296-307-475 Welding, cutting, and brazing.
296-307-47501 What definitions apply to this part?
296-307-480 Installation and operation of oxygen fuel gas systems
for welding and cutting.
296-307-48001 What general requirements apply to oxygen fuel gas systems?
296-307-48003 What requirements apply to portable cylinders?
296-307-48005 What general requirements apply to storing compressed
gas cylinders?
296-307-48007 How must fuel-gas cylinders be stored?
296-307-48009 How must oxygen cylinders be stored?
296-307-48011 What general operating procedures apply to working with
cylinders and containers?
296-307-48013 What requirements apply to safety devices on cylinders?
296-307-48015 How must cylinders be transported?
296-307-48017 How must cylinders be handled?
296-307-48019 What requirements apply to cylinder valves?
296-307-48021 What requirements apply to cylinder regulators?
296-307-48023 What requirements apply to fuel-gas manifolds?
296-307-48025 What requirements apply to high pressure oxygen manifolds?
296-307-48027 What requirements apply to low pressure oxygen manifolds?
296-307-48029 What requirements apply to manifolding portable outlet
headers?
296-307-48031 What operating procedures apply to cylinder manifolds?
296-307-48033 How must service piping systems be designed?
296-307-48035 What requirements apply to piping joints?
296-307-48037 How must service piping systems be installed?
296-307-48039 How must service piping systems be painted and marked?
296-307-48041 How must service piping systems be tested?
296-307-48043 How must equipment be installed?
296-307-48045 How must service piping systems be protected?
296-307-48047 What requirements apply to piping protective equipment?
296-307-48049 What requirements apply to station outlet protective
equipment?
296-307-48051 What requirements apply to hose and hose connections?
296-307-48053 What requirements apply to pressure-reducing regulators?
296-307-485 Installation and operation of resistance welding equipment.
296-307-48501 What general requirements apply to resistance welding
equipment?
296-307-48503 What requirements apply to portable welding machines? 296-307-48505 What requirements apply to flash welding equipment?
296-307-48507 Who must perform a job hazard analysis?
296-307-48509 What maintenance requirements apply to resistance welding
equipment?
296-307-490 Application, installation, and operation of arc welding
and cutting equipment.
296-307-49001 What environmental conditions must be taken into account
when selecting arc welding equipment?
296-307-49003 What voltages must arc welding equipment use?
296-307-49005 How must arc welding equipment be designed?
296-307-49007 How must arc welding equipment be installed?
296-307-49009 How must arc welding equipment be grounded?
296-307-49011 What requirements apply to supply connections and conductors?
296-307-49013 How must arc welding equipment be operated?
296-307-49015 How must arc welding equipment be maintained?
296-307-495 Fire prevention and protection.
296-307-49501 What basic fire prevention precautions must be taken?
296-307-49503 What special fire prevention precautions must be taken?
296-307-49505 What precautions must be taken when welding or cutting
containers?
296-307-49507 What precautions must be taken when welding in confined
spaces?
296-307-500 Protection of employees.
296-307-50001 How must eye protection be selected?
296-307-50003 What specifications must eye protection meet?
296-307-50005 What protective clothing must welders wear?
296-307-50007 What other requirements apply to employee protection?
296-307-50009 What employee protection must be provided in confined
spaces?
296-307-50011 What general requirements apply to welding ventilation?
296-307-50013 What ventilation must be provided for general welding
and cutting?
296-307-50015 What requirements apply to local exhaust hoods and booths?
296-307-50017 What ventilation must be provided in confined spaces?
296-307-50019 What requirements apply to welding fluorine compounds?
296-307-50021 What requirements apply to welding zinc?
296-307-50023 What requirements apply to welding lead?
296-307-50025 What requirements apply to welding beryllium?
296-307-50027 What requirements apply to welding cadmium?
296-307-50029 What requirements apply to welding mercury?
WAC 296-307-48001
What general requirements apply to oxygen fuel gas systems?
(1) Explosive mixtures of fuel gases and air or oxygen must be guarded
against. No accessory that allows air or oxygen to mix with flammable
gases prior to use must be allowed unless approved for that purpose.
