SAFETY Rev. 1 - Q-Chem Internet · JSA – Job Safety Analysis ... Purging, Venting, ... If the...

SAFETY HSE-SAF-PRO-00-0029

Rev. 1

OPENING OF PROCESS EQUIPMENT OR PIPING

29-Jan-2014

of 26

HSE-SAF-PRO-00-0029 Page 1 of 26

TABLE OF CONTENTS

1. INTRODUCTION ...................................................................................... 2

2. SCOPE & PURPOSE ............................................................................... 2

3. DEFINITIONS ........................................................................................... 2

4. OPENING OF PROCESS EQUIPMENT OR PIPING ............................... 3

5. RESPONSIBILITIES .............................................................................. 12

6. REFERENCES ....................................................................................... 12

7. ATTACHMENTS .................................................................................... 12

8. APPENDICES ........................................................................................ 13

Rev. Issue Date Amendment Description Prepared by Reviewed by Approved by

1 29-Jan-14 Amendment to Section 4.9 (x) (a), Appendix A and Appendix D (ii) (c)

R. Bartolome Arantelo Abreu

C. Poldrack

0 01-Jun-13 New Document R. Bartolome Safety C. Poldrack

Next Scheduled Periodic Review: June/2016


Rev. 1


29-Jan-2014

of 26


1. INTRODUCTION

This procedure is developed for the use of operators and other equipment owners while preparing equipment for maintenance. This is also intended to provide basic guidelines for maintenance personnel performing line or equipment opening. Process equipment and piping contain hazardous materials and/or hazardous energy. Inadequate preparation prior to line or equipment opening can lead to a process safety event. From a regulatory standpoint, this serves as a safe work practice as required by Section (f)(4) of the OSHA PSM Standard 29 CFR 1910.119.

2. SCOPE & PURPOSE

This procedure applies to the process units at the Q-Chem manufacturing facilities in Mesaieed and Ras Laffan. This is intended for use mainly in the preparation for the opening of process equipment or piping as part of normal maintenance activities. Although these steps generally apply for all situations, additional hazard analysis may be required when using this procedure under abnormal conditions.

3. DEFINITIONS

CCCW – Closed Circuit Cooling Water

First Break – The part of a line break which involves the actual opening of the first connection joint in the equipment or system.

i. For flanges or connection joints with 16 bolts or more – first break is considered as the removal of any of the last eight bolts. Refer to Appendix E for bolting configuration.

ii. For flanges or connection joints with less than 16 bolts – first break is considered as the removal of any of the last four bolts. Refer to Appendix E for bolting configuration.

iii. Loosening of threaded connections.

IDLH – Immediately Dangerous to Life or Health is an atmosphere that poses an immediate threat to life, cause irreversible adverse health effects, or would impair an individual’s ability to escape from a hazardous atmosphere.

JSA – Job Safety Analysis

Line Break – The separation of mating components such as flanges or unions, unscrewing of threaded connections, or disassembly of other equipment components (i.e. man ways, hand holes, etc.).

LEL – Lower Explosive Limit the lowest concentration of flammable or combustible vapour in air that will propagate flame in the presence of an ignition source.

LT&T : Lockout Tagout & Try

MDMT: Minimum Design Metal Temperature

PRD – Pressure Relief Device

PRV – Pressure Relief Valve


Rev. 1


29-Jan-2014

of 26


P&ID – Piping and Instrumentation Diagram

RD – Rupture Disc

SABA – Supplied Air Breathing Apparatus

SCBA – Self Contained Breathing Apparatus

4. OPENING OF PROCESS EQUIPMENT OR PIPING

4.1. General

i. No attempt shall be made to open process equipment or piping until all preparatory work is completed as described in the succeeding sections.

a) The loosening or removal of any one bolt in the flange or connection joint, or the loosening of a threaded connection, is considered as the start of a line break.

ii. Prior to attempting line breaks, bolt conditions shall be checked to ensure bolt removal and subsequent line/vessel opening can proceed as planned.

4.2. Taking Equipment Out of Service

i. The equipment owner shall perform shutdown operations on the affected equipment as

specified in the applicable operating procedures.

ii. In circumstances where line break on piping or equipment connected to a live flare system, systems with passing valves, or systems with an unknown atmosphere is absolutely necessary, the requirements of Appendix A shall apply.

