Miller AUTO ARC MW 4150 User manual

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MILLER
ELECTRIC MFG.
CO.
718
S.
BOUNDS
ST.
P.O.
Box
1079
APPLETON,
WI
54912
USA
ADDITIONAL
COPY
PRICE
$145
IMPORTANT
June
1989
Read
and
understand
the
entire
contents
of
this
manual,
with
special emphasis
on
the
safety
material
throughout
the
manual,
before
installing,
operating,
or
maintaining
this
equip
ment.
This
unit
and
these
instructions
are
for
use
only
by
persons
trained
and
experienced
in
the
safe
operation
of
welding
equipment.
Do
not
allow
un
trained
persons
to
install,
operate,
or maintain this
unit.
Contact
your
distributor
if
you
do
not
fully
understand
these instructions.
FORM:
113
336B
Effective
With
Serial
No.
JK585798
MODEL
AUTO
ARC
MW
4150
sPW1
OWN
ERS
MANUAL
NWSA
CODE
NO. 4579
PRINTED
IN
U.S.A.

THIS WARRANTY IS OFFERED
IN
LIEU OF ANY OTHER
EXPRESS
WARRANTY;
AND,
EXCEPT
TO THE EXTENT
PROHIBITED
BY
APPLICABLE
LAW,
THE DURATION
OF
ALL IMPLIED
WARRANTIES,
INCLUDING BUT NOT
LIMITED TO THE IMPLIED WARRANTIES OF MERCI-IAN
TABILITYAND FITNESS FOR
A
PARTICULAR
PURPOSE,
IS
LIMITED TO THE
DURATION OF THIS WARRANTY.
Some
states
do
not
allow limitations
on
how
long
an
implied
warranty
lasts,
so
the above
limitation
may
not
apply
to
you.
This
warranty
gives
you
specific legal
rights,
and
you
may
also
have other
rights
which
vary
from
state
to state.
Except
as
specified
below,
Millers
warranty
does not
apply
to
components having
normal useful life of less than
one
(1)
year,
such
as
spot
welder
tips,
relay
and
contactor
points,
parts
that
come
in
contact with the
welding
wire
including
nozzles and
nozzle insulators
where
failure does
not
result from defect in
workmanship
or
material.
Miller shall
be
required
to
honorwarranty
claims
on
warranted
Equipment
in the
event
of
failure
resulting
from
a
defect
within
the
following
periods
from the
date of
delivery
of
Equipment
to
the
original
user:
1.
Arc
welders,
power
sources,
and
components ...
1
year
2.
Original
main
power
rectifiers
3
years
(labor

1
year
only)
3.
All
welding
guns,
feeder/guns
and
torches
90
days
4.
Replacement
or
repair
parts,
exclusive
of labor
60
days
WHAT IS
NOT
COVERED

This
warranty
does
not
extend
to
any
Welder
subjected
to
misuse,
neglect,
accident,
or
in-
warranty
repair by
anyone
except
Miller Electric.
Further,
this
warranty
only
extends
to
those
purchasing
the Welder
for
per
sonal,
family
or
household
purposes.
Commercial
and
indus
trial
users
are
given
a
different
warranty.
THE PURCHASERS
REMEDIES FOR
A
DEFECTIVE
WELDER,
TO THE
EXTENT PERMITTED
BY
APPLICABLE
LAW,
ARE
LIMITED
TO THE REMEDY PROVIDED BY THIS
WARRANTY:
AND,
TO
THE EXTENT ENFORCEABLE
UNDER APPLICABLE
LAW,
MILLER ELECTRIC SHALL
IN
NO
EVENT BE LIABLE
FOR
CONSEQUENTIAL,
INCIDEN
TAL OR SPECIAL
DAMAGES
ARISING OUT
OF
THE USE
OF,
OR INABILITY TO
USE,
THE
WELDER,
WHETHER
BASED
ON
BREACH
OF
THIS
WARRANTY,
MILLER
ELECTRICS NEGLIGENCE OR OTHER
TORT,
OR ON ANY
THEORY
OF STRICT
LIABILITY.
Some
states
do
not
allow the
exclusion
or
limitation
of
conse
quential
or
incidental
damages,
so
the
above
limitations
may
not
apply
to
you.
PROCEDURE FOR
OBTAINING
WARRANTY
PERFORM
ANCE
As
soon
as
any
defect
in
a
Welder becomes
known,
the
pur
chaser
of
the Welder
must,
within
thirty
(30)
days,
notify
an
approved Warranty
Station
or
Miller
Electric in
writing
of the
defect. The
purchaser
must
then,
within
the
one
year warranty
period,
return the
Welder
to
Miller
Electric
at
the
following
ad
dress:
Miller Electric
Mfg.
Co.
1635
W.
Spencer
St.
P.O.
Box
1079
Appleton,
Wisconsin
54912
ONE
YEAR
LIMITED WARRANTY
COVERAGE