Exception: Air or oxygen may mix with flammable
gases at the burner or in a standard torch.
(2) Acetylene must never be generated, piped (except in approved cylinder
manifolds) or used at a pressure in excess of 15 psi gauge pressure or
30 psi absolute pressure. (The 30 psi absolute pressure limit is intended
to prevent unsafe use of acetylene in pressurized chambers such as caissons,
underground excavations or tunnel construction.) Using liquid acetylene
is prohibited.
Exception: This requirement does not apply to storage
of acetylene dissolved in a suitable solvent in cylinders manufactured
and maintained according to DOT requirements, or to acetylene for chemical
use.
(3) Only approved apparatus such as torches, regulators or pressure-reducing
valves, acetylene generators, and manifolds must be used. Replacement
tips may be used on approved torches, if the replacement tips are made
to the same specifications as the original, or when replacements are used
with convertor/adaptors that meet the same specifications.
(4) Before leaving any employee in charge of the oxygen or fuel-gas supply
equipment, including generators, and oxygen or fuel-gas distribution piping
systems, you must ensure that the employee has received proper instruction
and is competent to do the work. Rules and instructions covering the operation
and maintenance of oxygen or fuel-gas supply equipment including generators,
and oxygen or fuel-gas distribution piping systems must be readily available.
All portable cylinders used for storing and shipping compressed gases
must be constructed and maintained according to DOT regulations.
(1) Compressed gas cylinders must be legibly marked with either the chemical
or the trade name of the gas. The marking must be a permanent stencil,
stamp, or label. Whenever practical, the marking must be located on the
shoulder of the cylinder.
(2) Compressed gas cylinders must have connections that meet the requirements
of the American National Standard Compressed Gas Cylinder Valve Outlet
and Inlet Connections, ANSI B 57.1-1965.
(3) All cylinders with a water weight capacity greater than thirty pounds
must have means of connecting a valve protection cap or with a collar
or recess to protect the valve.
WAC 296-307-48005
What general requirements apply to storing compressed gas cylinders?
(1) Cylinders must be kept away from radiators and other sources of heat.
(2) Indoors, cylinders must be stored in a well-protected, well-ventilated,
dry area, at least twenty feet from highly combustible materials such
as oil or excelsior. Cylinders should be stored in assigned places away
from elevators, stairs, or gangways. Assigned storage spaces must be located
where cylinders will not be knocked over or damaged by passing or falling
objects, or subject to tampering. All cylinder enclosures must be ventilated.
(3) Empty cylinders must have their valves closed.
(4) Valve protection caps on cylinders designed to accept a cap, must
always be in place and hand-tight, except when cylinders are in use or
connected for use.
Cylinders stored indoors, except those in use or attached ready for use,
must be limited to a total gas capacity of 2,000 cubic feet or 300 pounds
of LP-gas.
(1) Cylinders in excess of 2,000 cubic feet total gas capacity or 300
pounds of LP-gas, must be stored in a separate room or compartment that
meets the requirements of 252 (a)(8) and (9) CFR, or cylinders must be
kept outside or in a special building. Special buildings, rooms or compartments
must be free from open flame for heating or lighting and must be well
ventilated. They may also be used for storage of a maximum of 600 pounds
of calcium carbide, when contained in metal containers complying with
252 (a)(7)(a) and (b) CFR. Signs should be conspicuously posted in such
rooms reading, “Danger-No smoking, matches or open lights,” or other equivalent
wording.
(2) Acetylene cylinders must be stored valve end up.
(1) Oxygen cylinders must not be stored near highly combustible material,
especially oil and grease; or near reserve stocks of carbide and acetylene
or other fuel-gas cylinders, or near any other substance likely to cause
or accelerate fire; or in an acetylene generator compartment.
(2) Oxygen cylinders stored in outside generator houses must be separated
from the generator or carbide storage rooms by a noncombustible partition
having a fire-resistance rating of at least one hour. This partition must
be without openings and must be gastight.
(3) Oxygen cylinders in storage must be separated from fuel-gas cylinders
or combustible materials (especially oil or grease), a minimum of 20 feet
or by a noncombustible barrier at least five feet high having a fire-resistance
rating of at least one-half hour. (Cylinders “in-use,” secured to a hand
truck or structural member, with regulators, hoses, and torch temporarily
removed for security purposes overnight or weekends, are not considered
“in-storage.”)
