COMPONENT - Tubular Heaters
Tubular Heater Design & Installation Guidelines
Design Considerations
Sheath Material
For resisting corrosion inherent in the process or environment and for withstanding
the sheath temperature required. Standard sheath materials are INCOLOY ®,
steel, copper and stainless steel (type 304). Other types of stainless steel, MONEL®,
titanium and INCONEL are available.
Job Requirements
The calculation of total heat requirements for an application is outlined in Technical
section. For assistance, contact your Local Chromalox field sales engineer who will
be glad to contribute his judgement, experience and knowledge in solv ing your heating
problem.
After the specific heater size and rating has been tentatively selected, the watt
density must be checked against the curves in Technical section.
If the heater selected has a watt density higher than stipulated by the curve, consider
these alternatives:
- Use more heaters of a lower watt density to obtain the required
kW capacity.
- Reduce the kW capacity needed by reducing heat losses and/or allowing
for a longer heat-up time.
Watt Densities
The watt density of the element, or watts per square inch of element heated area,
should be low for heating asphalt, molasses and other thick substances with low
heat transferability. It can be higher for heating air, metals, liquids and other
heat-conducting materials. See curves in Technical section for determining allowable
watt densities.
When high operating temperatures are needed, watt density must be limited in order
not to exceed the maximum sheath tempera ture. Watt density is given in the specifications
for each tubular heater.
In general, a viscous material with low thermal conductivity requires a low watt
density. Higher watt densities can be used with thinner liquids and with materials
of high thermal conductivity. Premature loss of the element due to excessive temperature
may result if the material’s heat-take-away ability is low. Also, the material may
be charred, carbonized or its chemical makeup altered by overheating.
Terminal Selection
Stocked tubulars are shipped with standard terminals, see Terminal Options in this
section. Many other terminals and terminal end seals are available made to order.
CAUTION
Protect terminals from possible contamination from surrounding atmospheres such
as oil fumes, chemical vapors from other processes, moisture, weather, etc. MgO
insulation is hygroscopic.
Vacuums
Tubular heaters operate at higher temperatures in a vacuum because there is no air
to take away the heat. Therefore, watt densities are recommended to be 20 to 30%
lower. It is recommended terminals of the ele ment be kept outside of the vacuum.
Code Compliance
Chromalox manufac tures the highest quality heaters and controls and, where applicable,
in compliance with such codes as the Canadian Standards Association (CSA), Underwriters
Laboratories Inc. (UL) and Verification of Devices for Europe Testing and Certification
Institute (VDE) and CE.
Installation Guidelines
Wiring
Must be in accordance with The National Electrical Code (NEC). It is important to
use the correct wire gauge to carry the amperage required. A wire not large enough
can overheat, become brittle and break. The ambient temperature must also be considered
in choosing the correct type of wire and insu lation. Make sure wiring to terminals
is tight. Keep terminals away from heat, if possible. (For higher temperatures,
contact your Local Chromalox Sales office.)
Mounting Methods
Elements can be supplied with threaded fittings for mounting thru walls of tanks,
ovens, etc. Compression threaded fittings are also available for easy field installation.
Rings, clips, brackets and washers can also be attached to elements for mounting
purposes.
Easy Bending
To put heat where it is needed, tubular elements can be bent to fit most requirements.
See following pages for customer bending and factory bending details. Bending should
be done around a smooth round object such as a piece of pipe. For mini mum bending
radii, see Bending Guidelines.
Triangular Cross-Section
These unique cross-sectioned elements are specially designed for high element surface
temperature applications, and wherever extreme rigidity is required.
Triangulation
A patented extra step by Chromalox to increase insulation density and maximize heat
transfer and operating life. This method of compaction increases uniformity of resistance
wire spacing to help eliminate hot and cold spots. It also increases the rigidity
of the element, which is an advantage in some applications.
The terminal ends of these elements are re-rounded to facilitate the use of threaded
fittings or other mounting methods.
The heart shaped cross-section is recom mended for certain heavy duty applications.
It has added structural strength, achieved through die pressing, which resists deform
ation or sagging when installed in the flow of high velocity air or thick oils and
compounds, or in high surface temperature air heating.
Table 1: Sheath Material Dimensions for Tubular Heaters
|
Dimension (In.)
|
Terminal Size
|
Sheath Material
|
A
|
B
|
C
|
D
|
E
|
F
|
G
|
Copper
|
1
|
1
|
3/8
|
21/64
|
3-3/8
|
1-1/2
|
1±1/16
|
#10-32
|
Steel or INCOLOY ®
|
1
|
1
|
3/8
|
21/64
|
3-3/8
|
1-1/2
|
1±1/16
|
#10-32
|
Copper, Steel or INCOLOY ®
|
1
|
1
|
1/2
|
15/32
|
3-7/16
|
2-1/2
|
13/16±1/16
|
#8-32
|
1. See complete heater dimensions in table on product pages.
|
Tubular Heater Modifications
World Leader in the Manufacture of Electric Heating Elements
Chromalox offers the most complete line of tubular heaters avail able. Standard
diameters are:

