1.
COMPRESSED GAS CYLINDERS - A
One of the most frequently observed violations of safety procedures is the misuse of
and careless attitude toward the handling of compressed gas cylinders. In the construction
industry, the gases most commonly used are in the form of oxygen and acetylene. Their use
is confined, primarily, to main plant operations, but are frequently used in the field.
During inspection tours, rare is the occasion that safe procedures are observed in the
handling and storing of cylinders.
The following suggestions
regarding the handling and storing of cylinders will contribute to a safer operation.
1.
Accept only cylinders approved for use in interstate
commerce (marked ICC).
Never accept cylinders not
provided with a valve
protection cap.
- Cylinders should be moved by means of a
hand truck or other mechanical means and never by magnetic crane. If absolutely necessary
to move them by hand, roll them on the bottom edge - never drag them.
- Do not drop or permit cylinders to strike
each other.
- Cylinders should always be stored securely
in an upright position.
- When empty cylinders are to be returned to
the vendor, mark them Empty or MT; close the valve and replace the valve protection cap.
- When in doubt, always consider cylinders
to be full and handle them accordingly. Accidents have resulted when containers under
partial pressure were thought to be empty.
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2.
COMPRESSED GAS CYLINDERS - B
Compressed gas cylinders are tricky things to handle. They are heavy; they are smooth
and hard to get a grip on: they have valves that can be easily damaged; and finally, they
are full of gas under pressure that can cause plenty of trouble if one gets loose in the
shop.
There have been many
cases of injury, death and heavy property damage caused by compressed gas cylinders,
becoming projectiles propelled at high speed by escaping gas when ruptured at the neck by
rough handling.
If you have to move a
cylinder a short distance, you can tip it and roll it along on the bottom edge. But never
drag it along the floor. Any rough handling that scratches or cuts the surface may cause
an accident later.
Don't try to carry a
cylinder by hand - not even with two men. Use a truck, or else a special carrying device.
Don't ever hoist one with
an electro.magnet or in a sling.
Treat the cylinders
gently. They may seem solid and strong, but a dropped cylinder, if not ruptured and turned
into a wild missile, may develop a weak spot that will let the gas escape. Don't bang them
together.
Try to move them and
handle them so as to avoid all unnecessary jolting and jarring.
Sometimes a guy is
tempted to use one or more of the gas cylinders as rollers, or to support something. Don't
do it – don’t ever use one for any other purpose than the one it was designed
for, the storage of gas.
Figure that every single
gas cylinder is full Sometimes you may think one is empty, and therefore safe, but
there may be enough pressure left in it to cause trouble.
Some kinds of cylinders
have what are called fusible plugs, that is, openings closed with a bit of metal with a
low melting point. In acetylene cylinders, the melting point is just about the boiling
point of water.
So, if you ever have to
thaw out a frozen valve on one of these, use warm, not boiling, water, and never,
under any circumstances, use flame to warm the valve or cylinder.
If a cylinder leaks, get
it outdoors as quickly as possible, some place well away from any flames or sparks. Notify
me at once. Post warning signs telling people to keep cigarettes and fires away from the
area. It is usually best to leave a valve slightly open so that the gas can escape
gradually.
Even if a cylinder is not
leaking, keep it away from sparks, molten metal, electric currents, great heat or flame.
It is just flirting with disaster to bring compressed gases in reach of such sources of
heat.
Here are some special
pointers on oxygen cylinders. Oxygen, you know, is the stuff in air that makes fires burn.
Pure oxygen is a lot better supporter of fire than air, and it can even start a fire where
no spark or ember exists - particularly if it comes in contact with oily material. So the
rule on oxygen cylinders is never to handle them with oily hands, gloves or clothing.
Never use or grease to lubricate valves or attachments on these cylinders. Keep the
cylinders away from oil and grease.
Never store oxygen cylinders near those
of flammable gases, and never try to use the oxygen for compressed air.
Gas cylinders are well made, and they are
safe if properly handled. But so is a gun or a stick of dynamite. Badly handled,
compressed gas cylinders can cause fires, explosions, or deaths.
So handle them carefully; don't bang them
around.
If you have any doubt about the way to
handle a cylinder, come to me before you try to move it.