(4) Where a liquid oxygen system is to be used to supply gaseous oxygen
for welding or cutting and the system has a storage capacity of more than
13,000 cubic feet of oxygen (measured at 14.7 psi(a) and 70°F), connected
in service or ready for service, or more than 25,000 cubic feet of oxygen
(measured at 14.7 psi(a) and 70°F), including unconnected reserves on
hand at the site, it must meet the requirements of the Standard for Bulk
Oxygen Systems at Consumer Sites, NFPA No. 566-1965.
WAC 296-307-48011
What general operating procedures apply to working with cylinders and
containers?
(1) The numbers and markings stamped into cylinders must not be tampered
with.
(2) Cylinders, cylinder valves, couplings, regulators, hose, and apparatus
must be kept free from oily or greasy substances. Oxygen cylinders or
apparatus must not be handled with oily hands or gloves. A jet of oxygen
must never be permitted to strike an oily surface, greasy clothes, or
enter a fuel oil or other storage tank.
(3) Cylinders must be kept far enough away from the actual welding or
cutting operation so that sparks, hot slag, or flame will not reach them,
or fire-resistant shields must be provided.
(4) No person, other than the gas supplier, may attempt to mix gases
in a cylinder. No one, except the owner of the cylinder or person authorized
by the owner, may refill a cylinder.
(5) Cylinders must not be placed where they might become part of an electric
circuit. Contacts with third rails, trolley wires, etc., must be avoided.
(6) Fuel-gas cylinders must be placed with valve end up whenever they
are in use. Liquefied gases must be stored and shipped with the valve
end up.
(7) A suitable cylinder truck, chain, or other steadying device must
be used to prevent cylinders from being knocked over while in use.
WAC 296-307-48013
What requirements apply to safety devices on cylinders?
(1) Valve-protection caps must not be used for lifting cylinders from
one vertical position to another. Bars must not be used under valves or
valve-protection caps to pry cylinders loose when frozen to the ground
or otherwise fixed; we recommend using warm (not boiling) water. Valve-protection
caps are designed to protect cylinder valves from damage.
(2) Cylinders without fixed hand wheels must have keys, handles, or nonadjustable
wrenches on valve stems while these cylinders are in service. In multiple
cylinder installations only one key or handle is required for each manifold.
(3) No one may tamper with safety devices in cylinders or valves.
(4) Nothing may be placed on top of an acetylene cylinder when in use
that may damage the safety device or interfere with the quick closing
of the valve.
(5) Where a special wrench is required it must be left in position on
the stem of the valve while the cylinder is in use so that the fuel-gas
flow can be quickly turned off in case of emergency. In the case of manifolded
or coupled cylinders at least one such wrench must always be available
for immediate use.
(6) Cylinders with leaking fuse plugs or other leaking safety devices
should be plainly marked with a warning not to approach them with a lighted
cigarette or other source of ignition. You should notify the supplier
promptly and follow the supplier's instructions as to their return.
(1) When transporting cylinders by a crane or derrick, a cradle, boat,
or suitable platform must be used. Slings or electric magnets are prohibited
for this purpose. Valve-protection caps, where cylinder is designed to
accept a cap, must always be in place.
(2) Unless cylinders are secured on a special truck, regulators must
be removed and valve-protection caps, when provided for, must be put in
place before cylinders are moved.
(3) When cylinders are transported by powered vehicle they must be secured
in a vertical position.
(1) Cylinders must not be dropped or struck or permitted to strike each
other violently.
(2) Cylinders must be handled carefully. Cylinders must not be subjected
to rough handling, knocks, or falls that are liable to damage the cylinder,
valve or safety devices and cause leakage.
(3) Cylinders must never be used as rollers or supports, whether full
or empty.
(1) Cylinder valves must be closed before moving cylinders
(2) Cylinder valves must be closed when work is finished.
(3) Valves of empty cylinders must be closed.
(4) A hammer or wrench must not be used to open cylinder valves. If valves
cannot be opened by hand, the supplier must be notified.
