Manual. Standards WOC HSE WOC LP. 1 tel) ( W. McIntosh. WO Executive Vice President Operations DOCUMENT NO: WOC-HSE-ST Section H003 Hot Tapping

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1 1_91,,(16,.. r - A. 4 On. c WOC LP & EP Department WOC HSE Standards Manual DOCUMENT NO: WOC-HSE-ST-0001 Section H003 Hot Tapping REV ISSUE PREPARED BY REVIEWED BY APPROVED BY ISSUE DATE 0 Issued for Use!.1v/A 1 tel) ( W. McIntosh LP & EP Manager WO Executive Vice President Operations June 2009

2 41141-,i-ip,,. Ayttiy.9.4- ot,,-- c - Hot Tapping WOC-HSE-ST June of 12 PURPOSE To outline the practices required to safely perform a hot tap into a "live" line or equipment without blinding or purging of equipment. APPLICATION All WAHA worksites and facilities DEFINITION Hot tapping is the technique of attaching a mechanical or welded branch fitting to piping or equipment in service, and creating an opening in that piping or equipment by drilling or cutting a portion of the piping or equipment within the attached fitting. Therefore, this work mainly covers welding technique without a process stream shut down, as it is impractical to take the piping or equipment out of service. Note: It should be noted that Hot-Tapping is not be implemented as a means of convenience. A formal risk assessment shall be performed and Hot-Tapping should be done as a last resort. This information shall be documented and signed off by the Area Superintendent prior to Hot-Tapping taking place. POTENTIAL HAZARDS welding burns and radiation fire and explosion toxic welding vapors 5. REQUIREMENTS 5.1. General Hot tapping is restricted to carbon steel piping systems. Plant systems are governed by rules established by ASME, B-31.3, Chemical and Petroleum Piping Systems or government regulation. Pipeline systems follow the requirements of API 1104, and API RP 2201 Procedures for Welding or Hot Tapping on Equipment in Service as a minimum.

GIs.... Is. 4 O,, Hot Tapping WOC-HSE-ST-0001 0 June 20

A copy of this form must be forwarded to Operations personnel responsible for this area for approval. This approval must be obtained before the hot tap is started.

3 GIs.... Is. 4 O,, Hot Tapping WOC-HSE-ST June of Before undertaking a hot tap, Form A, "Request to Proceed with a Hot Tap," must be completed and approved by the area Operations Manager and engineering. A copy of this form must be forwarded to Operations personnel responsible for this area for approval. This approval must be obtained before the hot tap is started. It should be noted that within this request to Hot Tap Pipeline form a Work Pack is included that contains all the relevant job details such as scope of work, normal operating pressure and temperature, specific product in pipeline, pipeline flow velocity, QA/QC procedures, P & Ids, plus hot tap engineering calculations. In addition to this a comprehensive risk assessment using a Job Safety Analysis (JSA) process must be carried out and attached with all the relevant potential hazards identified and the method of control to remove or mitigate these hazards are fully understood by all parties Form B, "Hot Tap Check List," must be completed and signed off by the Company (WAHA) representative in charge of carrying out the hot tap. This information should be retained as QC documentation by the Operations Manager Waha employees carry out hot tapping operations, however, If a competent Contractor carries out the hot tap, they shall have a Manual, which contains a Safe Operating Practice describing the procedure for operating hot tap equipment, Quality Control manual, Welding Procedure Specification for the materials to be welded, and Welder Certificate for the welder that will execute the hot tap. The welder shall be thoroughly familiar with the welding equipment and hot tap and welding procedures to be used Competent Company representatives including HSE representative must be present during execution of the hot tapping Suitable fire extinguisher shall be available The location to be hot tapped must have be identified and physically marked.

). ''.q 0,, ' Hot Tapping WOC-HSE-ST-0001 0 June 2009 4 of 12 5.1.8. All necessary gas and toxicity tests has been made to ensure a safe environment that is free from flammable substance. 5.1.9. Signs and barriers have been provided to isolate the job area from the public and unauthorized personnel.

This procedure shall indicate isolation points and response by rescue and fire-fighting units. 5.1.12. Prior to the hot tap, the inspector shall ensure the fittings, valves, gaskets and bolting, etc.

