METHOD STATEMENT FOR UNDERGROUND PLUMBING WORK

METHOD STATEMENT FOR UNDERGROUND PLUMBING WORK_Method Statements for Method Statements For General Concrete Work Works and to details out the steps to be taken in meeting the technical requirements of Van Phong 1 thermal power plant project

PLUMBING WORK

Document Type For Approval

No Section/

Page

Date

Status O/C * Remarks

Please clearly state the extent this system includes - potable water supply, sanitary drainage, waste drainage, chemical drainage, etc

drainage as applicable.

[Rev.B]

This method statement includes - potable water supply, sanitary drainage, waste drainage, chemical drainage, etc

Provide reference documents of piping material specification.

[Rev.B]

This MS is related with procedure of underground plumbing work, and approval for plumbing material is being submitted separately

- uPVC: VP1-0-L4-Q-GEN-10040

- cPVC: VP1-0-L4-Q-GEN-10049

- Carbon steel: VP1-0-L4-Q-GEN-10061

- Stainless steel: To be submitted

C

Complete reference drawing number to close out this com-ment

Page 2 of 4

Lists all drawing number under reference drawing list for clarity of applicability of this document

[Rev.B]

Since plumbing drawings are submitted for each building, it is difficult to indicate the drawing numbers of all buildings Hence, turbine building and CCB drawing for underground plumbing work were issued as mentioned below;

- VP1-C-L4-C-UMA-29601, D (Turbine)

- VP1-0-L4-A-UCB-02401~4, B (CCB)

Only plastics pipes? No SS, etc underground pipes for plumbing system? Please clarify

[Rev.B]

The table has been updated

Typical drawings, P&ID, isometric drawings, and/

or schematic drawings should be given as reference

[Rev.B]

Please refer to the submitted plumbing drawings

- VP1-C-L4-C-UMA-29601, D (Turbine)

- VP1-0-L4-A-UCB-02401~4, B (CCB)

Relevant project specification to be list as reference

[Rev.B]

- Part III-2 Exhibit B1 Appendix G - Civil Structural Technical

- Part III-2 Exhibit B1 Tech Spec Section 8

Who? CTCI or Doosan or VPCL? Please review and clarify

[Rev.B]

All materials required should be approved by the VPCL (and Poyry) who is Owner of Van phong-1 project

Noted Closed

C

C C

C

Consider material is PVC pipe, recommend to apply sand bedding and backfill around the pipe to avoid pipe damage.

[Rev.B]

Sand bedding and manual backfill around the pipe to be applied

Provide typical of trench section, that shown typical dimension, and depth of trench, bedding, embedment, and cover according to designed compressed load on top of pipe.

[Rev.B]

Typical section to be updated as per comment

But It will be changed depending on pipe size or site condition

Why raw water is allow to used? It is possible to contaminate in potable water?

[Rev.B]

Test medium shall be used by potable water only

ITP specify 2 hrs Which is correct?

[Rev.B]

It is revised to 02 hrs

Is this leak test done before or after back-fill?

Describe more to repair method in this document.

[Rev.B]

After the leak test done shall be backfill

Indicate test pressure

[Rev.B]

Design requirement for test pressure of Portable water supply line in building is 4bar.

Provide with project document numbering This document should be conformed to design standards/ local regulation

[Rev.B]

This pressure test is to check whether the pipe is leaked, and is conducted according to the design required pressure and code.

C

Closed

C

C C

Clarify test pressure according to design pressure

Hydrostatic test pressure shall be complied to ASME B31.1 Please recheck and confirm

Page 4 of 4

Calibration certificated should be attached with the test record

[Rev.B]

Calibration certificated will be attached with the test record

Describe more about method to remove foreign matter inside of piping

[Rev.B]

Revised as per comment

Gravity-slope line shall be lay on sleeper and fixed

to ground at design level

[Rev.B]

Revised as per comment

Test pressure shall be 1.5 design pressure according to 137.4.5 ASME B31.1

[Rev.B]

Revised as per comment

ITP document L4-A-UYX-20024 Rev A doesn't match with this document Please review and correct these documents/ any orher EPC document (if applicable) to avoid any possible mismatch.

[Rev.B]

MS and ITP have revised and submitted

Additional Notes (if any)

* O - Open, C – Closed

C

Closed Closed

C

C

OWNER

VAN PHONG POWER COMPANY LIMITED

PROJECT

Van Phong 1 BOT Thermal Power Plant Project

Pöyry Switzerland Ltd

Status

□Approved

□Approved with Comment

□Not Approved

□Reviewed

EPC CONTRACTORS

IHI –TESSC–CTCI–DHI CONSORTIUM

PROJECT DOCUMENT No

VP1-0-L4-A-UYX-20023

REV

B DOCUMENT TITLE

METHOD STATEMENT FOR UNDERGROUND PLUMBING WORK

EPC

Doosan Heavy Industries and Construction

EPC DOCUMENT No

VP1-0-L4-A-UYX-20023

REV

B

For Approval

Approved

Contractor to revise the correction and resubmit

Revise the correction and resubmit before proceeding

Information acknowledged with no comment

Information acknowledged with comments Note: Approval or comment does not relieve the Contractor of