(5) Cylinder valves must not be tampered with nor should any attempt
be made to repair them. If you have trouble with a cylinder, you should
send a report to the supplier indicating the character of the trouble
and the cylinder's serial number. You must follow the supplier's instructions
on what to do with the cylinder.
(6) Complete removal of the stem from a diaphragm-type cylinder valve
must be avoided.
(7) If cylinders are found to have leaky valves or fittings that cannot
be stopped by closing of the valve, the cylinders must be taken outdoors
away from sources of ignition and slowly emptied.
(8) The cylinder valve must always be opened slowly.
(9) An acetylene cylinder valve must not be opened more than one and
one-half turns of the spindle, and preferably no more than three-fourths
of a turn.
(1) Unless connected to a manifold, oxygen from a cylinder must first
have an oxygen regulator attached to the cylinder valve.
(2) Before connecting a regulator to a cylinder valve, the valve must
be opened slightly and closed immediately. The valve must be opened while
standing to one side of the outlet; never in front of it. Fuel-gas cylinder
valves must not be cracked near other welding work or near sparks, flame,
or other possible sources of ignition.
(3) Before a regulator is removed from a cylinder valve, the cylinder
valve must be closed and the gas released from the regulator.
(4) Fuel-gas must not be used from cylinders through torches or other
devices equipped with shut-off valves without reducing the pressure through
a suitable regulator attached to the cylinder valve or manifold.
(1) Manifolds must be approved either separately for each component part
or as an assembled unit.
(2) Fuel-gas cylinders connected to one manifold inside a building must
be limited to a maximum total capacity of 300 pounds of LP-gas or 3,000
cubic feet of other fuel-gas. More than one such manifold with connected
cylinders may be located in the same room if the manifolds are at least
50 feet apart or separated by a noncombustible barrier at least 5 feet
high having a fire-resistance rating of at least one-half hour.
(3) Exception: Fuel-gas cylinders connected to one manifold having an
aggregate capacity exceeding 300 pounds of LP-gas or 3,000 cubic feet
of other fuel-gas must be located outdoors, or in a separate building
or room constructed according to 252 (a)(8) and (9) CFR.
(4) Separate manifold buildings or rooms may also be used for the storage
of drums of calcium carbide and cylinders containing fuel gases
as provided in WAC
296-307-48007. Such buildings or rooms must have no open flames
for heating or lighting and must be well ventilated.
(5) High-pressure fuel-gas manifolds must have approved pressure regulating
devices.
WAC 296-307-48025
What requirements apply to high pressure oxygen manifolds?
This section applies to cylinders with a DOT service pressure above
200 psig.
(1) Manifolds must be approved either separately for each component or
as an assembled unit.
(2) Oxygen manifolds must not be located in an acetylene generator room.
Oxygen manifolds must be separated from fuel-gas cylinders or combustible
materials (especially oil or grease), a minimum distance of 20 feet or
by a noncombustible barrier at least 5 feet high having a fire-resistance
rating of at least one-half hour.
(3) Oxygen cylinders connected to one manifold must be limited to a total
gas capacity of 6,000 cubic feet. More than one such manifold with connected
cylinders may be located in the same room if the manifolds are at least
50 feet apart or separated by a noncombustible barrier at least 5 feet
high having a fire-resistance rating of at least one-half hour.
(4) Exception: An oxygen manifold, to which cylinders having an aggregate
capacity of more than 6,000 cubic feet of oxygen are connected, should
be located outdoors or in a separate noncombustible building. Such a manifold,
if located inside a building having other occupancy, must be located in
a separate room of noncombustible construction having a fire-resistance
rating of at least one-half hour or in an area with no combustible material
within 20 feet of the manifold.
(5) An oxygen manifold or oxygen bulk supply system that has storage
capacity of more than 13,000 cubic feet of oxygen (measured at 14.7 psia
and 70°F), connected in service or ready for service, or more than 25,000
cubic feet of oxygen (measured at 14.7 psia and 70°F), including unconnected
reserves on hand at the site, must meet the requirements of the Standard
for Bulk Oxygen Systems at Consumer Sites, NFPA No. 566-1965.
(6) High-pressure oxygen manifolds must have approved pressure-regulating
devices.
