// CODE SNIPPET
66.21.7.1* Prevention of Overfilling of Storage Tanks
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Facilities with aboveground tanks larger than 1320 gal (5000 L) storing Class I or Class II liquids shall establish procedures or shall provide equipment, or both, to prevent overfilling of tanks. [30:21.7.1]
Facilities with aboveground tanks that receive and transfer Class I liquids from mainline pipelines or marine vessels shall establish and follow formal written procedures to prevent overfilling of tanks utilizing one of the following methods of protection:
- Tanks shall be gauged at intervals in accordance with established procedures by personnel continuously on the premises during product receipt. Acknowledged communication shall be maintained with the supplier so flow can be shut down or diverted in accordance with established procedures.
- Tanks shall be equipped with a high-level detection device that is either independent of any gauging equipment or incorporates a gauging and alarm system that provides electronic self-checking to indicate when the gauging and alarm system has failed. Alarms shall be located where personnel who are on duty throughout product transfer can arrange for flow stoppage or diversion in accordance with established procedures.
- Tanks shall be equipped with an independent high-level detection system that will automatically shut down or divert flow in accordance with established procedures.
[30:21.7.1.1]
Alternatives to instrumentation described in 66.21.7.1.1(2) and 66.21.7.1.1(3) shall be allowed where approved as affording equivalent protection. [30:21.7.1.2]
Instrumentation systems covered in 66.21.7.1.1(2) and 66.21.7.1.1(3) shall be wired fail-safe, such that valid alarm conditions or system failures create an alarm condition that will notify personnel or automatically shut down or divert flow. [30:21.7.1.3]
Written instrumentation performance procedures shall be established to define valid alarm conditions and system failures in accordance with API 2350, Overfill Protection for Storage Tanks in Petroleum Facilities. [30:21.7.1.3.1]
System failure shall include but not be limited to the following:
- Loss of main electrical power
- Electrical break, short circuit, or ground fault in the level detection system circuit or the alarm and signal circuit
- Failure or malfunction of the level detection system control equipment or signaling devices
[30:21.7.1.3.2]
Formal written procedures required by 66.21.7.1.1 shall include the following:
- Instructions covering methods to check for lineup and receipt of initial delivery to tank designated to receive shipment.
- Provision for training and monitoring the performance of operating personnel by supervisors.
- Schedules and procedures for inspection and testing of gauging equipment and high-level instrumentation and related systems. Inspection and testing intervals shall be approved but shall not exceed 1 year.
[30:21.7.1.4]
An underground tank shall be equipped with overfill prevention equipment that will operate as follows either alert the transfer operator when the tank is no more than 90 percent full by triggering an audible and visual high-level alarm or automatically shut off the flow of liquid into the tank when the tank is no more than 95 percent full. [30:21.7.1.5]
Shop-fabricated aboveground atmospheric storage tanks, constructed to the recognized standards of 66.21.4.2.1.1, shall meet the requirements of 66.21.7.1.6.1 through 66.21.7.1.6.4 whenever the vertical length from the tank bottom to the top of the fill, normal vent, or emergency vent exceeds 12 ft (3.7 m). [30:21.7.1.6]
In no case shall these provisions restrict or interfere with the functioning of the normal vent or emergency vent. [30:21.7.1.6.3]
Related Code Sections
66.21.7.1* Flammable and Combustible Liquids, Prevention of Overfilling of Storage Tanks
equipment, or both, to prevent overfilling of tanks. [ 30: 21.7.1 ...
Fire Code 2018 of West Virginia > 66 Flammable and Combustible Liquids > 66.21 Storage of Liquids in Tanks — Requirements for All Storage Tanks > 66.21.7 Operation of Storage Tanks > 66.21.7.1* Prevention of Overfilling of Storage Tanks
66.21.7.1.2 Flammable and Combustible Liquids,
Alternatives to instrumentation described in 66.21.7.1.1(2) and 66.21.7.1.1(3) shall be allowed where approved as affording equivalent protection ...
Fire Code 2018 of West Virginia > 66 Flammable and Combustible Liquids > 66.21 Storage of Liquids in Tanks — Requirements for All Storage Tanks > 66.21.7 Operation of Storage Tanks > 66.21.7.1* Prevention of Overfilling of Storage Tanks > 66.21.7.1.2
66.21.7.1.3.2 Flammable and Combustible Liquids,
System failure shall include but not be limited to the following: Loss of main electrical power Electrical break, short circuit, or ground fault ...
Fire Code 2018 of West Virginia > 66 Flammable and Combustible Liquids > 66.21 Storage of Liquids in Tanks — Requirements for All Storage Tanks > 66.21.7 Operation of Storage Tanks > 66.21.7.1* Prevention of Overfilling of Storage Tanks > 66.21.7.1.3 > 66.21.7.1.3.2
66.21.7.1.4 Flammable and Combustible Liquids,
of initial delivery to tank designated to receive shipment. Provision for training and monitoring the performance of operating personnel by supervisors ...
Fire Code 2018 of West Virginia > 66 Flammable and Combustible Liquids > 66.21 Storage of Liquids in Tanks — Requirements for All Storage Tanks > 66.21.7 Operation of Storage Tanks > 66.21.7.1* Prevention of Overfilling of Storage Tanks > 66.21.7.1.4
66.21.7.1.6 Flammable and Combustible Liquids,
Shop-fabricated aboveground atmospheric storage tanks, constructed to the recognized standards of 66.21.4.2.1.1, shall meet the requirements ...
Fire Code 2018 of West Virginia > 66 Flammable and Combustible Liquids > 66.21 Storage of Liquids in Tanks — Requirements for All Storage Tanks > 66.21.7 Operation of Storage Tanks > 66.21.7.1* Prevention of Overfilling of Storage Tanks > 66.21.7.1.6