4.3. Purging, Venting, and Draining

i. Once shutdown operations are completed, the equipment owner shall prepare and line-up

the equipment for venting/depressurization or draining. a) Purging, venting, and draining present some hazards if not done properly. Refer to

Appendix B prior to starting these activities to identify and mitigate the applicable hazards.

b) Where applicable, provide grounding and/or bonding as specified in the Bonding and Grounding Standard (HSE-SAF-STD-00-0047).

ii. Vent/depressurize or drain the equipment through the appropriate route and with the

appropriate tools.

a) Where a hose is required, ensure that its specifications are appropriate for the intended service.

b) When draining/venting liquid hydrocarbons, ensure that the rate is controlled to prevent cooling of the equipment below its Minimum Design Metal Temperature (MDMT) and avoid cold brittle fracture.

c) When draining into drums or other containers, ensure the following:

The need for a Job Safety Analysis (JSA) is evaluated, and the analysis is conducted where required.


Rev. 1


29-Jan-2014

of 26


Drums or containers are labelled and are compatible with the material being drained.

The equipment and the containers are properly grounded/bonded.

There are no ignition sources, including all hot work, within a 15-meter radius of the draining operation.

Continuous gas monitoring, within a 15-meter radius, is performed for the duration of the draining operation and the activity is stopped whenever the LEL exceeds 10%.

iii. Ensure that the equipment is completely vented/depressurized and/or drained.

a) If system cannot be completely depressurized, verify isolation and ensure that all valves are fully closed.

b) Make a note of low points or dead legs in the system to ensure that these are addressed during the purging step.

c) Verify line-up of instrument impulse lines to ensure that these are also clear of residual material and/or energy.

iv. If the equipment is in non-hazardous material service and has no possibility of

contamination, skip the succeeding steps and proceed with the application of LT&T devices.

v. If the equipment is in hazardous material service or has a possibility of contamination,

proceed with purging as described in the succeeding steps.

a) Certain conditions (i.e. residual solids, corrosive service, pyrophoric service, reactive catalyst, etc.) may require additional or alternative methods of purging, refer to Appendix B.

vi. Confirm the design pressure of the equipment to be purged. For systems with multiple

components, take note of the lowest design pressure.

vii. If the equipment design pressure is lower than the Nitrogen supply pressure, do not perform purging directly. Ensure that the following precautions are in place:

a) A calibrated pressure regulator is installed to let down the Nitrogen pressure to 50% of

the equipment design pressure. A typical set-up is shown below:


Rev. 1


29-Jan-2014

of 26


b) Provision for pressure monitoring is available either through a pressure indicator in the system, or a local gauge installed in an appropriate location.

c) A Pressure Relief Device, set to relieve below the equipment design pressure, is available either through a PRV/RD in the system, or a temporary PRD installed in an appropriate location.

If the system does not have any provisions for pressure relief, a detailed procedure to avoid an overpressure scenario specific to the purging operation shall be developed. This procedure shall be approved by the shift coordinator (Q-Chem only) or a shift supervisor from another area.

viii. At the designated purge inlet point, attach a check valve and a Nitrogen supply hose.

ix. Open the Nitrogen into the equipment and allow the system to pressurize to the

designated pressure.

x. When the system reaches the designated pressure, block in the Nitrogen supply and check for leaks.

xi. Open the vent to flare and allow the system to depressurize.

xii. When the system is depressurized, initiate the Nitrogen pressurization process again.

a) The pressurization / depressurization cycle shall be done at least three times.

b) Ensure that all components of the equipment, especially low points and dead legs, are covered in the purging circuit.

c) After the third cycle, measure the LEL at an appropriate vent point.

xiii. If LEL is still above 10%, continue purging to the flare. Once LEL is below 10%, purging can be routed to the atmosphere.

xiv. Purging, venting, and draining shall be performed as described in Appendix B.


Rev. 1


29-Jan-2014

of 26


4.4. Gas Testing

i. The equipment owner shall check the internal atmosphere of the piping and/or equipment flammables and toxic gases to monitor and ensure the effectiveness of the purging process.

a) Purging and gas testing shall continue until the desired conditions for the initial line break are reached as follows:

LEL is 10% or less

H2S concentration is less than 50 ppm

Concentration of other toxic material(s) is less than 50% of its IDLH.

ii. Conduct the test within the internal space wherever there are available bleeder valves as shown in the figure below. Use available bleeders only, do not crack open flanges for testing prior to the initial line break.


Rev. 1


29-Jan-2014

of 26


iii. To ensure accuracy of gas testing results, the tests shall be performed only by an authorized gas tester as per the general sampling requirements in Appendix C.