WAC 296-307-48027
What requirements apply to low pressure oxygen manifolds?
This section applies to cylinders with a maximum DOT service pressure
of 200 psig.
(1) Manifolds must be of substantial construction suitable for use with
oxygen at a pressure of 250 psig. They must have a minimum bursting pressure
of 1,000 psig and must be protected by a safety-relief device that will
relieve at a maximum pressure of 500 psig.
Note: DOT-4L200 cylinders have safety devices that
relieve at a maximum pressure of 250 psig (or 235 psig if vacuum insulation
is used).
(2) Hose and hose connections subject to cylinder pressure must meet
the requirements of WAC
296-307-48049. Hose must have a minimum bursting pressure
of 1,000 psig.
(3) The assembled manifold including leads must be tested and proven
gas-tight at a pressure of 300 psig. The fluid used for testing oxygen
manifolds must be oil-free and not combustible.
(4) The location of manifolds must meet the requirements of WAC
296-307-48025.
(5) The following sign must be conspicuously posted at each manifold:
Low-Pressure Manifold
Do Not Connect High-Pressure Cylinders
WAC 296-307-48029
What requirements apply to manifolding portable outlet headers?
(1) Portable outlet headers must not be used indoors except for temporary
service where the conditions preclude a direct supply from outlets located
on the service piping system.
(2) Each outlet on the service piping from which oxygen or fuel-gas is
withdrawn to supply a portable outlet header must have a readily accessible
shut-off valve.
(3) Hose and hose connections used for connecting the portable outlet
header to the service piping must meet the requirements of WAC
296-307-48051.
(4) Master shut-off valves for both oxygen and fuel-gas must be provided
at the entry end of the portable outlet header.
(5) Portable outlet headers for fuel-gas service must have an approved
hydraulic back-pressure valve installed at the inlet and preceding the
service outlets, unless an approved pressure-reducing regulator, an approved
backflow check valve, or an approved hydraulic back-pressure valve is
installed at each outlet. Outlets provided on headers for oxygen service
may be fitted for use with pressure-reducing regulators or for direct
hose connection.
(6) Each service outlet on portable outlet headers must have a valve
assembly that includes a detachable outlet seal cap, chained or otherwise
attached to the body of the valve.
(8) Portable outlet headers must have frames that will support the equipment
securely in the correct operating position and protect them from damage
during handling and operation.
WAC 296-307-48031
What operating procedures apply to cylinder manifolds?
(1) Cylinder manifolds must be installed under the supervision of someone
familiar with the proper practices of construction and use.
(2) All component parts used in the methods of manifolding described
in WAC
296-307-48023 must have the materials, design and construction
approved either separately or as an assembled unit.
(3) All manifolds and parts used in methods of manifolding must be used
only for the gas or gases for which they are approved.
(4) When acetylene cylinders are coupled, approved flash arresters must
be installed between each cylinder and the coupler block. For outdoor
use only, and when the number of cylinders coupled does not exceed three,
one flash arrester installed between the coupler block and regulator is
acceptable.
(5) Each fuel-gas cylinder lead should have a backflow check valve.
(6) The maximum aggregate capacity of fuel-gas cylinders connected to
a portable manifold inside a building must be 3,000 cubic feet of gas.
(7) Acetylene and liquefied fuel-gas cylinders must be manifolded vertically.
(8) The pressure in the gas cylinders connected to and discharged simultaneously
through a common manifold must be approximately equal.
(1) Piping and fittings must comply with Section 2, Industrial Gas and
Air Piping Systems, of the American National Standard Code for Pressure
Piping, ANSI B 31.1-1967, if they do not conflict with subsections (2)
and (3) of this section.
(2) Pipe must be at least Schedule 40 and fittings must be at least standard
weight in sizes up to and including 6-inch nominal.
(3) Copper tubing must be Types K or L according to the Standard Specification
for Seamless Copper Water Tube, ASTM B88-66a.
(4) Piping must be steel, wrought iron, brass or copper pipe, or seamless
copper, brass or stainless steel tubing, except as provided in subsections
(5) through (9) of this section.
(5) Oxygen piping and fittings at pressures in excess of 700 psig, must
be stainless steel or copper alloys.
