IS 15663-3 (2006): Design and installation of natural gas ......OISD-STD-118 Layout of oil and gas installations OISD-STD-117 Fire protection facilities for petroleum depots, terminal

Disclosure to Promote the Right To Information

Whereas the Parliament of India has set out to provide a practical regime of right to information for citizens to secure access to information under the control of public authorities, in order to promote transparency and accountability in the working of every public authority, and whereas the attached publication of the Bureau of Indian Standards is of particular interest to the public, particularly disadvantaged communities and those engaged in the pursuit of education and knowledge, the attached public safety standard is made available to promote the timely dissemination of this information in an accurate manner to the public.

इंटरनेट मानक

“!ान $ एक न' भारत का +नम-ण”Satyanarayan Gangaram Pitroda

“Invent a New India Using Knowledge”

“प0रा1 को छोड न' 5 तरफ”Jawaharlal Nehru

“Step Out From the Old to the New”

“जान1 का अ+धकार, जी1 का अ+धकार”Mazdoor Kisan Shakti Sangathan

“The Right to Information, The Right to Live”

“!ान एक ऐसा खजाना > जो कभी च0राया नहB जा सकता है”Bhartṛhari—Nītiśatakam

“Knowledge is such a treasure which cannot be stolen”

“Invent a New India Using Knowledge”

है”ह”ह

IS 15663-3 (2006): Design and installation of natural gaspipelines - Code of Practice : Part 3 Pre-commissioningand commissioning of pipelines [CED 7: StructuralEngineering and structural sections]

IS 15663 (Part 3) :2006

R-qTq-=fi *

Indian Standard

DESIGN AND INSTALLATION OF NATURAL GASPIPELINES — CODE OF PRACTICE

PART 3 PRE-COMMISSIONING AND COMMISSIONING OF PIPELINES

KS 75.200

,,,

(3 BIS 2006

BUREAU OF INDIAN STANDARDSMANAK BHAVAN, 9 BAHADUR SHAH ZAFAR MARG

NEW DELHI 110002

April 2006 Price Group 3

Structural Engineering and Structural Sections Sectional Committee, CED 7

FORE WORD

This Indian Standard (Part 3) was adopted by the Bureau of Indian Standards, after the draft finalized by theStructural Engineering and Structural Sections Sectional Committee had been approved by the Civil EngineeringDivision Council.

NaturaI gas has been utilized in the country for many years. With increased exploration efforts and enhancedproduction, utilization of natural gas has also increased. Natural gas is considered to be much more environmentfriendly and is therefore being preferred as an ahemate fuel. Natural gas is envisaged to be an emerging fhel inthe country and is slated to cater to a major portion of the country’s energy requirement. The utilization of naturalgas is, however, largely dependent on an efficient transmission and distribution network through pipeline systems;connecting gas sources, gas production plants, process plants, storage facilities, to the users/consumers spreadacross long distances. Towards this objective of its efficient usage, there is a focus on development of pipelineinfrastructure through extensive pipeline networks for transmission and distribution of natural gas in the country.

Considering the above, a need was felt to develop a standard that prescribes the requirements necessary for thesafe design and installation of such pipelines and its testing and commissioning. The recommended actions setout in the standard are intended to protect the public life as well as the environment from possible hazards intransportation of the gas. The recommendations are applicable to conditions that are normally encountered andadditional design considerations may be necessary where unusual conditions are encountered. The standard ispublished in three parts. The other parts in this series are:

Part 1 Laying of pipelines

Part 2 Laying of pipelines in crossings

The standard keeps in view the practices in the country in the field and the safety considerations in followingguidelines of the Oil Industry Safety Directorate: .,, ,

OISD-STD- 141 Design and construction requirement of cross country hydrocarbon pipelines “

OISD-STD-118 Layout of oil and gas installations

OISD-STD-117 Fire protection facilities for petroleum depots, terminal and pipeline installations

Assistance have also been derived from the following international standards:

1S0 13623 Petroleum and natural gas industries — Pipeline transportation systems

ASMEB31.8 Gas transmission and distribution systems

APIRP 1102 Steel pipelines crossings railroads and highways

API RP 1104 Welding of pipelines and related facilities

IS 15663 (Part 3) :2006

Indian Standard

DESIGN AND INSTALLATION OF NATURAL GASPIPELINES — CODE OF PRACTICE

PART 3 PRE-COMMISSIONING AND COMMISSIONING OF PIPELINES

1 SCOPE

This standard (Part 3) covers the minimum requirementsfor pre-commissioning and commissioning of naturalgas pipeline, including pre-commissioning activitiessuch as pre-commissioning checks, flushing, dewatering,swabbing, magnetic cleaninglelectronic geometrypigging (EGP), drying, iner.tisation, gas-in andcommissioning, stabilization and 72 h run.

