16-Piping Flushing Procedure (Kqc 16)

PIPING FLUSHING PROCEDURE (KQC 15)

PIPING FLUSHING PROCEDURE FOR Cairo West Thermal Power Plant2*350MW Unit (7&8) Project CONTRACT No. 10051-CP-106

MECHANICAL EQUIPMENT &PIPE INSTALLATION Document No. : KQC 15 /Cairo West /01 Rev # 0

Rev. Date

Prepared by

Reviewed by

.MAR QA/QC Engineer

0

2009

Eng. / SHERIF ESSAM

QA/QC Manager Eng. /saadawy allatif

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Approved by

PIPING FLUSHING PROCEDURE (KQC 15)

TABLE OF CONTENTS TITLE 1.0 Purpose 2.0 Scope 3.0 Precautions 4.0 Responsibilities 5.0 Requirements 6.0 Flushing Operation Preparation 7.0 Flushing operation activities 8.0 Post flushing activities 9.0 Drying (when required) 10.0 Flushing Operation Duration

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PIPING FLUSHING PROCEDURE (KQC 15) 1.0 Purpose: To provide guidelines for the inspection of cleaning of piping system and to provide the startup engineer with a general sequence of events to be followed to ascertain system cleanliness in a safe and consistent manner.

2.0 Scope: This procedure covers inspection activities for cleaning of piping system after assembly and completion of testing.

3.0 Precautions: 3.1 If at any time during the implementation of this procedure, any parameter or condition is out of acceptable limits and can not be readily corrected, the operation will be terminated and the system left in a safe condition. 3.2 Any unusual and partial test completion or other information pertinent to the operation should be documented. 3.3 The test engineer will limit personal in the area to those performing test or authorized witness .All other will remain out side the test area as defined by the test engineer.

4.0 Responsibilities: CP-106 Field Engineer / QC Engineer is responsible for implementing the requirements of this procedure

5.0 Requirements: Each system should be flushed immediately after testing while inline instruments control valves, etc… are out of the line or isolated.

6.0 Flushing Operation Preparation: 6.1 CP106 will manage piping flushing system to ensure that the flushing will remove any debris and other foreign materials, flushing procedure shall include the flush inlet and outlet points, each flush shall meet the following criteria :a)Flushing velocities shall be minimum of 2.5 F/S in all parts of the system. b)Cone strainer shall be installed in the connection to attached equipment and left there until cleaning has been accomplished. 6.2 CP-118 Ensure that each system flush is set up in such away that the flow of debris and foreign material is downhill to the exit point to avoid settling out at highpoints. 6.3 CP-118 will manage the flush inlet(s) which shall be at or near the high point (s) and the outlet(s) at or near the low points of the system.

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PIPING FLUSHING PROCEDURE (KQC 15) 6.3 CP-106 Ensure that the correct type of water is used for each flush, clean fresh water for all lines except austenitic stainless steel where low chloride water shall be used (except for oil system, in which case oil should be used). 6.5 Review system flushing /drying report

7.0 Flushing operation activities : 7.1 Ensure all system valves are closed. 7.2 Ensure the flushing source supplying the head is available. 7.3 Isolated flushing supply and make the system safe. 7.4 Ensure that flushing fluid is circulated through all portions of the system. 7.5 Witness measurements by the contractor to ensure that the minimum flushing velocity is being maintained. 7.6 Re-instate system integrity. 7.6 Witness the cleanliness of flush water to determine when the system is clean. Sign the system flushing / drying report and the relevant P&ID.

8.0 Post flushing activities 8.1 8.2

Ensure that lines designated as requiring drying are dried immediately after the completion of flushing. Ensure that lines not required drying are restored.

9.0 Drying ( when required ) 9.1 Before the system is dried, check the following: a) Control valves and in-line instruments which may be damaged are removed and replaced as necessary with pipe spools or isolated. b) Blow point drains & branch lines are open as needed & the areas around them are clear of material & personal. Add barricades and noise control and protection if it is the case. 9.2 Ensure that oil - free dry air (- 40 oF dew point) or nitrogen is available to be used to purge the piping until -29 oC (-20 oF) dew point is reached. Each low point drain and the end of each branch line are to be blown until the - 29 oC (- 20 oF) dew point is reached. 9.3 Witness (MHI /PGESCO) the dew point readings of each system. Sign the system flushing /drying report. 9.4 After approval is received, ensure that the control valves and in – line instruments removed during the drying are reinstalled. 10.0 Flushing Operation Duration: Period of flushing : minimum 2 hours.

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