Miller
Electric
Mfg.
Co.
warrants
to the
buyer
REMEDY FOR DEFECTIVE
WELDERUpon
receipt
of
any
who
purchases
this
Auto Arc Welder
(Welder)
for
personal,
defective
Welder,
Miller Electric
will,
at
its
option,
repair
or
re
familyorhouseholdpurposes(Consumer)thatthisWelderwill
place
the
defective
Welderat
its
expense,
refund
orcredit
the
be
free
from
defects in material
andworkmanship
fora
period
of
purchase
price
(less
reasonable
depreciation
based
on
actual
one
year from
the date of
purchase.
This
warranty
covers
only
use),
or
reimburse the Consumer
for the
cost
of
repair
or
re
the
original purchaser
of this Welder. Miller
Electric
does
not
placement
atan
approved
Miller Electric
warranty
station,
pro-
authorize
any
party,
including
its
authorized
distributors,
to
offer
vided that
the
purchaser
of
that
Welder
has
followed
the
proce
any
other
warranty
on
behalf
of
Miller Electric.
Upon
expiration
dure
for
obtaining
warranty
performance
set
forth below.
The
of the
warranty
period,
Miller
Electric shall have
no
further liabil-
Welder
so
repaired
or
used
as
a
replacementwill
be
shipped
to
ityrelatedtothoWelder,exceptonwarrantyclaimsmadeduring
the
purchaser
of the defective
Welder,
with
transportation
the
warranty
period, charges prepaid
to
any
destination
in
the
continental United
States
(transportation charges
on
shipments
to Alaska
or
Hawaii
will be
paid
only
to
the
nearest
port
of
export).
All
transportation
charges
to
Warranty
Station
or
Miller
L
Electric
must be
prepaid.

ERRATA
SHEET
AMENDMENT
TO
SECTION 11

PARTS
LIST
Amend
Parts
List
as
follows:
After
this
manual
was
printed,
refinements
in
equipment
design
occurred. This
sheet
lists
exceptions
to
data
appearing
later
In
this
manual.
AMENDMENT
TO SECTION
4-
INSTALLATION
Amend
Step
4
of
Section
4-3.
RUNNING
GEAR
INSTALLATION
4.
Secure
wheels
in
place
with
supplied
retaining rings.
Amend
Figure
4-2.
Running
Gear
Installation
Cap
Screw
Cylinder
Bracket
Two
Front
Screw
Nut
Rack
Spreader
Bar
Cap
Screw
Casters
Nut
Wheel
Retaining
Ring
Figure
42.
Running
Gear
installatIon
**
Part
No.
Replaced
With
TC.049
808-E
Quantity Description
50-11 032 524
121
614
RING,
retaining
ext
.750
shaft
x
.082
(Effw/KA775591)
50-13 052
692
135
390
AXLE,
running
gear
(Eft w/KA775591)
**First
digit
represents
page
no
-
digits following
dash
represent
item
no.
BE
SURE
TO PROVIDE
MODEL AND
SERIAL
NUMBER
WHEN
ORDERING
REPLACEMENT
PARTS.
2
I

RECEIVING-HANDLING
Before
unpacking
equipment,
check
carton
forany
dam-
Use
the
following
spaces
to
record the
Model
Designa
age
that
may
have
occurred
during
shipment.
File
any
tion and
Serial
or
Style
Number
of
your
unit.
The
infor
claims
for loss
or
damage
with the
deliverIng
carrier.
mation
is
located
on
the
data
card
or
the
nameplate.
Assistance
for
filing
or
settling
claims
may
be
obtained
from
the distributor
and/or the
equipment
manufactur-
Model
________________________________________
ers
Transportation
Department.
Serial
or
Style
No._____________________________
When
requesting
information
about this
equipment,
al
ways
provide
the Model
Description
and
Serial
or
Style
Date
of Purchase
______________________________
Number.
TABLE
OF
CONTENTS
Section
No.
Page
No.
SECTION
1

