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North Slope Training Cooperative © North Slope Training Cooperative—revised May 2012. All rights reserved. Static Electricity for Non-Electrical Workers.

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Presentation on theme: "North Slope Training Cooperative © North Slope Training Cooperative—revised May 2012. All rights reserved. Static Electricity for Non-Electrical Workers."— Presentation transcript:

1 North Slope Training Cooperative © North Slope Training Cooperative—revised May All rights reserved. Static Electricity for Non-Electrical Workers (Unqualified) NSTC-27

2 2 © North Slope Training Cooperative—revised May All rights reserved. Course Overview 2

3 3 © North Slope Training Cooperative—revised May All rights reserved. Administration and Safety Emergency Procedures Restrooms/Breaks/Smoking Safety Minute 3

4 4 © North Slope Training Cooperative—revised May All rights reserved. Introductions Name Company and/or position What are some of your common experiences of static electricity? What potential hazards from static electricity are there in your work area or facility? 4

5 5 © North Slope Training Cooperative—revised May All rights reserved. Goal To create a safe environment for employees working in areas where the possibility of static electricity generation exists. 5

6 6 © North Slope Training Cooperative—revised May All rights reserved. Objectives Explain how static electricity is generated and its hazards. Describe the control measures that prevent or reduce the generation of static electricity. Apply those control measures to specific work situations where there is a potential danger from static electricity. 6

7 7 © North Slope Training Cooperative—revised May All rights reserved. Static Electricity and Its Hazards 7

8 8 © North Slope Training Cooperative—revised May All rights reserved. Chemical Safety Board Case Study The tank had a loose linkage on a liquid level gauging system float that separated and created a spark that ignited the naphtha vapors. Heat from the fire ruptured other tanks and destroyed the tank farm. 8 In July 2007 an explosion and fire occurred at Barton Solvents in Wichita, Kansas where a 15,000 gallon, vertical storage tank was being filled with naphtha. Because of its low electrical conductivity, naphtha can produce ignitable vapor-air mixtures inside tanks.

9 9 © North Slope Training Cooperative—revised May All rights reserved. Chemical Safety Board Case Study Three months later at another Barton Solvents facility in Des Moines, Iowa, an explosion occurred while a 300 gallon steel tank was being filled with ethyl acetate, a flammable solvent. The Iowa discharge came from steel parts of the fill nozzle and hose assembly that were not bonded and grounded. 9

10 10 © North Slope Training Cooperative—revised May All rights reserved. What Is Static Electricity? Static electricity is an electrical charge imbalance either positive or negative between two objects. The charge is created by contact and separation (friction) of dissimilar insulating surfaces. Electrons move to the surface of the material with the greatest ability to hold them. 10 BP ASH, pages

11 11 © North Slope Training Cooperative—revised May All rights reserved. How Is Static Electricity Generated? Static electricity is generated by the contact of dissimilar materials. It can occur at solid to solid, solid to liquid, or liquid to liquid interfaces. 11 When there is a great enough charge imbalance, the electrons will flow as a spark or static discharge. This often occurs when touching a metal object after walking across a carpeted floor.

12 12 © North Slope Training Cooperative—revised May All rights reserved. How Is Static Electricity Generated? Movement enhances the transfer of electrons from one material to the other. Some materials lose electrons (positive charge) and some gain electrons (negative charge). Static electricity can be generated when material is moved from one place to another through pipes, by filtering, or by pouring. Other factors influencing the accumulation of static electricity include low humidity, and the low conductivity of a flammable liquid. 12

13 13 © North Slope Training Cooperative—revised May All rights reserved. Static Electric Discharge Static electric discharge is a release of static electricity in the form of a spark that might be capable of causing ignition. The discharge usually occurs in the gap between the two charged bodies, e.g. liquid to liquid, metal to liquid, metal to metal, human body to metal, etc. The energy of a spark discharge is highly concentrated in space and time. Sparks from ungrounded charged conductors, including the human body, are responsible for most fires and explosions ignited by static electricity. 13 NFPA and

14 14 © North Slope Training Cooperative—revised May All rights reserved. Static Electricity Generation in the Oil/Gas Industry In the oil/gas industry, a static charge can result from contact and separation of inflowing liquids through a pipe. Examples would include: oil/gas flowing through a pipeline into a tanker, fuel flowing from a gasoline pump through a hose and nozzle into a vehicle. flammable liquid flowing through a hose into a storage tank. 14

15 15 © North Slope Training Cooperative—revised May All rights reserved. Static Electricity Generation in Oil/Gas Industry 15 Static Producing SituationsExamples Liquid flow through pipes and filtersFueling vehicles, filling a tank Settling of solid particles in liquid Rust and sludge particles settling in a tank Gas bubbling through liquid Air in a liquid rises to the surface or gas bubbles during a filling operation Splashing by the break-up of jets or bubbles Splash filling of tanks, high speed ejection of liquids from nozzles Air movementUsing fans to ventilate a tank

16 16 © North Slope Training Cooperative—revised May All rights reserved. Why Static Electricity is Dangerous Personal injury from electric shock which can vary from a slight tingling sensation to immediate electrocution and result in: Burns and shrapnel wounds Blindness and hearing loss The severity of injury depends on the: Amount of current and its path through the body The length of time the body remains in the circuit The current’s frequency 16