4 ). ''.q 0,, ' Hot Tapping WOC-HSE-ST June of All necessary gas and toxicity tests has been made to ensure a safe environment that is free from flammable substance Signs and barriers have been provided to isolate the job area from the public and unauthorized personnel Appropriate personnel protective equipment shall be used Written emergency procedures specific to the job are required in the event of failure. This procedure shall indicate isolation points and response by rescue and fire-fighting units Prior to the hot tap, the inspector shall ensure the fittings, valves, gaskets and bolting, etc., are identified and meet all the required specifications for pressure, temperature and service environment Limitations The minimum pipe wall thickness for hot tapping plant piping shall be 6.4 mm (1/4") & 4.8 mm (3/16") for pipelines. The base metal to be hot tapped shall be properly inspected for adequate wall thickness and the absence of imperfections such as laminations, hydrogen attack, or stress corrosion cracking. Imperfections, which might prevent a sound weld from being made, shall be evaluated by qualified NDT personnel The hot tap shall be at least 3" ( cm) to a welded seam (including a longitudinal seam of welded piping), or 18" (46 cm) to a flange or threaded connection. Other spacing distances must be reviewed and approved by Facilities Engineering If a hot tap is installed upstream of rotating equipment or control valves, strainers or other devices must be in place to prevent damage from metal shavings.

- 1,1 1'4 0, c..= _ Hot Tapping WOC-HSE-ST-0001 0 June 2009 5 of 12 5.2.4. Welding electrodes shall be limited to the low hydrogen type & as specified in the WPS.

4 mm) or smaller diameter welding electrode. 5.2.4.2. The subsequent weld passes be made with 1/8" (3.2 mm) diameter welding electrode, or smaller if the metal wall thickness does not exceed 1/2" (12.

5 - 1,1 1'4 0, c..= _ Hot Tapping WOC-HSE-ST June of Welding electrodes shall be limited to the low hydrogen type & as specified in the WPS. In order to eliminate the occurrence of burn-through, the following steps shall be followed: The first weld pass less than 1/4" (6.4 mm) thick shall be made with 3/32" (2.4 mm) or smaller diameter welding electrode The subsequent weld passes be made with 1/8" (3.2 mm) diameter welding electrode, or smaller if the metal wall thickness does not exceed 1/2" (12.8 mm). The larger diameter electrodes may be used for metal wall thickness greater than 1/2" (12.8 mm) Welding on compressed air lines under pressure is not allowed No Hot-Tapping shall take place on piping systems known to have a vapor/air or vapor/oxygen content as the heat from welding may cause a vapor mixture to enter the flammable range Hot tapping stress relieved piping systems is not allowed. Under special circumstances, approval to hot tap a stress relieve system may be granted by WAHA management provided job specific welding procedures have been developed When the metal wall thickness is greater then what code will allow without having stress relieving performed, Facilities Engineering shall be contacted so as a thorough engineering evaluation may be performed. Max thickness for most piping systems is 19mm (3/4") without PWHT Cooling period shall be included between the completion of the fullencirclement fillet weld and the completion of nondestructive testing. The cooling period after welding and before testing provides for the assessment of any delayed hydrogen-induced cracking. The length of time for the cooling

-.:-, * h4 fly' oft GO Hot Tapping WOC-HSE-ST-0001 0 June 2009 6 of 12 period should be evaluated for each hot tap and approved by Engineering and the Chief Inspector. 5.2.4.8.

$refractory, plastic, or strip linings. 5.2.4.9. Overheating of liquids and burn-through conditions during the welding of a branch connection for a Hot-Tap is less likely when flow is maintained.$

6 -.:-, * h4 fly' oft GO Hot Tapping WOC-HSE-ST June of 12 period should be evaluated for each hot tap and approved by Engineering and the Chief Inspector Unless specifically authorized by specialized procedures or following an engineering evaluation, hot tapping is not permitted on in-service lines or equipment with cladding, or with glass, lead, refractory, plastic, or strip linings Overheating of liquids and burn-through conditions during the welding of a branch connection for a Hot-Tap is less likely when flow is maintained. However too high of flow velocity increases the weld cooling rate and the risk of cracking. Therefore, it is desirable to provide minimum level of flow if possible. Minimum of 1.3ft/sec flow velocity in a gas line shall be maintained to provide sufficient heat transfer. A maximum flow velocity does not appear critical within the limits of practicability in a gas line. In liquid lines, the recommended flow velocity range is ft/sec Maximum Operating Pressure During Hot Tapping In order to avoid the occurrence of burn-through during hot tapping, the operating pressure in the pipeline shall be maintained at pressures not exceeding its critical level by considering that the Heat Affected Zone (HAZ) reduces the strength of metal The MAOP can be calculated using the related ASME formulas (B31.3 for plant piping, B31.4 for liquid lines and B31.8 for gas lines) with considering correction factors as described below: The base metal wall thickness (t) should be reduced by the depth of HAZ. Due to there are no data available yet for the depth of HAZ, it is recommended to consider as 60% of wall thickness for plant piping, and 30% for cross country pipelines either gas or liquid services. One laboratory test/ experiment showed that depth of HAZ is about 4.4 mm (0.13") for the following welding parameters: base metal of 8" dia.pipe