4.5. Application of Lockout/Tagout & Try Devices (LT&T)

i. The equipment owner and maintenance personnel shall install LT&T devices as per the applicable isolation list(s) and in accordance with the Lockout, Tagout, and Try Procedure (HSE-SAF-PRO-00-0004).

a) Ensure the appropriate isolation list is used for the activity. Initial line break shall not be allowed without completion of the energy isolation process.

b) A table showing approved methods of isolation is shown below:

Isolation Type and Work Category

General Work

Hot Work Confined

Space

Drop-out Spool Yes Yes Yes

Blind Flange Yes Yes Yes

Single Block Valve Yes No No

Double Block and Bleed Yes Yes No

c) A single proven non-passing valve is an acceptable isolation, if isolation methods as

per the above table are not feasible, for hot work on lines having instrument air, plant air, low pressure steam (< 3.5 Kg/cm2), Nitrogen (< 9 Kg/cm2), fresh water, potable water, polished water, demineralised water, sea water, fire water, Closed Circuit Cooling Water (CCCW), and pellet transfer lines. However, the following conditions shall apply:

This shall be agreed between Shift Coordinator (or Other Area Shift Supervisor) and Shift Supervisor by co-signing the isolation list.

http://qedms/NetFYI/cgi/NetFYIIsapi.DLL?Method=AddLogin+RetrieveDoc&L=L&DSN=FYI&UserID=RO&PASSWORD=RO&C=Plant%20Information--RO&F=150&D=268718


Rev. 1


29-Jan-2014

of 26


For hot work on instrument air and Nitrogen lines, personnel within the fire box shall carry an Oxygen monitor.

For hot work on CCCW and pellet transfer lines, the HC level shall be ensured to be zero, prior to the start and for the duration of the job.

4.6. First Break

i. The equipment owner shall assess the risks of first break relative to the service, the

configuration, and other factors which may have affected the effectiveness of equipment preparation. A Job Safety Analysis (JSA) shall be conducted where risk is not minimal as described in, but not limited to, the following scenarios:

a) The dissipation of energy and residual material cannot be positively proven.

b) There is historical evidence of difficulty in dissipating energy and/or clearing of residual material in the equipment.

c) There is no prior experience with the particular first break location.

d) The first break location may contain an unstable or unknown residue.

ii. The equipment owner shall mark the flange or connection joint to positively identify each line break location.

iii. The equipment owner and maintenance personnel shall jointly perform the following

confirmation steps shortly before removing alternate bolts in the connection joint. Appendix E illustrates some recommended alternate bolting sequences.

a) Confirm that LT&T is complete. b) Confirm and verify that the equipment is fully vented, drained, or emptied out.

Where applicable, the JSA is complete and all mitigating measures are in place.

Where required, a means for quick and safe egress from the work area is available.

c) Alternate bolting shall not start if any of the above conditions are not satisfied.

iv. The equipment owner shall be present when removing the first bolt for alternate bolting to provide verification of the correct location to the maintenance personnel.

a) Equipment owner presence is intended for onsite confirmation of the line break location only. He/she does not need to be in the work area for the full duration of the task.

v. The maintenance personnel shall proceed with the removal of alternate bolts on the

disconnection joint prior to first break.

a) First break is the actual opening of the first flange or connection joint in the affected equipment.

For flanges or connection joints with 16 bolts or more – first break is considered as the removal of any of the last eight bolts. Refer to Appendix E for bolting configuration.

For flanges or piping connection joints with less than 16 bolts – first break is considered as the removal of any of the last four bolts. Refer to Appendix E for bolting configuration.


Rev. 1


29-Jan-2014

of 26


Loosening of threaded connections.

vi. Prior to first break, the equipment owner and maintenance personnel shall ensure that all additional requirements and precautions are in place. These include, but are not limited to, the following:

a) The internal atmosphere in the equipment is within the following limits:

LEL is 10% or less

H2S concentration is less than 50 ppm

Concentration of other toxic material(s) is less than 50% of its IDLH

b) Self Contained Breathing Apparatus (SCBA) or Supplied Air Breathing Apparatus (SABA) shall be used as respiratory protection for the first-break of any line containing or previously containing traces of H2S or other toxic material(s) irrespective of gas test results.

c) SCBA or SABA shall be used as respiratory protection for the first-break of any piping or equipment that is under positive Nitrogen pressure not exceeding 0.2 kg/cm2.

Line breaks are not allowed on lines under positive Nitrogen pressure greater than 0.2 kg/cm2.

d) The equipment owner shall also be present at first break to provide verification of the correct location.

Equipment owner presence is intended for onsite confirmation of the first break location only. He/she does not need to be in the work area for the full duration of the task.

vii. The maintenance personnel shall perform the first break on the equipment.

a) Break flanges/joints “down and away” or out of the line of fire.

b) If residual pressure or material is observed, retighten bolts, and re-evaluate the conditions. Do not proceed until it is confirmed that the equipment is ready for opening.

viii. After successful completion of first break, subsequent line breaks may now be made

within the boundaries of the original isolation and preparation.

a) SCBA or SABA shall still be required for performing these on piping or equipment under positive Nitrogen pressure.

b) SCBA or SABA shall also still be required for equipment in toxic service if gas test results show an increasing trend even if they were within acceptable limits at the start of the activity.