2 REFERENCE

The standard given below contains provision whichthrough reference in this text, constitutes provision ofthis standard, At the time of publication, the editionindicated was valid. All standards are subject torevision and parties to agreements based on thisstandard are encouraged to investigate the possibilityof applying the most recent edition of the standardindicated below:

IS No. Title

15663 (Part 1) : Design and installation of natural2006 gas pipelines — Code of practice :

Part 1 Laying of pipelines

3 TERMINOLOGY

For the purpose of this standard the definitions givenin IS 15663 (Part 1) shall apply.

4 GENERAL

Procedures shall be established for pre-commissioningand commissioning activities. These shall consider thecharacteristics of the gas being conveyed, the need toisolate the pipeline from other facilities and the transferof the pipeline for operation. The procedures anddevices shall be such that nothing, that is, incompatiblewith the gas being conveyed or with the materials inthe pipeline components is introduced into thepipeline system. Pre-commissioning shall becommenced only on completion of all activitiesrelated to the pipeline construction which includeshydrostatic testing, complete backfilling, installationof field instruments/equipments and suitable cathodicprotection system.

The commissioning of the pipelines shall essentiallyconsist of the following operations:

a)

b)

c)

d)

pre-commissioning checks;

swabbing;

inertisation; and

commissioning.

5 PRE-COMMISSIONING

5.1 Pre-commissioning shall include the following:

a)

b)

c)

d)

e)

De-watering of residual water of the pipeline;

Flushing and dry air blowing of above groundpiping at dispatch and receiving stations,sectionalizing valve stations, intermediatepigging stations and hook-up point;

Swabbing of pipeline;

Low pressure leak check (with air) for theabove ground section of the pipelines; and

Preparation of pre-commissioningprocedures for all activities related to pre-commissioning. ,.. .

5.2 -Pre-commissioning Procedure

5.2.1 Pre-commissioning Checks

Pre-commissioning checks shall be carried out for thepipeline system up to first isolation valve to ascertainthat the pipeline system has been mechanicallycompleted in all respects. These checks-shall cover themain pipeline including distribution network system,dispatch and receipt stations, intermediate piggingstations, sectionalizing valve stations and the hook uppoints. The pre-commissioning checks shall includethe following

a)

b)

c)

Checking of pipe cover — Cover-check overpipeline for every 500 m with suitableinstruments (like pipe current measurement,PCM; etc) shall be carried out.

System checks — The entire facilities shallbe checked against drawings fdocuments andother design specifications. Any observationrequiring correction/corrective action shall berecorded and complied with.

Checking offield instrumetits/equipments —

A1lthe field instruments like actuated valves,control valves, shut down valves, transmitters,solenoid valves, shut down switches, alarms,

1

IS 15663 (Part 3) :2006

d)

e)

f)

~)

h)

j)

k)

etc, shall be checked physically and also fortheir intended application. It will also includechecking of different meters, gauges,actuated valves, control valves, shut downvalves, etc.

Pipeline survey — This shall be performedto confirm that proper fittings/supports,cathodic protection system, route markers,warning signs, fencing around sectionalizingvalve stations, crash barriers, etc, have beeninstalled along the pipeline and crossings.

Communication system — Communicationsystems shall be checked for adequacy toensure uninterrupted communication.

Electrical distribution system — Electricalinstrumentation system shall be checked toensure an uninterrupted power supply duringstartup and normal pipeline operation. Earthresistance of all earth pits and equipments,towers, lightning arresters, etc, shall also becarried out. Electrical fixtures shall bechecked for their compliance to the areaclassification requirements for such purpose.

Checking -of instruments control andinterlocks — This check shall be carried outto ensure that instrument controls andinterlocks are functional as per the normaloperating conditions.

Utilities — Utilities like power, UPS, water,air, instrument air conditioning, etc, shall bechecked.

Alarm systems — Setting off alarms and itsfunctioning shall be ensured.

Safety— Identification of possible emergenciesand preparedness for its mitigation shall bechecked.

Any other checks as considered necessary shall alsobe carried out.

