Mechanical
Instructions
Site
Selection
Review
the
NEMA
Type
rating
of
the
heater
noted
on
the
HEATREX
Application
Data.
Do
not
install
a
heater
in
an
area
not
consistent
with
its
rating.
Allow
sufficient
free
space
around
heater
installation
site.
Work
space
for
heater
maintenance
should
be
at
least
three
feet
in
front
and
on
either
side
of
the
heater.
The
minimum
pull
space
for
the
heating
element
installation
or
removal
from
the
pipe/tube
should
be
at
least
four
feet.
The
heating
element
is
designed
to
be
flexible
and
can
be
curved
if
necessary.
Electric
heaters
are
capable
of
developing
high
temperatures.
Therefore,
extreme
care
should
be
taken
to
avoid
mounting
heaters
in
an
atmosphere
containing
combustible
gases,
vapors,
dusts,
or
fibers
unless
properly
marked
as
suitable
for
the
condition.
Heater
Orientation
This
style
of
heater
is
intended
for
horizontal
use
only.
The
open
coil
resistance
wire
must
not
be
mounted
in
a
vertical
orientation
or
failure
could
occur
from
the
coil
sagging.
The
heater
must
be
mounted
plumb
horizontally
to
assure
proper
operation.
Thermal
expansion
of
the
heater
pipes
must
be
considered
when
locating
the
heater.
It
can
be
approximated
as:
Pipe
Length
(Inches)
x
.00001
x
Max
Pipe
Operating
Temp
(
°
F)
‐
70
°
F
2
If
the
heater
is
installed
in
a
pressurized
tank,
a
relief
valve
must
be
installed.
As
a
minimum,
the
valve
must
be
sized
to
relieve
at
a
rate
equal
to
the
rate
that
the
heater
can
thermally
expand
fluid
in
the
tank.
Pipe
Installation
On
heater
pipes
provided
with
ANSI
flanged
connections,
take
care
to
prevent
scratching
the
flange
faces.
HEATREX
supplies
a
non
‐
asbestos
nitrile
bonded
fiber
flange
gasket
unless
otherwise
requested.
The
user
must
confirm
that
the
gasket
is
suitable
for
the
application.
The
user
must
supply
high
strength
studs
or
bolts
and
nuts,
such
as
A
‐
193
GR.
B7
and
A194
GR.
2H,
rated
for
the
design
conditions.
Bolts
must
be
properly
installed
and
tightened
to
prevent
leaks.
When
heater
pipes
are
welded
directly
to
the
user’s
tank
wall,
remove
the
heating
element
from
the
pipe
before
welding.
Refer
to
the
following
instructions
for
handling
and
removing
heating
elements.
Heater
pipes
must
be
supported
inside
the
user’s
tank.
Supports
must
not
prevent
the
pipes
from
thermally
expanding.
Supports
should
be
located
on
a
maximum
spacing
of
10
feet.
Where
buildup
of
solids
in
the
bottom
of
the
tank
is
expected,
the
pipe
must
be
located
above
that
level.
The
pipe
must
also
be
located
below
the
minimum
operating
fluid
level
of
the
tank.
Heater
pipes
must
be
perfectly
clean
before
installation
of
heating
element.
Use
only
a
clean
dry
cloth
to
clean.
Never
use
a
lubricant.
Compressed
air
with
a
long
wand
may
be
used
to
remove
ceramic
chips,
etc.
If
the
heater
pipe
is
not
supplied
by
HEATREX,
ensure
the
pipe
length
is
correct
by
measuring
the
heating
element
overall
length
(OAL),
the
cold
length
from
the
start
of
the
coiled
wire
to
the
front
end
of
the
heating
element
(CL),
and
the
length
of
the
heater
pipe
not
including
the
pipe
cap
(PL).
The
pipe
length
PL
must
be
greater
than
or
equal
to
OAL.
When
locating
the
heater
pipe
in
the
tank,
the
distance
from
the
front
end
of
the
pipe
to
the
exterior
tank
wall
must
be
less
than
or
equal
to
CL
to
ensure
the
heated
area
is
in
the
fluid.
Heating
Element
Installation
&
Removal
To
remove
the
heating
element
from
a
heater
pipe
or
shipping
tube,
first
remove
the
fastening
nut
at
the
terminal
end.
Hold
the
ceramic
insulator
firmly
in
order
to
avoid
undue
pressure
on
the
ceramic
and
possible
breakage.
If
obstructions
are
encountered,
rotate
the
heater
slightly
back
and
forth
while
pulling
out.
Since
heating
elements
can
be
of
considerable
length,
it
may
not
always
be
possible
to
remove
the
element
in
a
straight
line,
due
to
space
limitations.
Since
the
element
bar
is
flexible,
the
element
may
be
curved
on
a
radius
of
4
feet
minimum.
It
is
recommended
that
at
least
2
people
be
used
for
this
procedure,
in
order
to
avoid
breaking
the
ceramics.
After
the
element
bar
has
been
removed,
it
should
be
carefully
stretched
out
on
a
clean
table
for
inspection.
Broken
ceramics
must
be
replaced
and
burn
spots
should
be
cleaned
with
a
dry
clean
paper
or
cloth
towel.
Oil
or
other
contamination
on
the
heater
will
cause
a
failure.
When
installing
the
heating
element
into
the
heater
pipe,
reverse
the
steps
noted
above.
Heater
pipes
must
be
perfectly
clean
before
installation
of
element.
Use
only
a
clean
dry
cloth
to
clean.
Never
use
a
lubricant.
Compressed
air
with
a
long
wand
may
be
used
to
remove
ceramic
chips,
etc.
The
heating
element
intended
only
to
be
installed
with
the
sheet
metal
strip
on
the
bottom.
Do
not
rotate
the
heater
in
the
pipe.
CAUTION -Hazard of Electric Shock
Heaters
must
be
bolted
into
position
at
the
terminal
end
to
prevent
movement,
which
could
allow
the
heater
to
short
out
against
the
pipe.
See
figures
attached
for
mounting
configurations.
Thermal
insulation
must
be
installed
between
the
first
few
ceramics
in
the
“cold”
section
of
the
heater
where
the
resistance
wire
is
not
coiled.
A
loose
fill
cerafiber
(HEATREX
P/N
1008466)
or
equal,
rated
for
2000
°
F,
is
preferred.
The
insulation
must
be
free
of
moisture
or
contamination
in
order
to
provide
electrical
isolation.
The
insulation
is
necessary
to
allow
90
°
C
rated
field
wiring.