4.7. Blinding and Deblinding

i. Certain work activities require blinding and/or deblinding. The requirements of the

preceding sections shall be followed whenever the installation or removal of a blind is the first line break in the equipment or piping circuit.

ii. In addition, all blinding and deblinding activities shall also adhere to the requirements specified in Appendix D.


Rev. 1


29-Jan-2014

of 26


4.8. Box-Up and Reinstallation

i. The equipment owner shall work with maintenance personnel to box-up all line breaks and openings, and reinstall any equipment that may have been removed.

ii. All box-up and reinstallation activities shall be conducted in accordance with applicable

standards and safe work practices.

4.9. Oxygen Freeing

i. The following steps shall be followed where Oxygen-freeing and inerting is required prior to taking equipment back in service.

ii. Ensure all line breaks and vessel/equipment openings have been properly boxed-up.

iii. Line-up the system for Oxygen freeing operations.

a) A marked-up P&ID showing the locations of the Nitrogen source and the vent points shall be prepared and made available for the duration of the activity.

b) Vents, drains, and bleeders that are not used in the activity shall be closed and plugged/capped.

iv. Confirm the design pressure of the equipment to be purged. For systems with multiple

components, take note of the lowest design pressure.

v. If the equipment design pressure is lower than the Nitrogen supply pressure, do not perform purging directly. Ensure that the following precautions are in place:

a) A calibrated pressure regulator is installed to let down the Nitrogen pressure to 50% of the equipment design pressure. A typical set-up is shown below:

b) Provision for pressure monitoring is available either through a pressure indicator in the system, or a local gauge installed in an appropriate location.

c) A Pressure Relief Device, set to relieve below the equipment design pressure, is available either through a PRV/RD in the system, or a temporary PRD installed in an appropriate location.


Rev. 1


29-Jan-2014

of 26


If the system does not have any provisions for pressure relief, a detailed procedure to avoid an overpressure scenario specific to the purging operation shall be developed. This procedure shall be approved by the shift coordinator (Q-Chem only) or a shift supervisor from another area.

vi. At the designated purge inlet point, attach a check valve and a Nitrogen supply hose.

vii. Open the Nitrogen into the equipment and allow the system to pressurize to the

designated pressure.

viii. When the system reaches the designated pressure, block in the Nitrogen supply and check for leaks.

ix. Open the designated atmospheric vent(s) and allow the system to depressurize.

a) Ensure that vent(s) are in a safe location away from personnel traffic. Where required, barricade the vent location(s).

b) Do not route vents to the flare header if Oxygen content is greater than 0.5%.

x. Perform the pressure-depressure cycle repeatedly until the targeted Oxygen level is reached.

a) Use properly calibrated portable gas detectors to measure the Oxygen content in the system.

b) If necessary, the vent can be routed into the flare header once the Oxygen level is less than 0.5%.

xi. After completing the activity, ensure the following:

a) All hoses, fittings, and other piping components used for Oxygen freeing have been disconnected from the equipment/system.

b) All vents, drains, and bleeders are closed and plugged/capped.

4.10. Removal of Lockout/Tagout & Try Devices (LT&T)

i. The equipment owner shall remove Lockout/Tagout & Try devices as per the applicable isolation list(s) and in accordance with the Lockout, Tagout, and Try Procedure (HSE-SAF-PRO-00-0004).

ii. The equipment owner shall remove the LT&T devices.

4.11. Taking Equipment Back in Service

i. The equipment owner shall verify that the equipment/system is completely boxed-up and ready for commissioning and start-up.

a) Marked-up P&IDs used during the activities (e.g. LT&T, blinding, purging, Oxygen freeing, etc.) shall be used as a reference to determine that all work is complete and the equipment is ready for start-up.

b) For isolations involving more than 10 locks, the Pre-Startup Checklist (Attachment D)

shall be used to perform the verification and preparation for start-up. For other




Rev. 1


29-Jan-2014

of 26


isolations requiring 10 locks or less, it is recommended to use the same checklist for verification.

4.12. Training

i. All production, maintenance, and safety personnel shall receive training on this safe

work practice as specified in the Global Training Matrix.

4.13. System Performance Assessment

i. This procedure, and its associated training program, shall be reviewed for effectiveness, and revised for continuous improvement at least every three years.