5.2.2 Swabbing

5.2.2.1 Swabbing operation

The swabbing operation shall be done subsequent todewatering operation for removal of residual water inthe pipeline prior to final dryin-g, inertisation andcommissioning of the pipeline system. This is done bydriving number of suitably designed absorbantpigs propelled by oil free compressed dry air. Forthe purpose of swabbing, air compressors ofrequired capacity, after-coolers and driers should bedeployed.

5.2.2.2 Acceptance criteria

-Swabbing operation shall be considered to be completewhen there is no free water left in the pipeline as

indicated by increase in weight of less than 10 percentof the original weight (prior to launching) of the lastretrieved pig or when pigs are received in touch drycondition.

5.2.3 Low Pressure Leak Check for Above GroundPiping

5.2.3.1 The above the ground piping sections of thepipeline system shall be checked for leaks at flangepoints of piping and equipment, instrument impulsetubing points, etc. This shall be done by pressurizingthe.piping system/equipment with dry compressed air(for this purpose, oil free air compressors shall be used)and testing by means of soap solution/suitable digitalgauge for leaks.


The leak check operation shall be considered tohave been completed when the piping system/equipment is free of leaks when tested at a pressureof 6.0 kg/cm2.

6 COMM-ISSIONING

6,1 General

Commissioning of a pipeline shall be considered tobe complete when the line has been charged withproduct natural gas at-the operating pressure and theentire system has been operated at operatingparameters for a minimum period of 72 h with allinstruments, controls and interlocks working atnormal operating conditions.

Commissioning shall include magnetic cleaning,E(3P, drying, inertisation, gas-in, stabilization and72 h run.

6.2 Commissioning Procedure

6.2.1 Magnetic Cleaning

In order to ensure that the pipeline is free frommetallic debris, the magnetic cleaning shall becarried out using a train of hi-directional brushmagnetic pigs after the completion of swabbing andtie in. The operation shall be carried out using superdry air. A detailed procedure and the sequence ofthe operations shall be prepared before starting theoperation.


The magnetic cleaning of the section will be acceptableif the total ferrous debris collected is less than 5 kg/100 km in the last pig.

6.2.2 Electronic Geometty Pigging (EGP)

Calliper survey shall be carried out using super dry air

2

after the swabbing and magnetic cleaning operationsfrom the pig launcher to the pig receiver.

6.2.2.1 Pig tracking

The movement of any type of pig put into the pipelineduring magnetic cleaning and electronic geometrypigging shall be monitored along the pipeline lengthfrom launcher to receiver trap.

6.2.2.2 Electronic geomet~ pig runs

The electronic geometry pig should be capable ofrecording the entire length of each segment that is, fi-omthe launcher to receiver, in one single run and thereforeits electronic recorder system should have the requisitedata storage capacity. The measurement shall coverthe entire (360°) of internal pipe wall circumferenceusing properly oriented and sufficient quantity ofsensors. The tool shall be capable of identifying andlocating the following features:

a) individual girth weld;

b) dent, ovality, buckles or any other out ofroundness;

c) change in pipeline internal diameter anddifference of thickness; and

d) valves.

“Repair of defects shall be carried out in accordancewith that specified in IS 15663 (Part 1).

6.2.2.3 Sign@ance ofdefects

The following information/performance shallbe expected out of the electronic geometry piginspection:

a) Inspection of entire length of each segmentto be completed in one single run; and

b) Tools of a minimum detection level of2 percent of internal diameter shall beselected. The accuracy of measurement shallbe 1 percent of the internal diameter and2.5 percent of the measured value. Thelocational accuracy of the axial measurementshall be 0.1 percent from permanent features.The tool shall be capable of negotiating aminimum bend of 3 times the diameter and a15 percent reduction in internal diameter ofthe pipe.

6.2.2.4 Final work report

Any reporting system shalllimited to the following:

include but shall not be

a) A detailed report in respect of each pipesegment of running each of the pre-inspectiontools such as magnet cleaning pig;

3

b)

c)

d)

e)

f)

IS 15663 (Pm-t 3) :2006

Detailed report of the running of the electronicgeometry pig including but not limited to theoperational and functional details;

Detailed description of the type, size andlocation of individual mechanical defects. Thelocation and orientation of each defect shouldbe suitably listed with reference to permanentpipeline features, girth weld number, relativeand absolute distance;

A detailed report in respect of each defect forwhich sizing has to be done, indicating itslength, depth and axial location suitablyreferenced;

Preliminary site report for each pipe segmentfor each running of magnetic cleaning, andelectronic geometry pig runs, stating thecomments/observations of each run, pigcondition, operating parameters, and totaltime required; and

Velocity plot of the electronic geometry pigalong the length of the segment.

