) Weld Inspection Summary Sheet(5) Pipe work Punch List(6) Pressure Test Certificate(7) Pipe work Re-instatement Checklist(8) Mechanical Completion Checklist

7.0 ATTACHMENTS.

Annexure -Ⅰ: Flow Chart for Pneumatic Testing

Annexure -Ⅱ: Organization Chart for Pneumatic Testing

Annexure -Ⅲ: Pipe Work Punch List

Annexure -Ⅳ: Weld Inspection Summary Sheet

Annexure -Ⅴ: Index of Isometric Drawings

Annexure -Ⅵ: Pressure Test Certificate

Annexure -Ⅶ: Pipe Work Re-Instatement Check List

Annexure -Ⅷ: Mechanical Completion Check List