5. RESPONSIBILITIES

5.1 Equipment Owner – The equipment owner shall be responsible for ensuring that equipment is prepared for maintenance, and taken back into service according to the requirements of this procedure, and any additional measures specified in the hazard analysis.

5.2 Maintenance Personnel – Maintenance personnel involved in the opening of process equipment shall adhere to the requirements of this procedure, and any additional measures specified in the hazard analysis, when performing their tasks.

5.3 Safety Department – As procedure owner, the Safety Department is responsible for maintaining this document and shall provide oversight and guidance in its implementation. The group shall also be responsible for leading the periodic review and evaluation of the work process.

5.4 Training Department – The Training Department shall coordinate with the Safety Department in developing an effective training program for affected personnel. The group shall be responsible for the delivery of training and evaluation of its effectiveness.

6. REFERENCES

6.1. OSHA Process Safety Management (PSM) Standard 29 CFR 1910.119(f)(4)

6.2. Operational Excellence System Manual, EHS-1100, 3.8.4(c), S3.8.3(b)(14)

6.3. Q-Chem Permit To Work Procedure, HSE-SAF-PRO-00-0006

6.4. Q-Chem Lockout, Tagout, and Try Procedure, HSE-SAF-PRO-00-0004

6.5. Q-Chem Confined Space Entry Procedure, HSE-SAF-PRO-00-0007

6.6. Q-Chem Portable Gas Detector Procedure, HSE-SAF-PRO-00-0008

6.7. Q-Chem Bonding and Grounding Standard, HSE-SAF-STD-00-0047

7. ATTACHMENTS

7.1. Attachment A – Hazard Analysis for Opening of Process Equipment (HSE-SAF-SFM-00-0111)









Rev. 1


29-Jan-2014

of 26


7.2. Attachment B – Written Plan for Opening of Process Equipment (HSE-SAF-SFM-00-0112)

7.3. Attachment C – Line Break Permit (HSE-SAF-SFM-00-0109)

7.4. Attachment D – Startup Checklist (HSE-SAF-SFM-00-0110)

7.5. Attachment E – Q-Chem Blind List (HSE-SAF-SFM-00-0011)

8. APPENDICES

8.1. Appendix A – Line Break on a Live Flare System

8.2. Appendix B – Purging, Venting, and Draining

8.3. Appendix C – General Sampling Requirements for Gas Testing

8.4. Appendix D – Blinding and Deblinding

8.5. Appendix E – First Break and Alternate Bolting Diagrams







Rev. 1


29-Jan-2014

of 26


Appendix A

Line Break on a Live Flare System or Systems with Passing Valves or Systems with Unknown Atmosphere/Content

Opening of piping or equipment that is not positively isolated from energy sources is generally prohibited. However, design (i.e. lack of isolation valves) and/or reliability (i.e. passing valves) issues sometimes prevent the positive isolation of equipment. The use of this procedure shall be considered as a last resort when there are no other feasible alternatives. When utilizing this procedure, the equipment owner shall develop and implement a plan to install, replace, or repair manual valves at the appropriate locations to prevent, or minimize the repetitive need for line breaks on systems that are not fully de-energized. For the purpose of this procedure, the line breaks shall be categorized into three: Live Flare System: Line breaks where the disconnection joint is connected to a live flare system. Systems with Passing Valves: Line breaks where there is residual hazardous energy/material in the disconnection joint due to passing valves. Systems with Unknown Atmosphere/Content: Line breaks where there is no provision for testing the internal atmosphere and/or identifying the residual content of the equipment. Requirements:

i. Prior to considering line breaks in these conditions, the equipment owner shall ensure that there are no other available options to take the system out of service.

ii. The equipment owner shall assemble a team of subject matter experts from the affected

work groups to evaluate the activity. At a minimum, the team shall be composed of representatives from the following:

a. Equipment Owner

b. Maintenance

c. Safety

iii. The team shall review the activity and complete the following: a. A written hazard analysis of the entire process from first break to box-up or

reinstallation (Use Attachment A – Hazard Analysis Template as basic reference). The analysis shall include preventive and/or corrective measures to address the identified hazards.

b. A detailed written plan/procedure (Use Attachment B – Written Plan Template as basic reference) for the entire process which includes:

Specific written sequence of all required actions

PPE requirements

Tools and material requirements

Access/egress conditions

Operational considerations/limitations

Emergency response requirements


Rev. 1


29-Jan-2014

of 26


c. A written communication plan that clearly explains all aspects of the activity and identifies the target audience for sharing the information.

d. A plan to prevent the recurrence of the same situation documented in Section D of the Line Break Permit.