Discipline:

all obligations covered under contract

Date:

Mechanical / Architectural

14 Jul 20

TABLE OF CONTENTS

1 PURPOSE 3

2 MACHINERY & EQUIPMENT 3

3 RESPONSIBILITIES 4

4 MATERIALS 4

5 PROCEDURE & SEQUENCE 4

6 WORK METHOD/PROCEDURE 7

7 QUALITY CONTROL 11

8 ENVIRONMENT, HEALTH AND SAFETY (EHS) 11

METHOD STATEMENT FOR UNDERGROUND PLUMBING WORK

1.0 PURPOSE

The purpose of this Method Statement is to describe the methodology involved on the installation of underground plumbing work such as potable water supply, sanitary drainage, waste drainage, chemical drainage, oily drainage as per plumbing drawing limited in building the steps to be taken in meeting the technical standards and EHS requirements of Van Phong 1 BOT Thermal Power Plant

Plant Project/Project: Van Phong 1 BOT Thermal Power Plant Project

Company/Owner: Van Phong Power Company Limited (VPCL)

Reference document:

- TCVN 4519:1988 Indoor water supply and drainage systems - Codes for construction, check and acceptance

- Project technical requirement

- Approval civil construction drawing

Reference drawing list for clarity of applicability of this document:

+ VP1-C-L4-C-UMA-29601, D (Turbine)

+ VP1-0-L4-A-UCB-02401~4, B (CCB)

2.0 MACHINERY & EQUIPMENT

1

Clamping tool & hand tools : measuring and leveling tools, glue roller, knives, scissors, screw driver, plumbs

2 Required machine for joint: Cutting machine, welding machine, Sander, (if required as per manufacture recommend)

3 Consumables : Pipes and fittings, duct tape

B

B

B

3.0 RESPONSIBILITIES

It is overall responsibility of Project Manager to organize resources prior to perform construction activities as per project specification in compliance with the quality, schedule & safety requirements EHS Manager will ensure in coordination with Site Engineer that all measure/construction taken shall

be maintained till completion of job

It is the responsibility of Construction Manager/Site Engineer that construction activities are executed according to the relevant project specification in compliance with the quality, schedule & safety requirements

EPC will ensure that all works are performed safely

The relevant EPC Supervisor will ensure that the work is carried out in accordance with this method statement and project specification

The QC Inspector will ensure that the work is executed according to the requirements of quality dossier are fulfilled

4.0 MATERIAL

All materials required shall be approved by the VPCL (and Poyry) who is Owner of Van Phong 1 project

All materials required shall be true to size, without cracks, chips, splits, or other defects which may impair their strength or durability

Material should be taken receiving inspection with all their certificate from factory approved

5.0 PROCEDURE AND SEQUENCE

5.1 The Contractor shall furnish all labor, tools and materials necessary for the complete installation of the plumbing system which includes pipe lines inside(including under) Buildings

5.2 Underground Soil, Waste, Drain and Vent Pipe and Fittings - Underground soil, waste, drain and vent pipe and fittings shall be uPVC; CPVC pipe

5.3 Under slab sanitary sewer pipes from fixtures to the building main shall be uPVC pipe Fittings shall

be uPVC and solvent weld shall comply ASTM D2564 solvent cement (or product of manufacture) 5.4 Potable water pipe and fittings shall be stainless steel complied with ASTM A312-TP304

5.5 All excavation shall be restored to its required level The bottom of trench shall be dry prior to installation After installation, all pipe ends shall be capped to prevent egress of unsuitable materials Sand bedding and manual backfill around the pipe to be applied to avoid pipe damage

B

B

Please change to "or VPCL's representative"

METHOD STATEMENT FOR UNDERGROUND PLUMBING WORK

5.6 The trench bottom shall be continuous, smooth, free of rocks and in accordance to the line and grade shown in the drawing

Typical section of trench shall be changed depending on pipe size or site condition as below:

Typical section of installation pipe 5.7 Testing:

Service Test for Gravity-Slope line

• Gravity (Sanitary drain, Sewage drain, and chemical drain, Oily drain) drainage system shall be subjected to service test

• Service Test Inspection shall be conducted after complete backfilling has been done for installed gravity-slope drainage line

• Service test shall be done prior to concrete works to ensure no leakage on installed gravity-slope underground piping cause by excavation damage or by any other causes

• Water level in pipe shall be checked for confirmation of water leakage during test 2hr

• After the leak test done shall be backfilled

• Test medium shall be used by potable water or raw water

Hydrostatic test for Portable water line

• Pressure (Portable water line, Water supply, Hot water line) system shall be subjected to hydrostatic test in accordance with Doosan Quality and Safety Management Plan

• Test medium shall be used by potable water only

B

B

B

• Lines whose joints have not been backfilled for underground piping or are above ground piping shall

be tested to a period of 1 hours while 2 hours shall be maintained for lines whose joints have been backfilled or concealed

• Test Limits, pressure, test medium and safety requirements shall be identified Design requirement for test pressure of Portable water supply line in building is 4bar