Our business needs gas, and lots of it.
We're going to have to live and work with these cylinders for a long time. Let's learn to
live with them, and then we won't die from them!
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3. LP-
GAS HEATERS
LP-gas (propane, butane or mixture) is, in many cases, an indispensable fuel for
industrial space heating.
When use of portable
containers is necessary and their location outside of buildings or structures is
impracticable, containers and equipment may be used inside in accordance with the
provisions of NFPA Pamphlet 58 as are applicable to the particular use or occupancy. The
common sense rules in this bulletin should be applied for the safe use of LP-gas in such
instances.
Space heating refers to
the heat for personnel or other requirements and usually means infra-red heaters,
salamanders or standard space heaters.
Locate containers,
regulators, piping and hose where they will not be subjected to damage, tampering or
excessive temperature. Container valves should be protected from physical damage while in
use either by being recessed or by a suitable protective collar. Containers, in use, must
be upright and on a firm foundation or secured.
Do not drop containers.
Temporary space heating
units must be designed for use with LP-gas and should be listed by a nationally recognized
testing laboratory such as American Gas Association, Underwriters' Laboratories, Canadian
Gas Association and/or be acceptable to the authority having jurisdiction.
Heaters shall be located
at least 6 ft. from any LP-gas container. This shall not prohibit the use of heaters
specifically designed for attachment to the container or to a supporting standard,
providing they are designed and installed so as to prevent direct or radiant heat
application from the heater onto the container. Blower and radiant type heaters shall not
be directed toward any LP-gas container within 20 ft.
Containers not in use
should be stored upright, in a specified outside location and protected against damage or
tampering. Valves should be closed and protective collars in place.
When transporting
containers on a truck, forklift, etc., the containers should be firmly secured in an
upright position with valves closed and protective collar shall be in place.
For temporary inside
installations only approved containers such as ICC 26, ICC 4B-240 or ICC 4B-300 with a
maximum capacity of 100 lb. of LP-gas may be used. Each container shall be equipped with
an excess flow valve as an integral part of the container valve or in the connection to
the container valve outlet.
When heaters are
connected to containers for use in an unpartitioned area on the same floor, the total
LP-gas capacity of containers manifolded together for connection to a heater or heaters
shall not be greater than 300 lb. Such manifolds shall be separated from each other by at
least 20 ft.
Regulators, if used1 shall be
either directly connected to the container valves or to manifolds connected to the
container valves. The regulator shall be suitable for use with LP-gas. Manifolds and
fittings connecting containers to pressure regulator' inlets shall be designed for at
least 250 psig service pressure.
For flexible connection between the
regulator outlet and the heater, use only approved LP-gas hose of the shortest practical
length which should have a working pressure of at least 250 psig. Protect all hose from
damage and excessive heat. Heaters should be operated only where there is sufficient air
for combustion. Use only heaters or salamanders equipped with 100% safety shut-off valves
Do not use controls utilizing hi-metal strips.
Upon changing containers and making hose
connections, check all fittings for leaks with soap solution or other suitable leak
detector solution.
In addition to the
specific points covered below, all installations should comply fully with NFPA Pamphlet
58, "Storage and Handling of Liquefied Petroleum Gases, (Division I)" or
applicable local LP-gas regulations
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4. LP-
GAS LEAKS AND FIRE CONTROL
As in any emergency situation, it is of paramount importance to avoid endangering
human life in event of fire involving or exposing LP-Gas equipment, or serious leakage of
LP-Gas without fire.
BASIC PRECAUTIONS
1. Approach the fire or gas leak from unwind.
2. Keep all persons out
of vapor cloud area. If necessary to evacuate any area which is in the path of the vapor
cloud, do so immediately, eliminating all sources of ignition at the same time.
3. Police the area. Keep
all persons except those necessary to cope with the condition completely out of the area,
but in no case less than one to two thousand feet.
LEAKAGE WITHOUT
FIRE
1. If escaping LP-Gas is not burning, close any valve available that can stop the
flow of gas. Small lines such as copper tubing could be flattened to stop the flow. If an
LP-Gas vehicle is involved, consult the driver; or if storage facilities are involved,
consult plant personnel regarding possibilities of shutting off leaks.