iv. The equipment owner shall compile all relevant documents from the previous steps and obtain the necessary approvals through the Line Break Permit (Attachment C). The Shift Supervisor shall be responsible for originating and coordinating the evaluation and approval process. In case of unavailability, the Operating Specialist may also perform this function.

a. Q-Chem Approvals: Unit Superintendent, Shift Coordinator, Maintenance Manager, Production Manager, Safety Manager.

b. RLOC Approvals: Unit Superintendent, Shift Supervisor from another area, Maintenance Superintendent, HSE Superintendent, Deputy Plant Manager.

v. The approval groups shall review all safety and technical aspects of the activity and provide written approval through the Line Break Permit.

a. When approval authorities are not available onsite for signing the documents, electronic (i.e. e-mail, SMS, etc.) or verbal (i.e. phone) response is acceptable. The time and date of this approval shall be documented on corresponding section of the permit.

vi. After approval, the equipment owner shall coordinate the activity and ensure that all requirements and conditions are complied with.

vii. The equipment owner may keep the relevant documents (i.e. hazard analysis, written

plan, and communication plan) for re-use on the same activity in the future. However, a new permit is required each time the activity is performed.

viii. Completed permits and associated documents shall be kept by the equipment owner for a rolling 12-month period.


Rev. 1


29-Jan-2014

of 26


Appendix B

Purging, Venting, and Draining

i. Hazards of Purging, Venting, and Draining a. Equipment Overpressure

The pressure of utility Nitrogen is 8.5 kg/cm2 in Q-Chem and 11 kg/cm2 in RLOC. Ensure that the equipment being purged is rated for these pressures.

b. Fire and Explosion

When purging hydrocarbons, do not route vents to atmosphere if the LEL is greater than 10%

When Oxygen freeing, do not route vents to flare if Oxygen level is greater than 0.5%.

Where applicable, ensure proper grounding/bonding to prevent static generation. c. Flame Out of Flare Pilots

Ensure purge gas (Nitrogen) flow rates are controlled to avoid extinguishing the flare pilots.

d. Heat or Cold Burns

Use proper PPE when using steam or depressurizing liquid hydrocarbon which flash easily.

e. Vacuum

Ensure equipment is rated for vacuum or relief devices are in service. f. Asphyxiation

Nitrogen purge points shall be directed towards a safe location. Hoses used shall be tagged and secured properly.

g. Cold Brittle Fracture

Control depressurization rates when working with liquids that easily flash and generate low temperatures.

h. Contamination of Dedicated Systems

Use check valves when connecting purge media to process equipment. i. Ethylene Decomposition

Pressurize Ethylene-filled systems slowly. Rapid pressurization can trigger a decomposition reaction that can result in catastrophic failure.

ii. Methods of Purging a. Certain conditions or processes may require the use of a combination of methods to

achieve effective purging. In these circumstances, the equipment owner shall convene a team of subject matter experts to evaluate and identify the most effective option. Examples of these are:

Equipment with solids (i.e. treaters, silos, sludge settlers, etc.)

Equipment in corrosive service

Equipment in pyrophoric service

Equipment with weirs, baffles, or trays.

b. Pressure Cycle Purging (Pressure/Depressure-PDP) – This method requires the system to be pressurized with the purge gas and then the entire contents vented out into a flare header or to the atmosphere if the LEL is below 10%.

This method reduces the partial pressure of flammable gases within the system and may have to be repeated several times to ensure the mixture within the vessel is below the target LEL (< 10%).


Rev. 1


29-Jan-2014

of 26


Based on past experience, using Nitrogen to do PDP is the most effective method of purging. Nitrogen shall be taken from utility stations for this purpose.

For optimum results, at least three PDP cycles are required using Nitrogen as a purge gas.

c. Displacement Purging – This method requires the use of water to completely fill a system and displace flammable vapors and Oxygen.

Water filling is often used to allow welding on tanks which have contained volatile hydrocarbons.

While draining the water, vent shall be opened to avoid vacuum.

d. Steam Cleaning – This method uses steam to volatilize residual flammable liquids and remove scale or other undesirable deposits in the system.

Verify the design specifications of the vessel/system and ensure this operation does not lead to excursions.

The planning process shall ensure that the entire system is heated to a temperature high enough to volatilize the contents of the system and prevent condensation of the steam.

Using steam to clean and purge can cause vacuum that may result in equipment collapse (implosion) when the steam cools over a period of time.

Condensate draining shall be done into a closed system as it potentially contains flammable liquids or toxic materials.

e. Siphon Purging – This method requires the system to be liquid filled and an inert gas is used to displace the liquid as it is drained from the system.