..., 410V ni.60,),, et"..._ ---,,, 4 ori Hot Tapping WOC-HSE-ST-0001 0 June 2009 of 12 sch.40 API 5L gr.b and a plate of 9 mm thick, ASTM-52 gr.50, 3.2 mm dia.

4. Nondestructive Examination LMT = (T2 T1)/ Ln T2/T1 Where, T1 is the temperature of fluid in the pipeline/piping. T2 is the temperature of metal at HAZ, assumed 50 deg C. 5.4.1. Prior to welding, the hot tap location shall be verified for thickness and checked for laminations and other defects using ultrasonic examination methods.

7 ..., 410V ni.60,),, et"..._ ---,,, 4 ori Hot Tapping WOC-HSE-ST June 2009 of 12 sch.40 API 5L gr.b and a plate of 9 mm thick, ASTM-52 gr.50, 3.2 mm dia. Electrodes AWS E-018, DCRP, Amperes, and Volts The specified minimum yield strength of base metal should be determined based on the LMT (log mean temperature) as calculated below, 5.4. Nondestructive Examination LMT = (T2 T1)/ Ln T2/T1 Where, T1 is the temperature of fluid in the pipeline/piping. T2 is the temperature of metal at HAZ, assumed 50 deg C Prior to welding, the hot tap location shall be verified for thickness and checked for laminations and other defects using ultrasonic examination methods After completion of welding, the final weld shall be visually examined and subjected to magnetic particle or dye penetrant examination All Hot Tap connections will be subjected to a hydro test prior to the cutting out of the coupon. 6. REFERENCES API Publication 2201 API RP 4

i:-itil n- rn ti ' q ' -OIL CO Hot Tapping WOC-HSE-ST-0001 0 June 2009 8 of 12 Form A - Request to Hot Tap Pipeline Date of Request: WAHA QC # Purpose

: MOP during hot tap (calculated): Psig Operating Pressure : Psig F Product in pipeline: Pipeline Velocity: Ft/second Description of branch pipe: Hot

8 i:-itil n- rn ti ' q ' -OIL CO Hot Tapping WOC-HSE-ST June of 12 Form A - Request to Hot Tap Pipeline Date of Request: WAHA QC # Purpose of Hot Tap: Length of cooling period: Location: Description of run pipe: Pipeline No.: MOP during hot tap (calculated): Psig Operating Pressure : Psig F Product in pipeline: Pipeline Velocity: Ft/second Description of branch pipe: Hot Tap Contractor - Procedures Manual : Welding Contractor - Quality Control Manual - Welder MIGAS Certified WPS# Work Pack Complete JSA Done Approved :Operations Manager Approved by: Engineering Approved by: QC Personnel

$\--ri o" Hot Tapping WOC-HSE-ST-0001 0 June 2009 9 of 12 Form B - Hot Tap Check List (To be completed by WAHA job supervisor and filed with Quality Control - Hot Taps) Has the properly approved work$ permit been obtained? Has the hot work permit been obtained? Does the company carrying out the welding and hot tapping procedure have an approved QC Manual?

permit been obtained? Has the hot work permit been obtained? Does the company carrying out the welding and hot tapping procedure have an approved QC Manual?