2. Water spray is
effective in dispersing LP-Gas vapor. If available it should be used as soon as possible,
directing the spray stream across the normal vapor path and dispersing the vapor into a
safe location. Those handling the hose should avoid entering the vapor cloud and should
keep low behind the spray so that they will be somewhat protected from radiant heat if the
vapor should be ignited unexpectedly.
3, In some instances of
leakage from a tank without a fire, it may be desirable to move the tank to some remote
area such as a blocked-off isolated roadway or open field where it can leak safely away
from a source of ignition. However, if this is done, the tank should be moved only in an
upright position. Never drag the tank in a manner which might damage valves or piping. Any
attempt to turn a tank upright for moving it to some remote Location should be done
carefully to avoid damage to valves and piping, and preferably under cover of water spray.
LEAKAGE WITH FIRE
1.Do not extinguish unless leakage can be stopped, except under certain
conditions.
2.If the escaping gas is
on fire, apply large quantities of water as quickly as possible to all surfaces exposed to
heat. Approach the tank(s) from the sides. Concentrate on piping and metal surfaces of
vessels or adjoining vessels, equipment or combustible surfaces exposed to flame or
intense radiant heat, especially the upper position of the tank(s) shell (see Step No.7).
Ii a number of tanks are involved, use additional streams from the opposite sides for
adequate cooling.
3. Consult driver of
vehicle or plant operating personnel (as the case may be) regarding
possibilities of shutting
off fuel supply. Stopping the flow of gas should be the first consideration after water
cooling is established.
4. If the only valve that
can be used to stop the flow of fuel is involved in the fire, consider the possibility of
effecting shutoff by protecting firemen with water fog streams, protective clothing, and
gloves, while they are closing the valve. Proceed slowly to avoid any flashbacks or
trapping firemen in the flames.
5. The controlled burning
of escaping LP-Gas (which cannot be shut off by closing a valve) is a commonly accepted
fire-fighting practice. Application of sufficient water to keep the shell of the vessel
and piping cool will allow the fire to consume the product in the tank without danger of
causing failure.
6. Dry chemical portable extinguishers
are effective for extinguishing small LP-Gas fires. Extinguishing agent should be directed
toward point of vapor discharge. Carbon dioxide may also be used.
7. Failure of LP-Gas tanks usually occurs
only when some portion of the metal surface in the vapor space of the vessel becomes
overheated, softens and weakens to the point that it will not contain the pressure of the
product. In the absence of sufficient water to keep the metal surface cool where it is
exposed to direct flames or extreme radiant heat, there is danger of the tank rupturing.
PROTECT VAPOR AREA BY SPRAYING WATER.
SOMETIMES FROST LINE SHOWS LIQUID LEVEL.
8. When sufficient water is not available
to keep the tank cool, where excessive heat is present, some warning of increased pressure
may be noted from the increase in volume of the fire or of noise level. This should be a
signal to consider withdrawal of all men to a safe area.
9. Shooting holes in an
LP-Gas tank that is involved in fire does not serve any useful purpose and should not be
permitted.
10. Where possible,
remove container from area before flames of burning building reach the container. It may
be advisable to move the container under cover of water spray. It should be moved in only
an upright position. Never drag it in a manner that might further damage valves. Any
attempt to turn the tank upright to remove it to some remote location to facilitate
product withdrawal should be done carefully to avoid damage to valves and piping.
EXPOSURE TO FIRE
1. It is always important to control any exposure fire. In addition, when LP-Gas
storage vessels or equipment are subjected to serious fire exposure such as from a nearby
burning building or a fire involving another fuel, it is of prime importance to apply
sufficient water to keep the shell of the vessel and piping cool to avoid any unnecessary
release of LP-Gas.
2. If the LP-Gas storage
vessel becomes heated to the point of causing the relief valve to function, the discharge
should be allowed to burn if it becomes ignited. At the same time, continue to apply large
volumes of water to the vessel and piping to keep them cool and to allow the relief valve
to close after the excess pressure has been relieved.
3. Portable LP-Gas
cylinders that are exposed to a fire should be moved, if feasible, to a safe location.
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