API 2207

REVIEW1. An act or operation that can produce a spark or flame hot enough to ignite flammable

vapors is called: Hot work. 1.1

2. Tanks that have contained flammable or combustible liquids, regardless of their age and type of construction, must be considered unsafe until approved by:

Safety inspections. 1.13. Who authorizes the hot work and should designate the necessary safety precautions?

A competently trained or experienced person. 3.1.24. What is an example of adequate first-aid and fire-fighting equipment that should be

available and ready for instant use? Fire-extinguishers and water hose lines. 3.1.3

5. Work permits for the job, tank entry and hot work must be: Properly signed and issued before the work is started. 3.2.3

6. What piece of equipment should be in operation at all times during entry and hot work?

An air mover of large enough capacity to provide fresh air inside the tank. 3.2.2

7. Lines to and from the tank that have been disconnected, blanked off, or otherwise isolated should not be __________ during entry and hot work.

Disturbed. 3.2.28. In order to weld on a tank that has contained leaded gasoline, the area 12” on each

side of the location to be welded must be scraped down to bare metal. As an alternate to scraping down to bare metal:

The welders should use air-supplied respiratory equipment while welding. 3.2.4

9. Where do you attach grounding leads from a welding machine on a tank when hot work is to be performed?

Attach the leads directly to a bared surface on the tank shell. 3.2.510. While hot work is in progress, all work areas must be monitored for _________ and

combustible and toxic atmospheres. Oxygen deficiency. 3.2.7

11. Appropriately sized openings are sometimes made in the tank bottom by cold cutting or by drilling holes in each area where hot work is to be performed. What purpose do these openings have?

These openings facilitate VT and help free gas from beneath the tank btm. 4.212. In order to make small repairs, usually involving welding of corrosion pits and

patches or other localized jobs, the following procedure is used: Tap a ½” (13mm) hole adjacent to the repair area. Connect a supply of inert gas to the tap using metal tubing. Use a control valve with a flow indicator to prevent over pressuring of the tank bottom. Establish a flow of inert gas under the tank bottom in the vicinity of the welding to sweep away the flammable vapors (or dilute them sufficiently). Monitor the area to assure that the oxygen content remains between 19.5 and 22.5%. When welding is complete, plug the hole with a tapered pin or other device and promptly back weld the pin. An example of inert gas is:

Carbon dioxide. 5.2

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API 2207

REVIEW13. When repairs involving hot work include most of the tank bottom, it may be desirable

to displace the flammable liquids/vapors beneath the tank by: Water flooding. 5.3

14. Repairs around the perimeter of a tank may be made safely by excavating under the edge of the tank a minimum of __________ beyond the point of any hot work area. Monitor area continuously to assure the oxygen content and seal off all openings between the floor plates and the tank foundation by packing them with mud. Use a vapor indicator to check the excavations and the seals. Continuously monitor the excavations and the surrounding area for airborne chemicals or gas. Ventilate the excavation if necessary.

30 centimeters (12”). 5.415. What is the depth of sand recommended by API publication 2207 to be placed over

an existing tank floor when a double bottom is to be installed? 10 centimeters (4”). 5.5

16. When using a hand or air operated tool to cold cut a tank bottom, what should be applied continuously to the cutting edge of the tool and why should it be applied?

A coolant should be applied to reduce the heat of friction. 5.6

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