API TES – TANK ENTRY SUPERVISOR

PROJECT PLANNING – PART I

TANK CLEANING CHECKLISTGeneral

API 2016 p.56, Sec. 10Tank Cleaning Checklist This section assists employers in developing their own company- or facility-

specific tank cleaning checklist that may be used to develop plans for safe tank cleaning operations. The checklist includes: Applicable government regulations. Employer policies, procedures and programs. Tank design, condition, location and products stored. Environmental concerns and requirements. Internal and external operations impacting on the tank cleaning. Rescue requirements. Reason for cleaning the tank.

Project Planning 2

TANK CLEANING CHECKLISTPre-Planning

Employers should develop a preplan for the tank cleaning operation.

Project Planning 3

TANK CLEANING CHECKLISTEngineering & Operations Planning

Employers should establish the reasons for tank cleaning. Determine the duration of the job and establish starting and completion dates

for each phase of the tank cleaning operation. Review applicable engineering drawings, including: Tank site plot plans Tank and piping details Tank fire protection systems Electrical utilities

Project Planning 4

TANK CLEANING CHECKLISTEngineering & Operations Planning Cont’d

Determine isolation and LOTO requirements, identify all items to be isolated on the plans and drawings and develop an isolation plan and blinding list for the tank to cleaned. Physically inspect the tank to verify that items not on the plans and drawings

are included in the isolation plan and blind list. Determine area or zone electrical classification requirements and safe locations

for site tank cleaning equipment, construction, utility trailers, and vacuum trucks. Determine if degassing vapors is required and establish responsibility for

obtaining necessary regulatory permits, such as environmental permits.

Project Planning 5

TANK CLEANING CHECKLISTHazard Analysis & Protection Requirements

Employers should review MSDSs or equivalent information covering sludge/residue and chemicals: Establish safe limits for flammable vapors and toxic gases. Establish requirements for selection, calibration, adjustment, bump testing,

use and maintenance of oxygen, combustible vapors, and toxic gas measuring instruments. Determine respiratory protection and PPE requirements.

Project Planning 6

TANK CLEANING CHECKLISTHazard Analysis & Protection Requirements Cont’d

Determine and assess product, sludge, and residue potential safety and health hazards. Identify potential tank specific physical hazards, such as, leaking tank bottom

or column, corroded or faulty tank roof, broken ladder or stairway, non-operable legs or floating roofs, double bottom or walls, interior piping, mixers, heating coils or appurtenance. Provide for eating, washing, toilet, shower and change room facilities.

Project Planning 7

TANK CLEANING CHECKLISTConfined Space Program

Employers should review the facility confined space program as related to the tank to be cleaned and the proposed work: Establish requirements to classify and reclassify the tank as a permit required

or non-permit required confined space and as a non-confined space. Determine the conditions under which entry upon the floating roof of the

tank to be cleaned will be permit required confined space entry, non-permit required confined space entry or non-confined space entry.

Project Planning 8

TANK CLEANING CHECKLISTSite Survey

Employers should conduct a tank pre-cleaning site survey to assesses Determine the tank’s location in relation to other tanks, piping, process units,

and utilities both within and outside of the facility. Review the scope of work and its impact on the area, including potential flow

of vapors or product in event of a release or spill. Determine potential area hazards and their impact on the tank cleaning

operation.

Project Planning 9

TANK CLEANING CHECKLISTSite Survey Cont’d

Review isolation & blinding list and LOTO list against actual equipment configurations to assure all connections and sources of energy are covered. Review available fire protection, accessibility for rescue, the impact of a tank

cleaning emergency on the facility, and the impact of an outside emergency on the tank cleaning (alarms, emergency notification and evacuation procedures, egress routes, and assembly area). Review site congestion, equipment and trailer location, access roads, and

vehicular traffic concerns.