SAFETY
RULES FOR OPERATION
OF ARC WELDING POWER SOURCE
1-1.
Introduction
1
1-2.
General
Precautions 1
1-3.
Arc
Welding
3
1-4.
Standards
Booklet
Index
5
SECTION
2-
SAFETY
PRECAUTIONS
AND
SIGNAL
WORDS
2-1.
General
Information
And
Safety
6
2-2.
Safety
Alert
Symbol
And
Signal
Words
..
6
SECTION
3
INTRODUCTION
3-1.
Volt-Ampere
Curves
8
3-2.
Duty
Cycle
8
3-3.
Description
8
3-4.
Supplied
Equipment
8
3-5.
Additional
Required
Equipment
9
3-6.
Optional
Equipment 10
3-7.
Consumable
Parts
10
SECTION
4
INSTALLATION
4-1.
Site Selection
10
4-2.
Transporting
Methods
10
4-3.
Running
Gear
Installation
11
4-4.
Optional
SPW-1
Panel
Installation
11
4-5.
Shielding
Gas
Installation
12
4-6.
Work Cable
Assembly
13
4-7.
Weld
Polarity
Selection
14
4-8.
MWG-200
Welding
Gun
Connections
14
4-9.
Installation
Of
Optional
Spool
Gun
15
4-10.
Welding
Wire
Spool
Installation
16
4-11.
Hub
Tension
Adjustment
16
4-12.
Electrical
Input
Connections
16
4-13.
Welding
Wire
Threading
17

Section
No.
Page
No.
SECTION
5
OPERATOR
CONTROLS
5-1.
Power Switch And
Pilot
Light
19
5-2.
ThicknessNolts Selector
19
5-3. Fine
Tuning/Wire
Speed
Control
19
5-4.
Fan-On-Demand
19
5-5.
Optional Spot
Pulse Panel
Controls
19
SECTION
6
SEQUENCE OF OPERATION
6-1.
Gas
Metal Arc
Welding (GMAW)-Continuous
And
Gas
Metal Arc
Welding-Pulsed
Arc
(GMAW-P)
20
6-2.
Gas
Metal Arc
Welding
(GMAW)-Spot
(Models
With
Optional
SPW-1
Panel
Only)
22
6-3
Shutting
Down 23
SECTION
7-
MAINTENANCE
&
TROUBLESHOOTING
7-1.
Routine Maintenance
23
7-2.
Replacing
Drive
Roll And
Wire Inlet Guide
24
7-3. Drive
Housing
Realignment
26
7-4.
Replacing
Hub
Assembly
26
7-5.
Inspecting
And
Replacing
Motor Brushes
26
7-6.
Overload
Protection 27
7-7.
Thermal
Overload Protection
27
7-8. Printed Circuit
Board
Replacement
27
7-9.
Troubleshooting
27
SECTION
8-
ELECTRICAL
DIAGRAMS
Diagram
8-1.
Circuit
Diagram
30
Diagram
8-2.
Circuit
Diagram
For
SPW-1
Panel
30
SECTION
9
WELDING
TECHNIQUES
&
TROUBLESHOOTING
9-1.
Gas
Metal
Arc
Welding (GMAW)Continuous
Seam
31
9-2.
Gas
Metal
Arc
Welding
(GMAW)-Pulsed
32
9-3.
Gas
Metal Arc
Welding (GMAW)-Spot
33
9-4.
Plug
Welds
34
9-5.
Skip
Welding
34
9-6.
Troubleshooting
The
Gas
Metal Arc
Welding
Process
34
SECTION
10
AUTO BODY
REPAIR
APPLICATION
10-1.
Pointers
For
Welding
Auto
Body
Sheet
Metal
37
10-2.
Procedure
For
Welding
Mild
Steels
37
10-3.
Procedures
For
Welding
Door
Panels
37
10-4.
How
To
Prevent
Glass
Breakage
And
Spatter
On
Windows
38
10-5.
Procedures
For
Welding
Fenders
And
Quarter
Panels
38
10-6.
Welding
Frames
And
High
Strength
(HSS)
Steels
38

