Hydraulics

1
Hydraulics Safety Awareness
Dennis Mac HandS UK Health Safety Resources
2
Hydraulics is not a recognised occupational
hazard

• Unless there is a lost time injury or a death,
• hydraulic "accidents" go unreported
• Result no data
• No data no recognised problem

3
But there is a problem.

• Each of the cases illustrated here is an accident
  that could well occur in your company.
• The first step in preventing these, as with all
  types of accidents, is training.

4

• Hydraulic systems store fluid under high pressure
  typically, at 2,000 pounds per square inch
• Hazards
• stored energy
• flailing hydraulic hose, ejected components
• maintenance conducted without releasing pressure
• maintenance conducted after incorrectly releasing
  pressure
• temperature
• ignition
• injection

5
Employee Killed By Forklift Boom

• Employee 1 was unloading a piece of steel with
  his forklift. His supervisor leaned down to
  unhook a chain and saw hydraulic fluid dripping
  from the joint at the main cylinder he told
  Employee 1 to take the forklift to be fixed by
  the maintenance man. The employee parked the
  forklift in the maintenance area and raised the
  forks. Employee 1 was standing under the forks
  when the hydraulic fitting to the mast failed,
  resulting in a sudden release of the fluid and
  descent of the mast. Employee 1 was killed. No
  one saw the accident. He may have been attempting
  to pinpoint the leak's location prior to
  summoning the maintenance man. There was a wrench
  on the floor near the body, and it is likely that
  Employee 1 was attempting to tighten the fitting
  to stop the leak, but instead stripped the
  threads, causing a complete failure.

OSHA Accident 515205 Report ID 0625700 -- Event
Date 09/18/1990
6

• Skin will scald at 48C (120F)
• Two to three minutes at that temperature will
  result in a 2nd degree burn.
• The average operating temperature of a hydraulic
  system of 60C
• will cause a 2nd degree burn in
• ½ to 1 second.

7

• Oil adheres to the skin. The longer the contact,
  the deeper the burn. Burn injuries are the worst
  type of injury from a rehabilitation point of
  view. The rule of thumb is one day in hospital
  for each 1 of body area burned.

8

• This operator was burned when a hydraulic hose,
  neglected during maintenance, burst and spewed
  hydraulic oil, at normal operating temperature,
  over his entire body.

9
Fire and Explosion Risks

• High flash point 145-315C (300-600F)
• High auto-ignition 260-400C (500-750F)
• Under pressure, atomised spray of droplets may
  extend 10 metres from the break
• Ignited readily by heat source
• Resulting fire is torch-like with very high heat
  release rate
• Mist in confined area can explode violently

10
Welder Strikes Hydraulic Fluid And Is Burned To
Death

• Employee 1 was arc welding in the forward
  ballast tank of the American Trader vessel,
  working approximately 68 feet from the upper deck
  in an enclosed space. His welding rod struck a
  pipeline containing hydraulic fluid, which was
  under approximately 600 psig at the time, and
  ignited a fire. Employee 1 became engulfed in
  flames, and sustained thermo-cutaneous burns over
  80 percent of his body from which he died.

OSHA Accident 967430 Report ID 0932000 --
Event Date 07/18/1991
11
Two Employees Burned In Flash Fire

• Employees 1 and 2, both press operators, were
  operating an aluminum extrusion press when a
  hydraulic hose developed a leak. Hydraulic fluid
  sprayed out in a small stream under pressure and
  then partially vapourised. The heat and flame
  from a nearby oven ignited the fluid, resulting
  in a flash fire. Employees 1 and 2 sustained
  second- and third-degree burns.

OSHA Accident 170587760 Report ID 0950631 --
Event Date 02/19/1996
12

• Imagine a chip pan fire
• Projected from a high-pressure nozzle

13
The frequency of fires involving hydraulic fluids
has prompted the introduction of fire-resistant
fluids for hydraulic systems.

• Is your company using them?

14
Never heat or weld on or near hydraulic
components without proper preparation.
RISK ASSESSMENT

• For every 1 degree in heat
• applied to trapped hydraulic oil,
• the pressure rises 50-
• to 60-pounds-per-square-inch.

15
Employee Dies In Oil Drum Explosion

• Employee 1 was cutting the top out of a 55
  gallon metal drum that had contained hydraulic
  oil. The drum exploded, killing the employee.

OSHA Accident 170568448 Report ID 0751910 --
Event Date 06/09/1995
16

• Never use hands or fingers
• to find leaks.
• Fluid under high pressure can be injected into
  the skin causing extreme injury, serious
  infection
• gangrene
• and amputation.