Project Planning 10

TANK CLEANING CHECKLISTEmployer Responsibilities (Owner/Operator and Contractor)

Employers should qualify and select contractors and subcontractors and establish tank cleaning procedures Determine the specific work to be performed by facility employees and by

contractors. Include the facility tank administrative procedures, operating controls, permit

policy, LOTO procedures, safe work practices, environmental requirements, and emergency planning and response procedures as part of the contract. Establish whether the facility, contractor, or subcontractors will be

responsible for the control and safety of tank cleaning workers or specify the employer’s and each contractor’s authority and responsibilities if assignments are to be shared. Establish the means of communication at the job site between contractor and

facility supervisors and employees. Project Planning 11

TANK CLEANING CHECKLISTPermit Requirements

Employers should review the facility safe work, hot work and entry permit system program. Determine the types of permits needed, permit retention, requirements for

permit authorization, permit issuance and cancellation, information required on permits, and the signatures and acknowledgements required on permits. Identify and qualify entry supervisors who will issue the permits, and persons

who will conduct testing during the tank cleaning operation. Establish requirements for issuing work and entry permits for

owner/operator employees, owner/operator contractor (other than tank cleaning contractor) employees and tank cleaning contractor and subcontractor employees working both inside and around the tank to be cleaned.

Project Planning 12

TANK CLEANING CHECKLISTProduct Removal

Employers should establish procedures for removal of recoverable and non-recoverable product, sludge and residue from the tank through existing connections prior to the start of tank cleaning operations and opening manholes. Determine disposition of recoverable and non-recoverable product. Decide how sludge and residue will be classified and its on or off-site storage,

treatment or disposal. Check to determine if the facility NPDES will allow tank bottom water and

wash water to go into the API separator and if so, assure that contaminated water will not surpass separator requirements.

Project Planning 13

TANK CLEANING CHECKLISTEquipment & Material Needs

Employers should determine required tank cleaning equipment and materials appropriate for the work to be done and for anticipated hazards and exposures Pumping and vacuum equipment appropriate for the anticipated pressures

and exposures, to remove product, sludge and residue and containers to collect and store sludge and residue prior to treatment or disposal. Vapor and gas freeing, degassing, purging, inerting and ventilation Predetermine required number, size and capacity and location of air blowers

and eductors based on tank size and configuration, back pressure and diameter and length of exhaust duct or recovery line.

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TANK CLEANING CHECKLISTEquipment & Material Needs Cont’d

Chemicals, solvents, water or steam required for sludge removal, vapor and gas freeing and cleaning. Artificial lighting, electrical GFI and bonding equipment. Compressed breathing air cylinders or compressors and air compressors for

operating air-powered tools and equipment. Temporary supports. Emergency communication, response and rescue equipment. Cleaning materials.

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TANK CLEANING CHECKLISTEmergency Plans

Employers should review the facility and contractor’s emergency plans and applicable regulatory emergency response requirements. Establish an emergency response plan specific to the tank being cleaned that

covers emergencies inside and around the tank being cleaned and elsewhere in the facility impacting on the tank cleaning operations (medical and first aid, fires, spills and releases and rescue operations). Determine and designate either a qualified outside rescue service or identify

employer designated rescuers.

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TANK CLEANING CHECKLISTTank Pre-Cleaning Meeting

Employers should conduct a tank pre-cleaning meeting including facility, contractor and subcontractor personnel to review the above information and assign specific responsibilities for each phase of the tank cleaning operation.

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TANK CLEANING CHECKLISTRemoving Recoverable Product

Employers should develop a plan for removing all recoverable product from the tank.

Project Planning 18

TANK CLEANING CHECKLISTArea Protection

Employers should limit access to the area around the tank to personnel authorized on the safe work permits and entry permits.

Set up notices and barricade the area around the tank to be cleaned to prevent unauthorized access.

Employers should be responsible for authorized and unauthorized access by their own employees.

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TANK CLEANING CHECKLISTEntry Onto Floating Roofs

Employers should determine the requirements for entry upon floating roofs in accordance with the facility’s confined space program and classification of floating roof as permit required confined space, non-permit required confined space or non-confined space. Determine industry and facility requirements for entry onto floating roofs of

tanks in service.

Project Planning 20

TANK CLEANING CHECKLISTEntry Onto Floating Roofs

Plan descent upon a floating roof when it is a high level (preferably within 5 ft. of the top of the tank). Verify that the floating roof is safe to walk on or provide appropriate flooring

before entering on top of a floating roof. Conduct required testing to assure that the atmospheric conditions on top of

the roof are with acceptable limits before entry onto a floating roof.