Section
No.
Page
No.
SECTION
11

PARTS
LIST
Figure
11-1.
Main
Assembly
40
Figure
11-2.
Baffle,
Air
-
W/Components
42
Figure
11-3.
Drive
Assembly,
Wire
44
Figure
11-4.
Panel,
Rear
-
W/Components
45
Figure
11-5.
Panel,
Front
-
W/Components
46
Figure
11-6.
SPW
1
Spot
Panel
(Optional)
48
Figure
11-7.
Circuit
Card,
PC5O
49
Figure
11-8.
Running
Gear
50
LIST OF CHARTS
AND
TABLES
Table
3-1.
Specifications
7
Chart
3-1.
Volt-Ampere
Curves
7
Chart
3-2.
Duty
Cycle
7
Table
3-2.
Input
Conductor
And Fuse
Size
17
Table
6-1.
Suggested
Parameters For
Continuous Gas
Metal
Arc
Welding
(GMAW)
21
Table
6-2.
Checking
Weld
Parameters
23
Table
7-1.
Maintenance Schedule
23
Table
7-2.
Troubleshooting
28

SECTION
1

SAFETY
RULES
FOR
OPERATION
OF
ARC
WELDING POWER
SOURCE
1-1.
INTRODUCTION
We learn
by
experience.
Learning safety through
per
sonal
experience,
like
a
child
touching
a
hot
stove
is
harmful, wasteful,
and unwise. Let the
experience
of
oth
ers
teach
you.
Safe
practices
developed
from
experience
in
the
use
of
welding
and
cutting
are
described
in
this
manual. Re
search,
development,
and
field
experience
have
evolved reliable
equipment
and safe
installation,
opera
tion,
and
servicing practices.
Accidents
occur
when
equipment
is
improperly
used
or
maintained. The
rea
son
for the
safe
practices
may
not
always
be
given.
Some
are
based
on common
sense,
others
may
require
technical volumes
to
explain.
It is wiser
to
follow the
rules.
Read and understand these safe
practices
before
at
tempting
to
install,
operate,
or
service the
equipment.
Comply
with these
procedures
as
applicable
to
the
par
ticular
equipment
used and theirinstruction
manuals,
for
personal safety
and for the
safety
of others.
Failure
to
observe these safe
practices
may
cause
seri
ous
injury
or
death. When
safety
becomes
a
habit,
the
equipment
can
be used with confidence.
These
safe
practices
are
divided into
two
Sections:
1-General
Precautions,
common
to
arc
welding
and
cut
ting;
and 2-Arc
Welding
(and
Cutting)
(only).
Reference
standards:
Published
Standards
on
safety
are
also
available
for
additional and
more
complete
pro
cedures than
those
given
in
this manual.
They
are
listed
in
the
Standards
Index
in
this manual.
ANSI
Z49.
1
is
the
most
complete.
The
National Electrical
Code,
Occupational
Safety
and
Health
Administration,
local
industrial
codes,
and
local
inspection
requirements
also
provide
a
basis for
equip
ment
installation,
use,
and
service.
1-2.
GENERAL
PRECAUTIONS
Different
arc
welding
processes,
electrode
alloys,
and fluxes
can
produce
different
fumes,
gases,
and
radiation
levels.
In
addition
to
the
Information
In
this
manual,
be
sure
to
consult
flux and
electrode
manu
facturers
MaterIal
Safety
Data
Sheets
(MSDSs)
for
specIfic
technical data
and
precautionary
measures
concerning
their
material.
A.
Burn
Prevention
Wear
protective
clothing-gauntlet
gloves
designed
for
use
in
welding,
hat,
and
high