17 17 © North Slope Training Cooperative—revised May All rights reserved. Why Static Electricity is Dangerous Damage to electrical equipment or electronic devices Risk of fire or explosion in a flammable atmosphere Gases or vapors Mists, dusts or fibers Hybrid mixtures of two or more flammable materials 17

18 18 © North Slope Training Cooperative—revised May All rights reserved. Why Static Electricity is Dangerous Static electricity is often the cause of fire and explosions when circumstances rule out other forms of ignition Steam cleaning equipment Tank-filling operations Using plastic containers for sampling Ventilating vessels or tanks 18

19 19 © North Slope Training Cooperative—revised May All rights reserved. Why Static Electricity is Dangerous Static electricity is often the cause of fire and explosions when circumstances rule out other forms of ignition Steam-cleaning equipment Tank filling operations Using plastic containers for sampling Ventilating vessels 19

20 20 © North Slope Training Cooperative—revised May All rights reserved. Static Build-up During Transfer Operations 20

21 21 © North Slope Training Cooperative—revised May All rights reserved. Control Measures 21

22 22 © North Slope Training Cooperative—revised May All rights reserved. Reducing the Hazards of Static Electricity 22 HazardsControl Measures Accumulation of static build-up Reduce build-up through the use of anti-static mats, clothing, and footwear, anti-static additives, grounding and bonding Electrostatic (spark) discharge Reduce chance of a discharge by the use of anti-static mats, clothing, and footwear, anti- static additives, grounding and bonding Ignitable atmosphereEliminate flammable atmospheres by eliminating vapor space, purging, or inerting

23 23 © North Slope Training Cooperative—revised May All rights reserved. Bonding is the process of connecting two or more conductive objects to each other by means of a conductor to minimize potential differences between conductive objects. Bonding equalizes the potential between objects. Bonding 23 BP ASH, pages ; 238

24 24 © North Slope Training Cooperative—revised May All rights reserved. Grounding is the process of connecting one or more conductive objects to the ground to minimize potential differences between objects and the ground. Grounding dissipates an electric charge to ground. Grounding 24 BP ASH, pages ; 241

25 25 © North Slope Training Cooperative—revised May All rights reserved. Bonding and Grounding This is an example of grounding two objects with the earth and bonding them to each other. 25 BP ASH, pages ; 238; 241

26 26 © North Slope Training Cooperative—revised May All rights reserved. Personal Protection An electrostatic discharge can injure workers and damage sensitive instrumentation and electronic devices. Use anti-static work bench and floor mats, anti-static wrist straps, clothing, and footwear to reduce the chance of an electrostatic discharge. 26

27 27 © North Slope Training Cooperative—revised May All rights reserved. Safe Work Practices 27

28 28 © North Slope Training Cooperative—revised May All rights reserved. Commercial Fuel Transfer Follow company procedures for fuel transfer. Procedures will vary according to the product being transferred. Tank trucks should be bonded to the fill system. 28 Connection of static bonding and grounding equipment to a tanker truck during the loading process ASH, pages ; BP ASH, pages 65-69

29 29 © North Slope Training Cooperative—revised May All rights reserved. Commercial Fuel Transfer All bonding and grounding should be in place prior to starting transfer operations. Use deflectors or drop tubes to avoid splashing during filling. Keep nozzle in contact with fill pipe while filling. 29 Connection of static bonding and grounding equipment to a tanker truck during the loading process ASH, pages ; BP ASH, pages 65-69

30 30 © North Slope Training Cooperative—revised May All rights reserved. Fueling Passenger Vehicles Static electricity can be highest during cold or dry conditions. Static build-up may occur if the driver re-enters the vehicle during fueling and then returns to the nozzle. If this occurs, discharge any potential static by touching a metal part of the vehicle with a bare hand before touching the nozzle again. 30

31 31 © North Slope Training Cooperative—revised May All rights reserved. Fueling Passenger Vehicles Leave your cell phone in the vehicle and focus on the task. Fuel slowly as higher velocity creates more static. If a fire occurs when refueling, leave the nozzle in the fill pipe, and back away from the vehicle. Notify someone immediately. 31

32 32 © North Slope Training Cooperative—revised May All rights reserved. Filling Portable Fuel Containers Use only approved portable fuel containers. Place the container on the ground while filling. Never fill a container while it is inside a vehicle, in the trunk, in the bed of a pickup or on the floor of a trailer. 32

33 33 © North Slope Training Cooperative—revised May All rights reserved. Filling Portable Fuel Containers Manually control the nozzle and fill the container slowly. Keep the nozzle in contact with the rim of the container opening while filling. Place cap tightly on the container after filling. Do not use containers that don’t seal properly. 33

34 34 © North Slope Training Cooperative—revised May All rights reserved. Transporting Portable Fuel Containers If gasoline spills on the container, make sure it has evaporated before it is placed in the vehicle. Report all spills to the filling station attendant. Secure the filled container against tipping or sliding back and forth while being transported. This type of movement can cause a build-up of static electricity inside or outside of the container. Never leave filled containers in direct sunlight or inside the vehicle. 34

35 35 © North Slope Training Cooperative—revised May All rights reserved. Summary Definition of Static Electricity Static Electricity Hazards Why Static Electricity is Dangerous Static Electricity Control Measures Safe Work Practices 35


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