(6) Hose connections and hose complying with WAC
296-307-48051 may be used to connect the outlet of a manifold
pressure regulator to piping if the working pressure of the piping
is 250 psig or less and the length of the hose is a maximum of
5 feet. Hose must have a minimum bursting pressure of 1,000 psig.
(7) When oxygen is supplied to a service piping system from a low-pressure
oxygen manifold without an intervening pressure regulating device, the
piping system must have a minimum design pressure of 250 psig. A pressure
regulating device must be used at each station outlet when the connected
equipment is for use at pressures less than 250 psig.
(8) Piping for acetylene or acetylenic compounds must be steel or wrought
iron.
(9) Unalloyed copper must only be used for acetylene or acetylenic compounds
in listed equipment.
(1) Joints in steel or wrought iron piping must be welded, threaded or
flanged. Fittings, such as ells, tees, couplings, and unions, must be
rolled, forged or cast steel, malleable iron or nodular iron. Gray or
white cast iron fittings are prohibited.
(2) Joints in brass or copper pipe must be welded, brazed, threaded,
or flanged. Socket type joints must be brazed with silver-brazing alloy
or similar high melting point (not less than 800°F) filler metal.
(3) Joints in seamless copper, brass, or stainless steel tubing must
be approved gas tubing fittings or the joints must be brazed. Socket type
joints must be brazed with silver-brazing alloy or similar high melting
point (not less than 800°F) filler metal.
(1) Distribution lines must be installed and maintained in a safe operating
condition.
(2) Piping may be above or below ground. All piping must be run as directly
as practical, protected against physical damage, with an allowance for
expansion and contraction, jarring and vibration. Pipe laid underground
in earth must be below the frost line and protected against corrosion.
After assembly, piping must be thoroughly blown out with air or nitrogen
to remove foreign materials. For oxygen piping, only oil-free air, oil-free
nitrogen, or oil-free carbon dioxide must be used.
(3) Only piping that has been welded or brazed must be installed in tunnels,
trenches or ducts. Shut-off valves must be located outside such conduits.
Oxygen piping may be placed in the same tunnel, trench or duct with fuel-gas
pipelines, if there is good natural or forced ventilation.
(4) Low points in piping carrying moist gas must be drained into drip
pots constructed to permit pumping or draining out the condensate at necessary
intervals. Drain valves must be installed for this purpose having outlets
normally closed with screw caps or plugs. Open end valves or petcocks
are prohibited, except that in drips located outdoors, underground, and
not readily accessible, valves may be used at such points if they have
means to secure them in the closed position. Pipes leading to the surface
of the ground must be cased or jacketed where necessary to prevent loosening
or breaking.
(5) Gas cocks or valves must be provided for all buildings at points
where they will be readily accessible for shutting off the gas supply
to these buildings in any emergency. Underground valve boxes or manholes
should be avoided wherever possible. There must be a shut-off valve in
the discharge line from the generator, gas holder, manifold or other source
of supply.
(6) Shut-off valves must not be installed in safety-relief lines in such
a manner that the safety-relief device can be rendered ineffective.
(7) Fittings and lengths of pipe must be examined internally before assembly
and, if necessary, freed from scale or dirt. Oxygen piping and fittings
must be washed out with a suitable solution that will effectively remove
grease and dirt but will not react with oxygen.
Note: Hot water solutions of caustic soda or trisodium
phosphate are effective for this purpose.
(8) Piping must be thoroughly blown out after assembly to remove foreign
materials. For oxygen piping, oil-free air, oil-free nitrogen, or oil-free
carbon dioxide must be used. For other piping, air or inert gas may be
used.
(9) When flammable gas lines or other parts of equipment are being purged
of air or gas, open lights or other sources of ignition are prohibited
near uncapped openings.
(10) No welding or cutting must be performed on an acetylene or oxygen
pipeline, including the attachment of hangers or supports, until the line
has been purged. Only oil-free air, oil-free nitrogen, or oil-free carbon
dioxide must be used to purge oxygen lines.
WAC 296-307-48039
How must service piping systems be painted and marked?