Project Planning 21

TANK CLEANING CHECKLISTEntry Onto Floating Roofs Cont’d

Gauge the tank to determine the amount of water, sludge and recoverable product. Check the integrity of the floating roof to prevent damage to the roof as the

tank is emptied. Pull a representative number of the roof legs and check for conditions and

integrity.

Project Planning 22

TANK CLEANING CHECKLISTEntry Onto Floating Roofs Cont’d

Lower the legs of floating roof tanks while the tank is still in service, preferably when the tank is full. Check the roof drain hoses to assure they will not kink or be blocked as the

roof is slowly and carefully lowered on its legs. Check that roof drains are functioning after an open top (external) floating

roof is on its legs to prevent water accumulating on the roof as the extra weight may damage the roof or cause the roof legs to puncture the tank bottom.

Project Planning 23

TANK CLEANING CHECKLISTRemoving Product Through Product Lines

An important safety practice in cleaning tanks is to remove as much recoverable product as possible from the tank before it is opened.

Employers should establish procedures to first remove recoverable product through fixed connections and then through an open manhole or other large tank opening.

Project Planning 24

TANK CLEANING CHECKLISTRemoving Product Through Product Lines Cont’d

Withdraw product through tank suction lines until it is below the outlet level and the main pump nearly loses suction.

Depending on the amount of sludge, residue and water in the tank, determine if the remaining recoverable product can be removed using existing tank connections.

Before and during emptying through fixed connections, obtain samples, for testing and determination as to whether or not recovered product can be returned to stock.

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TANK CLEANING CHECKLISTProduct Removal by Suction Pump

Employers should use a portable air or steam driven suction pump and conductive hose and couplings to complete the process of emptying the tank of all recoverable product through fixed connections.

Internal combustion powered portable pumps shall not be used inside the dike area.

Provided that the employer permits the use of an approved electric driven portable pump, inspect the explosion proof motor and all electrical connections to assure that they meet area electrical classification requirements before use.

Check the integrity of the pump, hose and couplings and inspect the safety features of the system.

Project Planning 26

TANK CLEANING CHECKLISTProduct Removal by Suction Pump Cont’d

Conduct atmospheric testing to assure that flammable vapor-in-air levels are within acceptable limits and issue a permit to move and position the portable pump and hoses into place in the dike area

Directly connect and bond the portable pump suction hose to an appropriate tank connection.

Assure that the portable pump is grounded and electrically bonded to both the product tank and the receiving container or tank (bond the end of the discharge hose to the receiving tank or container).

Pump out the remaining liquid from the tank with the portable pump until it loses suction.

Collect the liquid in an approved container or tank for disposal or return to stock..

Project Planning 27

TANK CLEANING CHECKLISTProduct Removal by Flotation

Once product has dropped below the level of the fixed tank connections, employers may remove remaining recoverable product by pumping water or fuel oil into the tank and floating the product out through a fixed connection.

Fuel oil may be used to remove gasoline and other low flash products from tanks through closed connections, however, the potential still exists for flammable vapors when the tank is opened.

The remaining recoverable product will float on the water or fuel oil and can be removed through the fixed tank discharge line, water draw, or stripper valves.

Water or fuel oil must be injected slowly to prevent electrostatic charge buildup from splash filling.

Project Planning 28

TANK CLEANING CHECKLISTProduct Removal by Vacuum Pump

If the remaining liquid is to be removed from the tank by vacuum equipment, employers shall apply the same safety precautions required for portable pumps to vacuum operations.

The vacuum truck shall be placed up wind, no closer than 50 ft. (15 m) from the tank and preferably outside of or on top of the tank dike.

The vacuum process creates static electricity. Conductive hoses and couplings shall be used, the vacuum truck grounded and the vacuum truck and all hoses and couplings shall be electrically bonded to the product tank and the receiving tank or vessel.

Vapors discharged from the vacuum truck can be in the explosive range and must be discharged at a high level (at least 12 ft.) above the ground or degassed.

Project Planning 29

TANK CLEANING CHECKLISTRemoving Recoverable Product Through Open Manholes

If a tank manhole has to be opened to remove recoverable low flash or hazardous product from the tank, employers should assure that entry supervisors issue an entry permit for this activity.