Care shall be taken to ensure the rates of drainage and inert gas introduction match to prevent the generation of excess positive or negative pressure that could damage the equipment.

f. Sweep Through Purging – This method requires the purge gas to be introduced into one end of the system and vented at the other end. The effectiveness of the purge is dependent upon:

the rate of flow of purge gas and the amount of effective mixing

the relative density of the purge gas compared to the density of gas being purged

the direction of purging

dead legs on the system

volume of equipment/piping being purged


Rev. 1


29-Jan-2014

of 26


Appendix C

General Sampling Requirements for Gas Testing

i. The maximum allowed sampling distance of gas detectors fitted with sampling pumps is 100 feet (30 meters).

a. This shall be achieved using either 1/8” or 3/16” urethane tubing only.

ii. The “2x2” sampling rule shall be followed when sampling:

a. Two seconds sampling per foot of tubing used.

b. Two minutes minimum sample time per location.

Example: 20 feet of tubing sample draw time would be 2 minutes and 40 seconds.

iii. Any purging and venting (using mechanical ventilation) shall be stopped for at least 10

minutes prior to conducting gas testing.

a. Exception may be granted if slight purging is required to maintain a slight positive pressure.

b. The Authorized Gas Tester may increase the stoppage time if necessary for larger vessels or equipment.

iv. Do not use gas detectors for measuring flammable gases in an atmosphere with steam.

v. In locations of low Oxygen atmospheres (less than 10% by volume), a dilution tube shall

be attached to the gas detector to obtain a more accurate reading for combustible gases.

a. The dilution tube shall be inserted into the sampling tube at the detector inlet.

b. The dilution tube shall be inserted into the tubing with the directional arrow on the tube pointing towards the detector.

Installation of the dilution tube in the reverse direction shall cause erroneous low readings.

c. The tube will draw a 1:1 ratio of ambient Oxygen with the gas sample being drawn.

d. The action of the dilution tube will elevate the Oxygen readings to a level suitable for accurate combustible gas monitoring.

vi. The following criteria shall be adhered to when using dilution tubes:

a. Use to sample in atmospheres of less than 10% Oxygen by volume.

b. Ambient Oxygen readings shall be between 20-23.5% by volume.

c. Sampling from a vessel/pipe containing a gas mixture exceeding 200% LEL may damage the LEL sensor.

d. Instrument readings will be approximately equal to one half of all gas concentrations being sampled.

Displayed readings shall be multiplied by two (2) to obtain actual concentrations.


Rev. 1


29-Jan-2014

of 26


e. Maximum sampling tube length of 10 feet (3 meters) can be used.

f. The area being sampled MUST be at atmospheric pressure:

Do not use the dilution tube for sampling of positive pressure lines. Operation of the dilution tube in this manner causes an imbalance in the 1:1 ratio thus causing readings to be inaccurate.

Sampling from a negative pressure area will produce a lower than actual reading.

Sampling from a positive pressure area will produce a higher than actual reading.

g. Allow three (3) minutes before reading the concentration.

h. Avoid drawing oil, dust or steam into the dilution tube.

i. Do not clean the air intake hole or sample hole with wire or drill bits that may enlarge the diameter of the holes.

j. Store the dilution tube in a sealed, clean and dust-free container when not in use.

Some examples showing the use and effects of dilution tubes on gas detector readings:

Example 1: A 15% LEL reading on the meter display would actually be 30%.

Example 2: A 10.5% Oxygen reading on the meter display would actually be 0% Oxygen (the 10.5% reading being due to the fresh air draw from the dilution tube).


Rev. 1


29-Jan-2014

of 26


Appendix D

Blinding and Deblinding

i. General Requirements

a. Blinding is mandatory for work involving any of the following:

Confined space entry

Open equipment in hazardous material (e.g. flammables, toxics, corrosives), Nitrogen (≥ 9 kg/cm2), or steam (≥ 3.5 kg/cm2) service left unattended for more than 12 hours

Specific procedural or process requirements (i.e. SOP, SMP, pressure testing, JSA, etc.)

b. Blinding is recommended for work involving any of the following:

Hot work on equipment in hydrocarbon service

Opening of vessels, columns, furnaces or reactors where there is a possibility of hazardous material accumulation

ii. Blind Types

a. Standard Blinds

Standard thickness blinds compatible with the piping/equipment design, and meeting other ANSI design requirements shall be used for isolation purposes.

Standard blinds shall have the size and pressure rating stencilled or steel-stamped on the blind (i.e. 2”-150psi)

Consult the Technical Department for questions or concerns regarding the design specifications of a blind.

b. Non-Standard Blinds

Non-standard blinds shall be used only under all of the following conditions:

Work does not involve pressure testing

Physical configuration of the equipment prevents the use of a standard blind

The equipment/system pressure shall not exceed the rating of the non-standard blind.

