Date Issued: October 2011 Revision Date: August 2012 Review Date: August 2015 Revision #

Transcription

1 SUNCOR ENERGY PRODUCTS DISTRIBUTION TERMINAL OPERATING MANUAL STANDARD OPERATING PROCEDURE SAFEWORK PRACTICES CAT A-2 SOP #28 Date Issued: October 2011 Revision Date: August 2012 Review Date: August 2015 Revision # PURPOSE This procedure provides Terminal Operator instructions and precautions to properly place internal floating roof tanks into service. With an internal floating roof sitting on its legs and product begins to fill the tank, an explosive vapour space is created in gasoline, diesel and ethanol tanks. Excessive fill rate could generate sufficient static discharge to ignite the explosive mixture. In addition to the risk of explosion, excessive fill rates have the potential for lifting the internal floating roof unevenly and causing the roof to tilt and sink. Normal practice is to gravity feed the tank from an adjacent tank or to fill the tank at a reduced velocity until the roof begins to float at which time the fill rate can be increased to the maximum design velocity of the diffuser. Since the vapors from below the IFR, they will be forced above the IFR. During the initial fill it is recommended that the tank be filled to the maximum safe fill level at this time so that the displaced vapors can escape through the roof vents. Appropriate fill rates for all terminal tankage MUST be outlined to all involved personnel prior to undertaking the task. Flow rates on various sizes of pipe are limited to 3 feet per second velocity through the inlet nozzle until the fill nozzle is submerged and the IFR is afloat. Technical Concerns Floating an Internal Roof Page 1 of 8

2 2.0 SCOPE This Standard Operating Procedure shall apply to all employees and contractors at Suncor Energy Distribution Terminals who may be required to float an internal roof. The scope of this document is to define and communicate the precautions and requirements that involve floating an internal tank roof to Suncor Personnel and applicable Contractors working within Distribution 3.0 REFERENCED DOCUMENTS API RP PRECAUTIONARY STATEMENTS 4.1 Training All Suncor Personnel and Contractors whom in the execution of their normal job function may be required to float an internal tank roof must review and comply in full with this document 4.2 Specific Hazards Typical hazards that may be encountered while working with hoses may include; Identified Hazards o Hazards Identified on the Work Permit Work Environment Hazards o Limited Access / Egress o Exposure to Hydrocarbons Floating an Internal Roof Page 2 of 8

3 Personal Limitations o Distractions in work area o Confusing instructions o First Time Performing the Task 4.3 Personal Protective Equipment Personal protective equipment as outlined in Distribution Standard Operating Procedure, Cat A-1, SOP #10 or as specified on the Safe Work Permit, dependent upon work to be completed as per job scope requirements. 5.0 ROLES & RESPONSIBILITIES Terminal Management; Accountable to ensure full implementation and compliance of this standard operating procedure. Operating Authority / Performing Authority / Transport Drivers; Responsible to ensure full compliance with this procedure. 6.0 SUSTAINMENT AND CONTINUAL IMPROVEMENT Rimouski Terminal Management; Responsible to initiate document review process. Review process to comply with Distribution Standard Operating Procedure Cat A3, SOP #01. To ensure this Standard Operating Procedure document meets all applicable Suncor OEMS and PSM standards, this document is to be reviewed at a frequency not exceeding 3 years, or when conditions change sufficient to warrant a review. Floating an Internal Roof Page 3 of 8

4 7.0 PREREQUISITES Working knowledge of tankage and gauging system Refer to MSDS for information regarding health and environmental concerns for the product Recommended inflow rate to be at 3 ft./sec as per API RP 2003, Section 4.5. (see flow chart and flow calculation example) 2. Excess inflow rates during the refloating of a tank can damage the roof by creating violent surface turbulence. 3. Excess inflow rate can produce abnormally high vapour emission and static charge build-up. 4. Excess inflow rates could create flammable fuel-air mixture both above and below the floating roof. 5. In cold weather, any water residue (i) on the tank bottom could freeze around roof legs, and (ii) on roof seals, may become frozen to the tank shell. This may impede the lifting of the roof and could damage the seal of the floating roof. Floating an Internal Roof Page 4 of 8