Install and electrically bond an eductor to a manhole at the top of the tank. Start it at low capacity to create a slight negative pressure in the tank to prevent vapors from escaping at ground level when the bottom manhole is opened.

If the tank has a floating roof, install the eductor at the top of the tank and arrange flexible ducting to draw air through a manhole from beneath the floating roof.

Project Planning 30

TANK CLEANING CHECKLISTRemoving Recoverable Product Through Open Manholes Cont’d

Electrically bond one bottom manhole cover to the tank and then remove it. Immediately cover the open manhole with a fire blanket or similar barrier to minimize vapor emissions to the atmosphere.

As soon as the bottom manhole is opened, increase the airflow to prevent escape of vapors through the bottom manhole.

Install a pan just inside the manhole, above the level of the sludge to collect recoverable product. Bond the suction line to the pan, the product tank and the pump or vacuum truck. Install a check valve in the suction line to prevent back flow.

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TANK CLEANING CHECKLISTRemoving Recoverable Product Through Open Manholes Cont’d

Before and during emptying from the open manhole, obtain samples of recoverable product for testing and determination as to whether or not recovered product can be returned to stock.

Replace the shell manhole cover when product is completely recovered and stop the eductor in order that the tank does not collapse.

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TANK CLEANING CHECKLISTTank Isolation

Employers shall develop a tank isolation plan that identifies all items to be isolated, LOTO, required permits and a list of isolation devices, blinds, locks and tags and identifies those responsible for the isolation operations.

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TANK CLEANING CHECKLISTIsolation Requirements

Employers should prepare a list of items to be isolated, LOTO (inlet and withdrawal lines, water draw, sample and gauging lines and devices, vapor recovery lines, pumps, valves, vents and relief devices, electronic, hydraulic and mechanical switches and power sources, heating coils and mixers and appurtenances and connections).

Assign responsibility for isolation and LOTO in accordance with facility procedures and tank pre-cleaning agreements between owners/operators and contractors.

Project Planning 34

TANK CLEANING CHECKLISTIsolation Requirements Cont’d

Assure that all recoverable product has been removed from the tank before isolation.

Establish safe work procedures for conducting isolation and LOTO.

Determine and assure workers use appropriate personal protective clothing and respiratory protective equipment during opening and blinding of lines and LOTO of energy sources.

Project Planning 35

TANK CLEANING CHECKLISTTank Suction & Discharge Lines

Employer shall assure that all suction and discharge lines are closed at the tank and LOTO devices are installed on the valves.

Control ignition sources in the area, before opening any lines.

Secure, LOTO all dike valves leading from the area around the tank to be cleaned and cover sewer openings or drains in the dike area that cannot be closed by valves to prevent vapors from entering into the dike area or spills to leave the dike area.

Check to be certain lines have been depressurized and drained and that in-line drain valves are open and clear of obstructions.

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TANK CLEANING CHECKLISTTank Suction & Discharge Lines Cont’d

Carefully, drain, separate and isolate lines by blinding as close to the tank as possible or by double block and bleed as close to the tank as possible. Alternatively, valves may be dropped and lines blanked in order to achieve isolation.

Review thermal relief requirements (such as breaking, capping or rerouting) for piping being isolated and institute measures to guard against over pressuring piping and related equipment.

Install blinds on the side of a blocked valve that is most consistent with pressure testing requirements.

Project Planning 37

TANK CLEANING CHECKLISTOther Tank Lines, Appurtenances, and Connections

Employers shall assure that all other lines and connections at the tank are drained, closed and isolated by blinding or installing LOTO devices on the valves.

Other lines, shall be thoroughly purged, cleaned flushed and/or isolated prior to the tank being considered isolated.

If the tank has a fixed or semi-fixed fire foam system, inspect the piping to assure that no liquid or vapors are contained therein, but do not disconnect or isolate the system.

If necessary, drain and flush the foam line, but do not disconnect the foam system.

Check and replace the foam line chamber glass seal if missing, cracked or broken.

Project Planning 38

TANK CLEANING CHECKLISTEnergy Sources

Employers shall verify that isolation, LOTO has been performed according to the isolation and blinding list and that no items were overlooked.