(1) Underground pipe and tubing and outdoor ferrous pipe and tubing must
be covered or painted with a suitable material for protection against
corrosion.
(2) Aboveground piping systems must be marked according to the American
National Standard Scheme for the Identification of Piping Systems, ANSI
A 13.1-1956.
(3) Station outlets must be marked to indicate the name of the gas.
(1) Piping systems must be tested and proved gastight at 1-1/2 times
the maximum operating pressure, and must be thoroughly purged of air before
being placed in service. The material used for testing oxygen lines must
be oil free and noncombustible. Flames must not be used to detect leaks.
(2) When flammable gas lines or other parts of equipment are being purged
of air or gas, sources of ignition are prohibited near uncapped openings.
Service piping systems must be protected by pressure relief devices
set to function at not more than the design pressure of the systems and
discharging upwards to a safe location.
WAC 296-307-48047
What requirements apply to piping protective equipment?
(1) The fuel-gas and oxygen piping systems, including portable outlet
headers must incorporate the protective equipment shown in Figures V-1,
V-2, and V-3.
When only a portion of a fuel-gas system is to be used with oxygen, only
that portion must meet this requirement.
(2) Approved protective equipment (designated PF in Figs. V-1, V-2, and
V-3) must be installed in fuel-gas piping to prevent:
(a) Backflow of oxygen into the fuel-gas supply system;
(b) Passage of a flash back into the fuel-gas supply system; and
(c) Excessive back pressure of oxygen in the fuel-gas supply system.
The three functions of the protective equipment may be combined in one
device or may be provided by separate devices.
PF =
Protective equipment in fuel-gas piping VF = Fuel-gas station outlet
valve VO = Oxygen station outlet valve SF = Backflow prevention
device(s) at fuel-gas
station outlet
SO = Backflow prevention device(s) at oxygen station
outlet
(3) The protective equipment must be located in the main supply line,
as in Figure 1 or at the head of each branch line, as in Figure 2 or at
each location where fuel-gas is withdrawn, as in Figure 3. Where branch
lines are of 2-inch pipe size or larger or of substantial length, protective
equipment (designated as PF) shall be located as shown in either 2 or
3.
(4) Backflow protection must be provided by an approved device that will
prevent oxygen from flowing into the fuel-gas system or fuel from flowing
into the oxygen system (see SF, Figs. 1 and 2).
(5) Flash-back protection must be provided by an approved device that
will prevent flame from passing into the fuel-gas system.
(6) Back-pressure protection must be provided by an approved pressure-relief
device set at a pressure not greater than the pressure rating of the backflow
or the flashback protection device, whichever is lower. The pressure-relief
device must be located on the downstream side of the backflow and flashback
protection devices. The vent from the pressure-relief device must be at
least as large as the relief device inlet and must be installed without
low points that may collect moisture. If low points are unavoidable, drip
pots with drains closed with screw plugs or caps shall be installed at
the low points. The vent terminus must not endanger personnel or property
through gas discharge; must be located away from ignition sources; and
must terminate in a hood or bend.
(7) If pipeline protective equipment incorporates a liquid, the liquid
level must be maintained, and a suitable antifreeze may be used to prevent
freezing.
(8) Fuel-gas for use with equipment not requiring oxygen must be withdrawn
upstream of the piping protective devices.
WAC 296-307-48049
What requirements apply to station outlet protective equipment?
(1) A check valve pressure regulator, hydraulic seal, or combination
of these devices must be provided at each station outlet, including those
on portable headers, to prevent backflow, as shown in Figures 1, 2, and
3 and designated as SF and SO.
(2) When approved pipeline protective equipment (designated PF) is located
at the station outlet as in Figure 3, no additional check valve, pressure
regulator, or hydraulic seal is required.
(3) Each station outlet must have a shut-off valve (designated VF and
VO) installed on the upstream side of other station outlet equipment.
(4) If the station outlet is equipped with a detachable regulator, the
outlet must terminate in a union connection that meets the requirements
of the Regulator Connection Standards, 1958, Compressed Gas Association.
(5) If the station outlet is connected directly to a hose, the outlet
must terminate in a union connection that meets the requirements of the
Standard Hose Connection Specifications, 1957, Compressed Gas Association.