5 9.0 TANK - REFILLING PROCEDURE Pre-Refilling: Review and sign off if applicable, PSSR, FRR, MOC or any Work sheet (if applicable). Check electrical bonding between the tank shell and the internal floating roof (if possible). In coordination with contractor personnel, ensure all blinds have been removed, flanges and drains re-connected and all manways installed and secured. Ensure fill valves on tank are open in preparation to receive product. If the refilling of the tank takes place in freezing temperature, visually inspect the tank and remove any water residue near roof legs also between the floating roof seal and the tank shell. Coordinate restricted fill rate if filling via pipeline or marine vessel. Preference is to gravity feed from adjacent tank. Check to ensure tank vents are clear of debris and operable. 9.1 Prior To Re-floating the Roof When re-filling a tank and or re-floating an internal roof, preference is given to the operation via tank gravitation. If required to fill using pump pressure ( ie pipeline, marine ) constant monitoring is required. Manually open the inlet gate valve at tank nozzle. The inlet velocity of the pumping rate is to be 3 ft. /sec. And the liquid level rising rate at the tank is 630 mm/ hour (i.e. 2-1 / hr.). See flow calculation. Begin filling slowly, use gauging system to verify rate. Floating an Internal Roof Page 5 of 8

6 Liquid level shall be checked periodically to make sure that maximum permissible rate not to exceed 3 ft/sec. This can be done by monitoring tank radar gauge to ensure that the tank liquid level rises not to exceed 105 mm/10 minutes. Communicate with the pump operator (by radio) to adjust the pumping rate if needed. Once tank is filled above manways, hold filling procedure and verify manway / nozzle integrity When product level rises to about 1525 mm (5-0 ) from the tank floor (At a point 305mm (12 ) below underside of the roof deck), visual inspection of the roof shall be made at 60 minute intervals, continuing until completion of the refloating operation. Terminal Management directly responsible for the refloating operation shall frequently inspect the floating roof from the cone roof man way (or inspection hatches), and be prepared at all times to stop product flow if any of the following situations occur: (i) (ii) (iii) (iv) It appears the roof is not floating level. The roof shows signs of binding or hanging up on the tank structure (including sign of binding of the IFR mechanical shoe seal). Product is observed on the top surface of the roof. Uneven relaxation of suspension cable(s) (For Suspended Tank Roof only). 9.2 After Re-floating the Roof After the product level rises to 2440 mm (8 ft.) level, checking and finding no visible problems, Terminal Management shall notify the pump operator to resume normal pumping rate. Floating an Internal Roof Page 6 of 8

7 9.3 Other precautions during tank refilling Periodically check tank nozzles and man ways (for leaking) until the tank reached the desired level. Monitor surrounding area and check LEL from time to time. This is a safety measure to ensure that gasoline vapour expelled from the tank will not be trapped in the tank farm. No source of ignition shall be permitted near the tank during refilling. No refilling shall take place when there is a potential chance of lightning. No manual tank gauging is allowed unless approved by the terminal manager. Tank will only be filled to a level allowed by API FILLING RATES Inlet Pipe Size 3ft/sec flow rate GPM 1 m3/hr flow rate m3/hr m3/hr m3/hr m3/hr m3/hr m3/hr m3/hr m3/hr 10.0 PROCEDURAL DEVIATION Deviations from this standard operating procedure must be authorized using the Management of Change procedure. Deviations must be documented and documentation must include the relevant facts supporting the deviation decision. Floating an Internal Roof Page 7 of 8

8 DATE AUTHOR DESCRIPTION REVISION October 2011 C. Schinck New document issue. Initial Issue August 2012 R. Rattray Re-Formatted for PSM Floating an Internal Roof Page 8 of 8