17
Accidental Injection of Hydraulic Oil
18

• Pipe being pressure-tested in rig with OM15
  aircraft hydraulic oil, held at 6,000psi
• As operator reached inside Perspex box to operate
  pressure relief valve, hand brushed against pipe
  to valve, just as the pipe split.
• Fine jet of oil made a ¼-inch cut in hand, with
  ½-inch circle of lifted skin around it.
• Felt like being punched in the palm.
• No pain

19

• Rushed to hospital in company security van
• Pain increasing intravenous pain relief
• In surgery 5 hours after incident, began removing
  oil
• After surgery, morphine ineffective for pain
  relief
• With local anaesthetic to hand, undid stitches
  and searched for more oil
• Second surgery on day three

20

• Skin turned black on little finger
• Carpal tunnel opened to relieve pressure
• Massive swelling crushing nerves
• Cut away side of hand eaten by oil
• Third surgery on day five
• More flesh cut away and grafts begun
• Drugs for pain finally working

21
(No Transcript)
22

• 14 days in hospital
• Weekly physiotherapy
• 3 months later, fourth surgery to release little
  finger that had curled into palm
• 9 months later, fifth surgery
• Off work for six months
• 3 skin grafts with scarring to thigh and arm
• 2 years of physiotherapy
• Marriage break-up

23
(No Transcript)
24
Pipe, retrieved from dismantled test rig
25
Working with Hydraulic Oils

• Avoid prolonged breathing of its vapour, mist,
  and fumes.
• Avoid prolonged or repeated skin contact.
• Use chemical-resistant gloves, splash goggles and
  a chemical-resistant apron
• Elevated processing temperatures may cause
  release of toxic vapours which are harmful if
  inhaled.
• Before working with hydraulic oil, know the
  location of the nearest emergency shower and
  eyewash station.

26

• Wash off affected skin, eyes, and protective
  clothing immediately. Remove contaminated
  clothing, and launder or dry-clean it before
  reuse.
• After contact with hydraulic oil (and especially
  before breaks and meals, and at the end of
  shifts), always cleanse skin with a waterless
  hand cleanser, and then wash with soap and water.

27
Working with Hydraulic Systems

•   Never begin work on a hydraulic system until
  fully trained.
• Never begin work on a hydraulic system without
• a Risk Assessment.
•   Carefully review the manuals on equipment
  before beginning work. Ask questions about
  anything you do not fully understand.
• Review all Material Safety Data Sheets (MSDS) for
  all chemicals used.
• Maintain a clean work area free of slipping
  hazards and debris.
•   Use all required safety equipment.

28

•   Block, secure or lower to the ground
  components that may move, rotate or fall.
• Use test equipment designed for higher pressures
  than the system being repaired. Use of gauges,
  lines, connectors, etc., designed for lower
  pressures can result in bursting or equipment
  damage. Start with high pressure gauges and work
  down. (A good rule is to use equipment rated at
  twice what is expected. Example For a 2500 psi
  system, use a 5000 psi gauge.)
• Relieve system pressures.
• DO NOT USE FINGERS OR HANDS to find leaks. Check
  for leaks using a piece of cardboard or wood.

29

•   Always use safety glasses.
• Use extreme caution when disconnecting hydraulic
  lines. Severe burns from hot fluid can result.
• Clean up spills immediately. Hydraulic fluid can
  cause slips, falls and resulting injuries.
• Do not work under equipment / apparatus being
  supported by hydraulics. Stops, safety pins, etc,
  must be in place before repairs begin.
• AVOID HEATING NEAR PRESSURISED FLUID LINES.

30
Hydraulics Maintenance

• All hydraulic hoses, tube lines and fittings
  should be periodically inspected.
• Any deterioration should be carefully examined to
  determine whether further use of the component
  would constitute a hazard.

31

• Conditions such as the following should be
  sufficient for consideration of replacement
•      a. Any evidence of hydraulic oil leakage
  at the surface of a flexible hose or its junction
  with the metal and couplings      b. Any
  blistering or abnormal deformation to the outer
  covering of a hydraulic hose      c. Hydraulic
  oil leakage at any threaded or clamped joint that
  cannot be eliminated by normal tightening or
  recommended procedures

32

• and/or      d. Evidence of excessive abrasion or
  scrubbing on the outer surface of a hose, rigid
  tube, or hydraulic fitting.

33
Summary

• The risks of work with hydraulic systems are not
  only of high-pressure puncture accidents, but of
  fire, lacerations, severe burns, crushing and
  death.
• These risks apply not only to test-bed engineers,
  but to maintenance fitters, forklift and lorry
  fitters, millwrights, platers and welders and to
  anyone whose work entails the operation of
  machines whether they be milling machines or
  bulldozers that use hydraulic pressure systems.

34
RISK ASSESSMENT

• All maintenance work should be visually examined
  when Risk Assessed.
• All "hot work" should be visually examined when
  Risk Assessed.
• the presence of a hydraulic system is a hazard
• the presence of hydraulic hoses is a hazard

35
Remember?

• Step 1 Look for the hazards
• Step 2 Decide who might be harmed and how
• Step 3 Evaluate the risks and decide whether
• the existing precautions are adequate or whether
  more should be done
• Step 4 Record your findings
• Step 5 Review your assessment and revise it if
  necessary

HSE, 5 Steps to Risk Assessment, INDG 163
36

• Poor skills, not poor employees, are the
  root-cause of most accidents associated with
  hydraulics.
• There is no tool more effective at eliminating
  poor skills and hence, work-related accidents,
  than training.

37

• Ensure that only trained, authorised persons
  carry out hydraulic system service, repair and
  troubleshooting.
• Encourage discussion in management and in safety
  committees on the need for training that will
  prevent these kinds of accidents occurring to
  those to work near or with hydraulic systems.

38

• Get training
• for competency in hydraulics
• Get training
• - not in the theory of hydraulics -
• but in the hazards of hydraulics

39
Hydraulics Safety Awareness
Thank you
Dennis Mac HandS UK Health Safety Resources