safety-toe
shoes.
Button
shirt
collar
and
pocket
flaps,
and
wear
cuffless
trousers
to
avoid
entry
of
sparks
and
slag.
Wear
helmet
with
safety
goggles
and
glasses
with
side
shields
underneath,
appropriate
filter
lenses
or
plates
(protected
by
clear cover
glass).
This
is
a
MUST
for
welding
or
cutting,
(and chipping)
to
protect
the
eyes
from radiant
energy
and
flying
metal.
Replace
cover
glass
when
broken,
pitted,
or
spattered.
See
1-3A.2.
Avoid
oily
or
greasy
clothing.
A
spark
may
Ignite
them.
Hot
metal such
as
electrode stubs
and
workpleces
should
never
be handled without
gloves.
Medical first aid
and
eye
treatment.
First aid facilities
and
a
qualified
first
aid
person
should be
available
for each
shift unless medical facilities
are
close
by
for
immediate
treatment
of flash burns of the
eyes
and skin burns.
Ear
plugs
should be
worn
when
working
on
overhead
or,
in
a
confined
space.
A
hard hat should be
worn
when
others
work overhead.
Flammable
hair
preparations
should
not
be used
by
per
sons
intending
to
weld
or
cut.
B.
Toxic
Fume Prevention
Severe
discomfort,
illness
or
death
can
result from
fumes,
vapors,
heat,
or
oxygen
enrichment
or
depletion
that
welding (orcutting)
may
produce.
Prevent them with
adequate
ventilation
as
described
in
ANSI Standard
Z49.1 listed
in
Standards Index.
NEVER
ventilate with
oxygen.
Lead
-,cadmium-, zinc-,
mercury-,
and
beryllium-bear
ing
and similar
materials,
when
welded
(or cut)
may pro
duce harmful
concentrations of toxic fumes.
Adequate
local exhaust ventilation
must
be
used,
or
each
person
in
the
area as
well
as
the
operator
must
wear an
air-sup
plied respirator.
For
beryllium,
both
must
be
used.
Metals coated with
orcontaining
materials that
emittoxic
fumes
should
not
be heated
unless
coating
is
removed
from the work
surface,
the
area
is well
ventilated
and,
if
necessary,
while
wearing
an
air-supplied
respirator.
Work
in
a
confined
space
onlywhile
it is
being
ventilated
and,
if
necessary,
while
wearing
an
air-supplied
respira
tor.
Gas
leaks
in
a
confined
space
should
be
avoided.
Leaked
gas
in
large
quantities
can
change
oxygen
con
centration
dangerously.
Do
not
bring
gas
cylinders
into
a
confined
space.
Leaving
confined
space,
shut
OFF
gas
supply
at
source
to
prevent
possible
accumulation
of
gases
in
the
space
if
downstream
valves
have been
accidentally
opened
or
left
open.
Check
to
be
sure
that
the
space
is
safe
before
re-entering
it.
Vapors
from
chlorinated
solvents
can
be
decomposed
by
the heat
of the
arc
(or
flame)
to
form
PHOSGENE,
a
highly
toxic
gas,
and other
lung
and
eye
irritating
prod
ucts.
The
ultraviolet
(radiant)
energy
of
the
arc
can
also
decompose
trichloroethylene
and
perchloroethylene
vapors
to
form
phosgene.
DO
NOT
WELD
or cut
where
solvent
vapors
can
be
drawn
into
the
welding
or
cutting
atmosphere
or where
the
radiant
energy
can
penetrate
113336
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1