6.2.3 Drying

6.2.3.1 Requirements

The pipeline system including the under groundpipelines and the above ground piping at dispatch andreceipt stations, sectionalizing valve station,intermediate pigging stations and hook-up/tap-of pointsneed to be dried prior to charging natural gas. Dryingis required to prevent internal corrosion of the pipelineover a prolonged period of operation and to meet thesupply specification of the product natural gas and alsoas a means of preservation of the pipeline sectionssubsequent to the pre-commissioning activities.

The pipeline shall be dried by using super dry air orby any other suitable method (for example, vacuumdrying process). A detailed procedure and the durationof the operation shall be prepared and approved beforestart of drying operation.


The drying operation shall be complete beforeproceeding to the next step of inertisation. The dryingof the pipeline system shall be considered to have beencomplete on attaining a water dew point of (–) 10°C atatmospheric pressure. The pipeline system shall thenbe left at a pressure of 2.0 kg/cm2 with dry air at thisdew point after the drying operation and maintainedat this pressure and dew point till the commencementof the subsequent commissioning activities ofinertisation and gas-in. Alternatively, nitrogen can bepurged to break the vacuum for inertisation afterattainment of the desired dew point of (–) 10°C in thepipeline and a dew point profile test, provided that the

IS 15663 (Part 3) :2006

gas-in is carried out immediately after breaking of thevacuum by nitrogen.

6.2.4 Commissioning Checks

Commissioning checks -including pre-startup safetyreview prior to start of commissioning activities shallbe carried out to achieve a ready for commissioningstatus for underground pipeline and above groundpiping system at dispatch and receipt stations, aboveground pipingsystem at intermediate pigging stations,sectionalizing valve stations and hook-up/tap-off pointsand before pressurized entry of natural gas into thenew pipeline facility.

6.2.5 Inertisation

The inertisation of the entire pipeline system includingunder ground pipeline and the above ground piping atdispatch and receipt stations, intermediate piggingstations and hook-up/tap-off points shall be carried outusing nitrogen gas.

6.2.5.1 Operational requirements

During the inertisation operation, the dry air left in thepipeline shall be replaced by dry nitrogen beforeadmitting the natural gas into the pipeline for safecommissioning. Depending on the commissioningplan/strategy, seciions of the pipeline system shall betaken up for commissioning in steps. It is recommendedthat nitrogen slugs separated by pigs be used forinertisation of the under ground pipeline. The amountof nitrogen shall depend on the length of the pipelineportion to be taken up for commissioning. In general,the totalized length of the nitrogen slugs must be atleast 10 percent of the total length of the pipeline underconsideration. The nitrogen in the pig train shall bepropelled by natural gas (during commissioning. stageof the pipeline). For above ground piping at dispatchand receipt stations, sectionalizing valve stations,intermediate pigging stations and hook-up/tap-offpoints, the piping shall be purged with nitrogen till theresidual content in the pipline is below 1 percent(vol/vol).

Nitrogen used for inertisation purpose of the pipelineand above ground piping shall be of such purity levelas to satisfy the acceptance criteria for residual oxygencontent as specified in 6.2.5.2. Nitrogen gas at ambienttemperature (not liquid nitrogen) and in compressed,vap-orized and gaseous state shall be used as theinertising medium. In case the source of gaseousnitrogen is from liquid nitrogen tankers, then allprecautions (including verification of the lowesttolerable temperature of all components in the systemunder commissioning) should be ensured. Dueprecautions in working with and in releasing ofnitrogen shall be undertaken.


Inertiiation of the pipeline may be accepted if therequired quantity of nitrogen with adequate numberof batching pigs has been introduced into the pipeline.For above ground piping at dispatch and receiptstations, sectionalizing valve stations, intermediatepigging station and hook-up/tap-off points, theinertisation maybe accepted when the residual oxygencontent in the piping-is below 1 percent (vol/vol).

6.2.6 Gas-in and Commissioning

6.2.6.1 Operational requirements

During the introduction of natural gas into the pipeline,the gas shall be the motive fluid for driving the last pigof the nitrogen slug train. The pig train speed shall bemaintained at 3 to 4 kmlh. Maintenance of properback pressure shall control pig train speed. Ventingshall be controlled at the-pig-receiving end to achievethe desired dynamics. The desired portion of thepipeline shall be commissioned in this manner. Thepipeline system shall subsequently be slowlypressurized up to its operating conditions and highpressure leak checks of the pipeline system at flangepoints, instrument points, etc, shall be carried out withsoap solution at regular intervals during the course ofpressurization of the pipeline system. Once the pipelinesystem is pressurized at its operating conditions,normal gas flow shall be established in the pip,elinesystem.