The blind handle for non-standard blinds shall be painted with a bright orange paint to allow easy identification and avoid confusing a standard thickness blind with a non-standard blind.

The blind size, pressure rating and thickness shall be stencilled on the blind handle or circumference of the blind (i.e. 12"-180psi-½” t)

c. Plugs and Caps

Standard caps or plugs compatible with the piping/equipment design shall be used in place of blinds for isolation of threaded connections (e.g. instrument air tubings, analyser connections, etc.).

These caps or plugs serve the same purpose as blinds and shall be included in the blind list.

All other relevant procedural requirements for blinds apply to the caps or plugs.


Rev. 1


29-Jan-2014

of 26


iii. Blind List

a. The equipment owner shall develop and maintain a master blind list for applicable equipment and/or systems.

Master blind lists shall be maintained in a controlled manner to prevent inadvertent alterations.

b. Whenever blinding is required for a task, the equipment owner shall reference the master blind list and prepare a list that is applicable to the task. The list shall indicate the following:

Blind location

Size

Type

Sequential numbering as shown in the marked-up drawings

c. The list shall include a marked-up drawing (i.e. P&ID) indicating the blind locations relative to the equipment.

d. The list shall be reviewed and approved by the shift supervisor. If work involves CSE, additional approval from the shift coordinator (Q-Chem) or other are shift supervisor (RLOC) is also required.

iv. Using the Blind Tags and Blind List for Blinding

a. The equipment owner shall verify isolation of each blind location and attaches the

corresponding blind tags.

The equipment owner shall complete the top portion of the tags and signs off the blind list under “OK to Install Blind”.

b. The lead worker shall also verify completion of isolation, confirms each blind location,

and signs off on the blind list under “OK to Install Blind”.

c. After confirming that the equipment is ready for opening, as described in the main section of this procedure, the maintenance personnel shall proceed with the installation of blinds.

Blind tags shall be affixed directly on the blinds after installation and the lead worker signs off the blind list under “Blind Installed”.

d. The equipment owner shall verify the proper placement of all blinds by doing the

following:

Remove the blind tag stubs from the installed blinds

Complete the information on the blind tag stubs

Initial the blind list under “Blind Installed”

Place the blind list and the blind tag stubs and attach to the outside of the lockbox

v. Using the Blind Tags and Blind List for Deblinding

a. The equipment owner shall verify that the equipment or system is ready for deblinding.

If it is found that hazardous energy and/or hazardous materials are present in the equipment, the requirements for first break shall be followed prior to starting deblinding activities.


Rev. 1


29-Jan-2014

of 26


Once all these preparations are completed, the equipment owner shall sign off the blind list under “OK to Remove Blind”.

b. The lead worker shall verify that the equipment or system is ready for deblinding and signs off the blind list under “OK to Remove Blind”.

c. The lead worker and crew shall proceed with the removal of blinds ensuring that the blind tag stubs match with the blind tag affixed to the blind.

Blinds without a blind tag stub shall not be removed.

d. Upon completion of deblinding, the lead worker shall hand over all blind tag stubs with the matching blind tags to the equipment owner and signs off the blind list under “Blind Removed”.

e. The equipment owner shall physically verify completion of blind removal in the field

and signs off the blind list under “Blind Removed”.

Blind Tags


Rev. 1


29-Jan-2014

of 26


Appendix E

First Break and Alternate Bolting Diagrams

The diagrams below illustrate some bolting configurations for first break and alternate bolting.

i. Bolts marked in black identify the bolts which can be removed for alternate bolting. The numbers represent the recommended sequence for removing the bolts.

ii. Bolts marked in red identify the bolts that need to remain intact prior to first break. First break requirements apply when removing any of these bolts.

Figure 1: Four-Bolt Flange


Rev. 1


29-Jan-2014

of 26


Figure 2: Eight-Bolt Flange

Figure 3: 12-Bolt Flange

1

2 3

4

5

6

7

8

1

4

3

2


Rev. 1


29-Jan-2014

of 26




1

2 3

4

5

6

7

8 9

10

11

12

1

2

3

4

5

6

7

8


Rev. 1


29-Jan-2014

of 26



1

2

3

4 5

6

7

8

9

10

11

12

13

14

15

16

SAFETY Rev. 1 - Q-Chem Internet · JSA – Job Safety Analysis ... Purging, Venting, ... If the...

Documents

Transcript of SAFETY Rev. 1 - Q-Chem Internet · JSA – Job Safety Analysis ... Purging, Venting, ... If the...