9 x-.1 N., e, - its iii,. \--ri o" Hot Tapping WOC-HSE-ST June of 12 Form B - Hot Tap Check List (To be completed by WAHA job supervisor and filed with Quality Control - Hot Taps) Has the properly approved work permit been obtained? Has the hot work permit been obtained? Does the company carrying out the welding and hot tapping procedure have an approved QC Manual? Has the exact location on the line been identified and marked? Has the location been inspected for thickness and imperfections or defects? Has the pipeline material been identified and is it compatible with the connecting fittings? Is stress relieving required? Do the flanges, bolts, gaskets, pipe, valves and fittings meet the piping code of the line to be hot tapped? Is the hot tap machine correct pressure rating and has it been tested? Is there sufficient external clearance to accommodate the operation of the hot tap machine? Is there sufficient internal clearance to retract the cutter through the valve? Is the hot tap fitting of the proper length to accommodate the operation of the hot tap machine? Have combustible and toxic gas tests been conducted in the area of hot tapping? Will the contents of the line affect the metallurgy of the pipe during the welding operation? Is the material in the line stable under heated conditions and free of oxygen? Has fire-fighting equipment been provided? Has suitable protective equipment been provided for all exposed personnel in the Yes H I I q I I No n H I I

OW v--,41..----- 0,, c 09 Hot Tapping WOC-HSE-ST-0001 0 June 2009 10 of 12 hot tapping area?

10 OW v--, ,, c 09 Hot Tapping WOC-HSE-ST June of 12 hot tapping area? Is there adequate hoisting and support equipment for the hot tapping machine and other equipment as well as room for operational and emergency access? In the event of an emergency incident occurring during the hot tapping operation, has a procedure to isolate the work area been prepared and are personnel trained to implement this procedure? _ q Date: Print Name: Signature: WAHA QC#

114V 5,0) ' es -4 w w; Wilitap 444 c,! -,-,, Hot Tapping WOC-HSE-ST-0001 0 June 2009 11 of 12 SAMPLE OF CALCULATION SHEET Plant piping (Refer to ANSI/ASME B31.3). Pipe material: 6.625" OD x 0.

3 ft/sec is OK) Base metal thickness measured at hot tap point, 0.25" Depth of HAZ (assume 60%): 0.6 x 0.25" = 0.

11 114V 5,0) ' es -4 w w; Wilitap 444 c,! -,-,, Hot Tapping WOC-HSE-ST June of 12 SAMPLE OF CALCULATION SHEET Plant piping (Refer to ANSI/ASME B31.3). Pipe material: 6.625" OD x 0.25" wall thickness, API 5L Gr.B. Content: Liquid hydrocarbon Internal pressure: 150 psi Flowing temperature: 200 deg C Flow velocity: 0 cm/sec (2.3 ft/sec is OK) Base metal thickness measured at hot tap point, 0.25" Depth of HAZ (assume 60%): 0.6 x 0.25" = 0.15" Temperature of metal at base of HAZ; assume 50 deg C Corrected base metal thickness 0.25" 0.15" = 0.10" Corrected OD: 6.625" 2(0.15") = 6.325" LMT = (50 200)/ Ln(50/200) deg C = 41 deg C = 82 deg F Allowable stress at this temperature, S = 11,000 psi. Apply hoop stress formula from ANSI/ASME B31.3, P = 2 t S/ (D 2 y t), y for temperature below 900 deg F is 0.4 = 2 x 0.10 x 11,000 / ( (0.4 x 0.10)) psi = 336 psi Since the internal pressure of piping is only 150 psi, which is far below the max. allowable operating pressure of 336 psi, hot tapping can be done safely.

,,4 OIL C Hot Tapping WOC-HSE-ST-0001 0 June 2009 12 of 12 SAMPLE OF CALCULATION SHEET Cross country gas pipeline (Refer to ANSI/ASME B31.8). Pipeline material: 18" OD x 0.

12 ,,4 OIL C Hot Tapping WOC-HSE-ST June of 12 SAMPLE OF CALCULATION SHEET Cross country gas pipeline (Refer to ANSI/ASME B31.8). Pipeline material: 18" OD x 0.35" wall thickness, API 5LX X52. Content: Natural gas Internal pressure: 1,200 psi Flowing temperature: 15 deg C Flow velocity: greater than 5 ft/sec Base metal thickness measured at hot tap area: 0.40" Depth of HAZ is assumed 30% x 0.40" = 0.12" Corrected wall thickness: 0.40" 0.12" = 0.28" Corrected diameter: 18" 2 (0.12") = 1.2" Temperature at HAZ is assumed: 50 deg C LMT = (50 15)/ Ln(50/15) = 188 deg C Allowable stress at this temperature is 28,600 psi. Maximum allowable operating pressure during hot tapping, P = 2 t S/ D = 2 x 0.28 x 28,600/ 1.2 = psi. This calculation concludes that in order to execute hot tapping safely, the operating pressure of the gas line should be reduced from 1,200 psi to 900 psi or lower.

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