Isolate all electrical energy sources and instrumentation devices by disconnecting and installing LOTO devices on the switches.

Isolate all mechanical and thermal energy sources by disconnecting and installing LOTO devices on the switches.

Project Planning 39

TANK CLEANING CHECKLISTCathodic Protection

Employers shall assure that if a tank has cathodic protection safe isolation practices are followed, in order, whenever a tank valve or line is to be disconnected.

Turn off the cathodic protection system.

Install a bond wire from the tank to the lines.

Disconnect and remove the valve or line.

Remove the bond wire only after the valve of line is disconnected.

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TANK CLEANING CHECKLISTVerification

Employers shall establish and implement procedures to verify that isolation has been accomplished.

Lines are disconnected, blinded and/or double blocked and bled.

Energy sources are disconnected and LOTO and de-energized.

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TANK CLEANING CHECKLISTVapor Freeing The Tank

Occurs after all recoverable product has been removed from a tank and the tank has been isolated.

Employers shall develop and entry supervisors shall implementing procedures for safely vapor and gas freeing and degassing the tank before tank cleaning commences.

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TANK CLEANING CHECKLISTVapor & Gas Freeing (Degassing) Methods

Employers shall select an appropriate method of vapor and gas freeing, degassing and ventilating tanks in accordance with the tank design, size, configuration, usage, physical condition, environmental regulations and facility requirements and conditions.

Mechanical vapor and gas freeing and ventilation requirements depend on the tank design, size and characteristics (discussed elsewhere in this RP).

In order to minimize air pollution, provide degassing, where required by the facility or jurisdiction, by incineration, condensation and recovery or treatment of vapors prior to emissions to the atmosphere.

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TANK CLEANING CHECKLISTVapor & Gas Freeing (Degassing) Methods Cont’d

Ventilation, which occurs after vapor and gas freeing, provides an appropriate number of air changes (normally 5/hour) specified in regulations or facility requirements in order to maintain the atmosphere within the tank at acceptable permit limits during tank cleaning operations.

Obtain necessary permits for vapor and gas freeing direct to the atmosphere and degassing.

Project Planning 44

TANK CLEANING CHECKLISTControl of Ignition Sources

Employers shall assure that entry supervisors and workers are aware that vapor and gas freeing and degassing is a potentially hazardous phase of tank cleaning.

Entry supervisors shall also be aware that the use of air or steam driven mechanical blowers and eductors to dilute and remove vapors is preferred as an electric motor could be a source of ignition.

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TANK CLEANING CHECKLISTControl of Ignition Sources Cont’d

Assure that all air moving equipment is electrically bonded to the tank.

Control ignition sources around the tank and in the dike area during vapor and gas freeing.

Conduct continuous or periodic atmospheric testing and degassing equipment testing to monitor conditions, maintaining records of degassing emissions.

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TANK CLEANING CHECKLISTControl of Ignition Sources Cont’d

Do not conduct vapor and gas freeing during thunder and lighting storms.

Some degassing systems have the potential to create heat and become a source of ignition, with a potential for flashback into the tank.

Provide degassing units with appropriate flame arrestors and follow safe operating practices.

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TANK CLEANING CHECKLISTControl of Ignition Sources Cont’d

If an air compressor is used, place it in a safe location, preferably outside the dike area, up wind and 50 ft. from the tank.

Establish requirements for use of only approved electrically powered equipment.

Assure all equipment permitted to be used meets NFPA 70, Class I, Div 1, Group D, or Zone 1 (or greater) requirements, is explosion proof, is inspected by a qualified person for integrity and is approved for use by the employer.

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TANK CLEANING CHECKLISTControl of Ignition Sources Cont’d

Ignitable pyrophoric iron sulfides may be present in tanks containing sour products. If so, provide continuous water spray keep tank surfaces wet during vapor and gas freeing, degassing and ventilation.

Shut down all hot work and other sources of ignition within the dike area before opening the tank manholes to connect eductors or blowers and flexible intake and exhaust dust.

Supervisors should restrict personnel from working within the dike area around the outside of the tank during vapor and gas freeing operations until the level of flammable vapors leaving the tank is 50% LEL or lower and the atmosphere in the dike area is within acceptable limits.

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ASSESSMENT

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