to
atmospheres
containing
even
minute
amounts
of
trichloroethylene
or
perchloroethylene.
C.
Fire
and
Explosion
Prevention
Causes
of
fire and
explosion
are:
combustibles
reached
bythe
arc,
flame,
flying
sparks,
hot
slag
or
heated
mate
rial;
misuse
of
compressed
gases
and
cylinders;
and
short
circuits.
BE
AWARE THAT
flying sparks
or
falling
slag
can
pass
through
cracks,
along pipes, through
windows
or
doors,
and
through
wall
or
floor
openings,
out
of
sight
of
the
goggled
operator.
Sparks
and
slag
can
fly
35 feet.
To
prevent
fires
and
explosion:
Keep
equipment
clean
and
operable,
free
of
oil,
grease,
and
(in
electrical
parts)
of
metallic
particles
that
can
cause
short circuits.
If
combustibles
are
in
area,
do
NOT
weld
or
cut.
Move
the
work
if
practicable,
to
an
area
free
of
combustibles.
Avoid
pai
nt
spray
rooms,
dip
tanks,
storage
areas,
venti
lators.
If
the work
cannot
be
moved,
move
combustibles
at
least
35
feet
away
out
of
reach
of
sparks
and
heat;
or
protect
against
ignition
with
suitable
and
snug-fitting,
fire-resistant
covers or
shields.
Walls
touching
combustibles
on
opposite
sides
should
not
be
welded
on
(or cut).
Walls,
ceilings,
and floor
near
work
should
be
protected by
heat-resistant
covers or
shields.
Fire
watcher
must
be
standing
by
with
suitable
fire
extin
guishing
equipment
during
and for
some
time
afterweld
ing
or
cutting
if:
a.
appreciable
combustibles
(including
building
construction)
are
within 35
feet
b.
appreciable
combustibles
are
further
than
35
feet
but
can
be
ignited
by sparks
c.
openings
(concealed
orvisible)
in
floors
orwalls
within
35
feet
may expose
combustibles
to
sparks
d.
combustibles
adjacent
to
walls,
ceilings,
roofs,
or
metal
partitions
can
be
ignited
by
radiant
or
conducted
heat.
Hot
work
permit
should
be
obtained
before
operation
to
ensure
supervisors
approvalthat
adequate
precautions
have
been
taken.
After
work
is
done,
check
that
area
is
free
of
sparks,
glowing
embers,
and
flames.
An
empty
container
that
held
combustibles,
or
that
can
produce
flammable
or
toxic
vapors
when
heated,
must
never
be
welded
on or
cut,
unless container
has
first
been
cleaned
as
described
in
AWS
Standard
A6.O,
listed
7
in
Standards
Index.
This
includes:
a
thorough
steam
orcaustic
cleaning
(or
a
solvent
or
water
washing,
depending
on
the
combusti
bles
solubility)
followed
by
purging
and
inerting
with
ni
trogen
or
carbon
dioxide,
and
using
protective
equip-
ment
as
recommended
in
A6.O.
Waterfilling just
below
working
level
may
substitute for
inerting.
A
container
with
unknown
contents
should be cleaned
(see
preceding
paragraph).
Do
NOT
depend
on
sense
of
smell
or
sight
to
determine
if
it is safe
to
weld
or
cut.
Hollow
castings
or
containers
must
be vented
before
welding
or
cutting.
They
can
explode.
Explosive atmospheres.
Neverweld
orcut
where
the air
may
contain flammable
dust,
gas,
or
liquid
vapors
(such
as
gasoline).
D.
Compressed
Gas
Equipment
Standard
precautions.
Comply
with
precautions
in
this
manual,
andthose
detailed
in
CGA
Standard
P-1,SAFE
HANDLING
OF
COMPRESSED
GASES
IN
CYLIN
DERS,
listed
11
in
Standards
Index.
1.
Pressure
Regulators
Regulator
relief
valve
is
designed
to
protect
only
the
regulator
from
overpressure;
it
is
not
intended
to
protect
any
downstream
equipment.
Provide
such
protection
with
one
or
more
relief
devices.
Never
connect
a
regulator
to
a
cylinder
containing
gas
other
than
that
for which
the
regulator
was
designed.
Remove
faulty
regulatorfrom
service
immediatelyfor
re
pair
(first
close
cylinder
valve).
The
following
symptoms
indicate
a
faulty regulator:
Leaks-if
gas
leaks
externally.
Excessive
Creep-if
delivery
pressure
continues
to
rise
with
downstream
valve
closed.
Faulty
Gauge-if
gauge
pointer
does
not
move
off
stop
pin
when
pressurized,
nor
returns
to
stop
pin
after
pressure
release.
Repair.
Do NOT
attempt
to
repair.
Send
faulty
regulators
for
repair
to
manufacturers
designated
repair center,
where
special
techniques
and tools
are
used
by
trained
personnel.
2.
Cylinders
Cylinders
must
be
handled
carefully
to
prevent
leaks
and
damage
to
their
walls,
valves,
or
safety
devices:
Avoid
electrical circuit
contact
with
cylinders
including
third
rails,
electrical
wires,
or
welding
circuits.
They
can
produce
short circuit
arcs
that
may
lead
to
a
serious
acci
dent.
(See
1-3C.)
ICC
or
DOT
marking
must
be
on
each
cylinder.
It
is
an
assurance
of
safety
when
the
cylinder
is
properly
han
dled.
Identifying
gas
content.
Use
only
cylinders
with
name
of
gas
marked
on
them;
do
not
rely
on
color
to
identify
gas
content.
Notify supplier
if
unmarked.
NEVER
DEFACE
or
alter
name,
number,
or
other
markings
on
a
cylinder.
It
is
illegal
and
hazardous.
Empties:
Keep
valves
closed,
replace
caps
securely;
mark
MT;
keep
them
separate
from
FULLS
and
return
promptly.
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336
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