API 2003: Protection Against Ignitions Arising Out of Static, Lightning, and Stray Currents

Question 1

What are four conditions that must be present for an electrostatic charge to be a source of ignition? (API 2003-15, Section 4.1.1)

Answer 1

a) a means of generating an electrostatic charge
b) a means of accumulating an electrostatic charge capable of producing an incendiary spark
c) a spark gap
d) an ignitable vapor-air mixture in the spark gap

Question 2

How can brush discharges be eliminated? (API 2003-15, Section 4.1.4.3)

Answer 2

By avoiding the charge build-up on the product through adequate residence times, flow rate restrictions, etc., and by designing and operating equipment to avoid conductive objects protruding into the container.

Question 3

What is a “spark promoter?” (API 2003-15, Section 4.5)

Answer 3

A grounded or ungrounded conductive object that provides the necessary spark gap for a spark to occur.

Question 4

What is “grounding?” (API 2003-15, Section 3.1.8)

Answer 4

The process of bonding one or more conductive objects to the ground, so that all objects are at zero (0) electrical potential (also referred to as “earthing”).

Question 5

What is “bonding?” (API 2003-15, Section 3.1.2)

Answer 5

The practice of providing electrical connections between isolated conductive parts of a system to preclude voltage differences between the parts.

Question 6

What is “dissipation”? (API 2003-15, Section 4.1.3)

Answer 6

Electrostatic charges continually leak away from a charged body. Dissipation of the charge starts as soon as a charge is generated and can continue after charge generation has stopped.

Question 7

Owners shall ensure that tank trucks and tank cars have a properly operating __________ system. (API 2003-15, Section 4.2.13(e))

Answer 7

Grounding

Question 8

What two items should bonding shunts on open floating-roof tanks connect? What is the primary purpose of these bonding shunts? (API 2003-15, Section 4.5.8.1)

Answer 8

a) Internal floating-roof tanks require some form of bonding; either by the use of shunts or a metal cable between the floating roof or cover and the tank roof or shell.
b) This will sufficiently remove any electrostatic charges on the floating roof or cover.

Question 9

What are the two usual forms of bonding used on internal floating-roof tanks? (API 2003-15, Section 4.5.8.1)

Answer 9

Shunts or a metal cable

Question 10

Charge generation greatly increases if a _________ is placed in a piping system. (API 2003-15, Section 4.6.3.1)

Answer 10

Filter (10 to 200 times more charge is produced when filter box is present)

Question 11

Do metallic tanks that do not rest directly on the ground but are connected to grounded piping systems require additional grounding to provide for the safe dissipation of lightning strokes? For what reason may supplemental grounding be required? (API 2003-15, Section 5.4.1)

Answer 11

Metallic equipment that does not rest directly on the ground but is connected to a grounded piping system is usually safe for propagation to ground of lightning strokes. Such equipment may require supplemental grounding to prevent foundation damage.
Metallic tanks, equipment, and structures that are insulated from ground should be adequately grounded and bonded. Such connections, when properly designed, provide a means of propagating the discharge to ground without causing damage to insulating materials that may be in the direct path of the stroke.
Structures made of insulating materials such as wood, plastic, brick, tile, or nonreinforced concrete are typically not inherently grounded for lightning protection. They can be protected from direct-stroke lightning by means of properly designed lightning protection systems