Commissioning shall also include establishing theprocess control parameters and turn down as per thedesign value stipulated. As a part of commissioning,all pipeline monitoring and control equipment shallbe fully function tested, especially safety systems suchas pig-trap interlocks, pressure and flow monitoringsystems, and emergency pipeline shut down systems.Consideration shall also be given to performing a finaltest of pipeline valves prior to the introduction ofnatural gas to ensure that they operate correctly.


The system shall be considered to have beencommissioned successfully when the pipeline systemincluding the under ground pipeline and the aboveground piping at dispatch and receipt stations,sectionalizing valve stations, intermediate piggingstations and hook-upltap-of points is charged withnatural gas, is free of leaks and have run successfullyfor a minimum period of 72 h at stable operatingconditions and instrumentation/control systems,process utilities and support systems taken on line. Thecommissioning of pipeline system shall includecommissioning of branch lines and associated facilitiesincluding auxiliary facilities and above ground piping.

4

IS 15663 (Part 3) :2006

7 DOCUMENTATION

7.1 Commissioning documentation shall includerecords of the following:

a) Pre-commissioning checks;

b) Residual dewatering and swabbing;c) Low pressure leak check of above ground

piping system with dry compressed air;

d) Documents relatedto magnetic cleaningand EGP;

e) Inertisation; and

0 Gas-in and commissioning activities (includingpressurization of pipeline system, high pressureleak check, establishment of flows and 72 hrun).

7.2 All these documents should be prepared coveringall aspects of health, safety and environment (HSE),quality assurance and quality control plans.

5

Bureau of Indian Standards

BIS is a statutory institution established under the Bureau of Indian Standards Act, 1986 to promoteharmonious development of the activities of standardization, marking and quality certification of goodsand attending to connected matters in the country.

Copyright

BIS has the copyright of all its publications. No part of these publications may be reproduced in any formwithout the prior permission in writing of BIS. This does not preclude the free use, in the course ofimplementing the standard, of necessary details, such as symbols and sizes, type or grade designations.Enquiries relating to copyright be addressed to the Director (Publications), BIS.

Review of Indian Standards

Amendments are issued to standards as the need arises on the basis of comments. Standards are also reviewedperiodically; a standard along with amendments is reaffirmed when such review indicates that no changes areneeded; if the review indicates that changes are needed, it .is talcen up for revision. Users of Indian-Standardsshould ascertain that they are in possession of the latest amendments or edition by referring to the latest issue of‘BIS Catalogue’ and’ Standards : Monthly Additions’.

This Indian Standard has been developed from Doc : No. CISD7 (7378).

Amendments Issued Since Publication

Amend No. Date of Issue Text Affected

BUREAU OF INDIAN STANDARDS

Headquarters :

Manak Bhavan, 9 Dahadur Shah Zafar Marg, New Delhi 110002 Telegrams : ManaksansthaTelephones :23230131,23233375,2323 9402 (Common to all offices)

Regional Offices : Telephone

Central : Manak Bhavan. 9 Bahadur Shah Zafar Marz ~ 23237617NEW DELHI 110002 ~ 23233841

.Eastern :

Northern :

Southern :

Western :

1/14 C.I.T. Scheme VII M, V. I. P. Road, Kankurgachi

{

23378499,23378561KOLKATA 700054 23378626,23379120

SCO 335-336, Sector 34-A, CHANDIGARH 160022{

26038432609285

C.I.T. Campus, lV Cross Road, CHENNAI 600113

{

22541216,2254144222542519,22542315

Manakalaya, E9 MIDC, Marol, Andheri (East)MUMBAI 400093 {

2“83292 95,2832785828327891,28327892

Branches : AHMEDABAD. BANGALORE. BHOPAL. BHUBANESHWAR. COIMBATORE. FARIDABAD.GHAZIABAD. GUWAHATI. HYDERABAD. JAIPUR. KANPUR. LUCKNOW. NAGPUR.NALAGARH. PATNA. PUNE. RAJKOT. THIRUVANA-NTHAPURAM. VISAKHAPATNAM.

?mted at Prabhat Otlset Press,”New Delhi-2