(6) Station outlets may terminate in pipe threads to which permanent
connections are to be made, such as to a machine.
(7) Station outlets must have a detachable outlet seal cap secured in
place. This cap must be used to seal the outlet except when a hose, a
regulator, or piping is attached.
(8) Where station outlets are equipped with approved backflow and flashback
protective devices, as many as four torches may be supplied from one station
outlet through rigid piping, if each outlet from such piping, is equipped
with a shut-off valve and if the fuel-gas capacity of any one torch does
not exceed 15 cubic feet per hour. This rule does not apply to machines.
WAC 296-307-48051
What requirements apply to hose and hose connections?
(1) Hose for oxy-fuel gas service must meet the requirements of the Specification
for Rubber Welding Hose, 1958, Compressed Gas Association and Rubber Manufacturers
Association.
(2) The generally recognized colors are red for acetylene and other fuel-gas
hose, green for oxygen hose, and black for inert-gas and air hose.
(3) When parallel lengths of oxygen and acetylene hose are taped together
for convenience and to prevent tangling, a maximum of 4 inches out of
12 inches must be covered by tape.
(4) Hose connections must meet the requirements of the Standard Hose
Connection Specifications, 1957, Compressed Gas Association.
(5) Hose connections must be clamped or otherwise securely fastened so
they will withstand, without leakage, twice the pressure to which they
are normally subjected in service, but never less than a pressure of 300
psi. Oil-free air or an oil-free inert gas must be used for the test.
(6) Hose showing leaks, burns, worn places, or other defects rendering
it unfit for service must be repaired or replaced.
WAC 296-307-48053
What requirements apply to pressure-reducing regulators?
(1) Pressure-reducing regulators must be used only for the gas and pressures
for which they are intended. The regulator inlet connections must meet
the requirements of the Regulator Connection Standards, 1958, Compressed
Gas Association.
(2) When regulators or parts of regulators, including gauges, need repair,
the work must be performed by skilled mechanics who have been properly
instructed.
(3) Gauges on oxygen regulators must be marked “use no oil.”
(4) Union nuts and connections on regulators must be inspected before
use to detect faulty seats that may cause leakage of gas when the regulators
are attached to the cylinder valves. Damaged nuts or connections must
be destroyed.
WAC 296-307-48501
What general requirements apply to resistance welding equipment?
(1) All equipment must be installed by a qualified electrician according
to the requirements of chapter 296-307
WAC Part T. There must be a safety-type disconnecting switch
or a circuit breaker or circuit interrupter to open each power
circuit to the machine, conveniently located at or near the machine,
so that the power can be shut off when the machine or its controls
are to be serviced.
(2) Ignitron tubes used in resistance welding equipment must have a thermal
protection switch.
(3) Employees designated to operate resistance welding equipment must
have been properly instructed and judged competent to operate such equipment.
(4) Controls of all automatic or air and hydraulic clamps must be arranged
or guarded to prevent the operator from accidentally activating them.
WAC 296-307-48503
What requirements apply to portable welding machines?
(1) All portable welding guns must have suitable counter-balanced devices
for supporting the guns, including cables, unless the design of the gun
or fixture makes counterbalancing impractical or unnecessary.
(2) All portable welding guns, transformers, and related equipment that
is suspended from overhead structures, eye beams, or trolleys must have
safety chains or cables. Safety chains or cables shall be able to support
the total shock load in the event of failure of any component of the supporting
system.
(3) When trolleys are used to support portable welding equipment, they
must have suitable forged steel clevis for the attachment of safety chains.
Each clevis must be able to support the total shock load of the suspended
equipment in the event of trolley failure.
(4) All initiating switches, including retraction and dual schedule switches,
located on the portable welding gun must have suitable guards able to
prevent accidental initiation through contact with fixturing, operator's
clothing, etc. Initiating switch voltage must be a maximum of 24 volts.
(5) The movable holder, where it enters the gun frame, must have enough
clearance to prevent the shearing an operator's fingers if placed on the
operating movable holder.
(6) The secondary and case of all portable welding transformers must
be grounded. Secondary grounding may be by center tapped secondary or
by a center tapped grounding reactor connected across the secondary.
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