• Temporary supports shall be installed wherever required

• All joints shall be left exposed for visual inspection during test

• Underground piping shall be partially backfilled with all joints exposed to serve as a pipe support and prevent floatation

• Work Permit is obtained for all pressure testing and associated work within restricted areas, Work Permit System

• The test areas shall be marked and warning signs shall be posted to alert approaching personnel

• A blow down valve of adequate pressure rating is installed to depressurize the system

• The relief valve shall be located in the test manifold near the test pump

• A pressure gauge shall be located at the test manifold and one pressure gauge on the furthest route of the piping network being tested Calibration certificated will be attached with the test record

• Vents shall be provided at all high points in the system being tested

• A blow down valve or bleed valve shall be readily accessible in case immediate depressurization is required

Hydro test Crew

• Hydrostatic Testing shall be done by trained personnel in the proper handling and usage of applicable tools and equipment prior to start of hydrostatic Testing

• Personnel conducting the hydrostatic testing shall be fully aware of the general requirements of safe pressure testing of pipelines

Pressurization

• No Thermoplastic Piping shall be pressurized until it has cured for 24 hours at a surface temperature

of 10°C or higher

• The test pump & test manifold shall be placed on a firm ground away from the piping being tested

• The test manifold shall be supported firmly to avoid vibration during pressurization

• All in line valves are in open position

B

B

Is it potable water?

Regarding VP1-0-L3-R-GKB-22001 rev D, potable water pumps head is 55.97 m Please ensure that test pressure is sufficient and com-plied to ASME B31.1

METHOD STATEMENT FOR UNDERGROUND PLUMBING WORK

• Filling and pressurization is injected at the test manifold upstream of check valves and at the lowest point of the system being tested to minimize entrapped air

• Water filling into the system shall be direct from a water truck or form a ground level water tank with pump

• Remove air during filling of water by opening the vents installed at high points and shall be closed when air has been released from the system

• After venting, valves used for venting are placed at partial open position and plugged

• Vents and drains used only for the pressure test shall be plugged or seal welded

• To pressurize the system, motorized or manual test pumps shall be used depending on the size of the system being tested

• The system shall be pressurized slowly

• Preliminary check for leaks at 50% of the test pressure shall be done

• The pressure is increased in steps no greater than one-fifth of the test pressure after the preliminary check at 50% test pressure Each step in pressurization is held at minimum of 10 minutes

• After the test pressure is reached (before inspection), the isolation valve between the test manifold & the piping system under pressure test is closed and the test pump disconnected

• No repair of leaking joints until the system has been de-pressurized

Depressurization and Draining of Test Medium

• After pressure testing has been successfully completed and approved, the piping system being tested shall be depressurized and drained

• Release of pressure and draining shall be done on the downstream side of check valves

• All vents shall be opened before draining to facilitate drainage and to prevent formation of a vacuum

• Water used for hydrostatic testing can be used for another test, to be used for water spray of trenches,

to be used for water flooding of pipe sand covering or to a safe and approved discharge area

• All temporary items installed for testing purposes shall be removed

• All pipe ends shall be covered after draining the system to prevent entry of foreign materials into the system

6.0 WORKING METHOD/PROCEDURES

6.1 Check the protection cover of both ends of the pipe and remove any dust that may remain in the piping with water and brush before installation

B

6.2 Adequately support vertical lines at their bases or by a suitable hanger place in horizontal line near riser or by a base fitting set on pedestal

6.3 Run piping in straight lines and square with the building Gravity-slope line shall be lay on the sand bedding as shown clause 5.6 above and fixed to ground at design level Riser lines to be plumb Provide dielectric fittings for connecting dissimilar metals

6.4 Do not route piping over any electrical equipment where the possibility of damage exists Provide flanges and unions throughout piping system to facilitate the installation and removal of piping and equipment

6.5 Sewer lines shall not cross over water line In case inevitable, suitable measures at the crossing shall

be taken

6.6 Valves shall be installed in horizontal lines with stems either horizontal or vertical Isolation valves shall be installed at any other points indicated or required for draining, isolation, or sectionalizing purposes as per Drawings Valves shall be installed such that maintenance access is maintained for all parts requiring service Control valves shall be provided in water pipes to provide complete regulation

of plumbing fixtures and equipment

6.7 Provisions must be included for servicing and removal of equipment without dismantling piping works Place sanitary sewer pipe, drain pipe and chemical pipe, oily pipe at elevation and slopes as per drawing

6.8 Preparation for the first fix shall commenced immediately upon completion of civil works

6.9 Marking for the pipe route considering the other agencies shall be done with due consideration for slopes and tapping points as per the drawings

6.10 After the chasing works, the pipes shall be concealed

6.11 The process of installing pipelines shall be inspected by the stakeholders and ensured to follow the required procedures (There will be no leak if the installation process follows the right procedures) Visual leak check shall be carried-out after the installation The visual leak test result shall be provided

in the ITP during inspection process

The leak test shall be applied with drainage pipe line With pressure pipe line such as portable water line and hot water line will be applied to hydrostatic test

B