Round Cross Section
Highly adaptable where elements must be bent particularly if bending is performed
in the field.
Triangular Cross Section
Patented process produces elements with the closest possible dimensional control.
Triangulated Cross Section
Flat pressed. Patented process provides large contact area for clamp-on applications.
This means more efficient heat transfer, fewer elements since higher element ratings
may be employed.
Voltage or Wattage
Heaters can be made for operation on any voltage and rated at any wattage suitable
for the application within practical limits. For voltages higher than 480V, specify
high voltage terminal construction. See Component section Tubular Heater (0.475
or 1/2" diameter only).
Special Wattage Distribution
Heaters can be made with higher wattages toward the end of the heated section to
help offset losses in certain applications. Check with your Local Chromalox Sales
office for additional information.
Tubing
Standard industrial grade wall thickness:
Repressed Bends
Tubulars can be bent to tighter radii at the factory. Bends are then repressed to
ensure re-compaction of insulation for long life. Customer bending on larger radii
does not require repressing. (See Factory Bending Guidelines in this section).
Sheath Length
Larger diameter heaters can be made in unspliced lengths up to 51 feet. This eliminates
the need for a spliced joint which is always a possible weak point that might cause
premature heater failure.
Table 2: Tubular Heater Sheath Length
Element Dia. (In.)
|
Max. Heater Length
(Ft. ± 1%)
|
0.2
|
10
|
0.246
|
40
|
0.375
|
40
|
0.315
|
40
|
0.43
|
40
|
0.475
|
51
|
3/8
|
17±1/8"
|
1/2
|
17±1/8"
|
Note:Single-end elements have a maximum sheath length of 10 feet.
|
Terminal Construction
Many choices to suit your application. Tubular elements gener ally have a terminal
for electrical connection at each end. Single end construction has both terminals
at the same end.
UL and CSA
Chromalox tubular heaters can be furnished as UL Recognized and CSA Certified components
with the addition of a terminal end seal. Terminal end seals can be added to stock
elements and shipped in one week. (UL File E198480, Guide UBJY2, CSA File 40859).
Use “end seal/moisture barrier” in place of end seal.
VDE and CE
Chromalox tubular heaters can be furnished as VDE Certified and CE certified. Contact
your Local Chromalox Sales office.
Wide Choice of Sheath Materials
Available to meet a wide variety of applications. Standard sheath materials are:
INCOLOY ® steel, type 304 and 316 stainless steel, copper, INCONEL®
and MONEL®. In addition, titanium and other 300 series stainless steel
sheaths are available upon request. For applications requiring other materials,
contact your Local Chromalox Sales office.
Cold Section
Longer cold ends can be supplied, as required, up to 20 inches. For longer cold
ends, contact your Local Chromalox Sales office.
Factory Bending
Tighter bends can be made at the factory. Tubular heaters can be formed to many
dif ferent shapes to suit your application. This is done by specially designed bending
tools and repressing dies for bending on many different radii.
Additional Features
Many additional fea tures are available for the difficult jobs which require custom
designed elements employing Chromalox's vast engineering experience.
Threaded Fitting

Table 3: Threaded Fittings
Element Dia. (In.)
|
Fitting Material
|
Mtg. Hole Dia. (In.)
|
Max. Wall Thickness (In.)
|
Thrd. Size
|
Dimensions (In.)
|
F
|
A
|
B
|
0.246
|
Brass
|
13/32
|
7/32
|
3/8 - 24
|
15/32
|
7/8
|
0.315
|
Brass
|
15/32
|
5/16
|
7/16 - 28
|
13/16
|
7/8
|
3/8
|
Brass
|
17/32
|
5/16
|
1/2 - 28
|
13/16
|
7/8
|
1/2-0.475
|
Brass
|
21/32
|
5/16
|
5/8 - 24
|
13/16
|
1
|
0.246
|
Steel
|
13/32
|
7/32
|
3/8 - 24
|
15/32
|
7/8
|
0.315
|
Steel
|
15/32
|
5/16
|
7/16 - 28
|
13/16
|
7/8
|
3/8
|
Steel
|
17/32
|
5/16
|
1/2 - 28
|
13/16
|
7/8
|
1/2-0.475
|
Steel
|
21/32
|
5/16
|
5/8 - 24
|
13/16
|
1
|
0.246
|
Stainless Steel
|
13/32
|
7/32
|
3/8 - 24
|
15/32
|
7/8
|
0.315
|
Stainless Steel
|
15/32
|
5/16
|
7/16 - 28
|
13/16
|
7/8
|
3/8
|
Stainless Steel
|
17/32
|
5/16
|
1/2 - 28
|
13/16
|
7/8
|
1/2-0.475
|
Stainless Steel
|
21/32
|
5/16
|
5/8 - 24
|
13/16
|
1
|
Tubular Heater Factory Bending Guidelines
Note: OAL represents overall length.


Factory Minimum Bends for Tubular Heaters
Table 4: Factory Minimum Bends
Element Dia. Inside & Sheath
|
Inside R1,2,3
|
A
|
B1,2
|
C
|
Inside D
|
E
|
1/2" INCOLOY ® 5Steel & Copper : ∆
|
3/4
1/2 1,2,3
|
1-3/8
1-3/8
|
1
1 1,2
|
1-1/2
1-1/2
|
5
8
|
8
6
|
0.475" INCOLOY ®Steel & Copper
|
3/4
1/2
|
1-3/8
1-3/8
|
1
1
|
1-1/2
1-1/2
|
3
3
|
8
6
|
0.430" INCOLOY ®Steel & Copper
|
7/16
7/16
|
1-3/8
1-3/8
|
1
1
|
1
1
|
3
3
|
8
6
|
3/8" INCOLOY ® 5Steel & Copper : ∆
|
9/16
3/8
|
1-3/16
1-3/16
|
1
1
|
1-1/2
1-1/2
|
3-3/4
6
|
5
3
|
0.375" INCOLOY ®Steel & Copper
|
3/8
3/8
|
1-3/16
1-3/16
|
1
1
|
1
1
|
2-5/8
2-5/8
|
5
3
|
0.315" INCOLOY ®Steel & Copper
|
9/16
5/16
|
1-3/16
1-3/16
|
1
1
|
1-1/2
1-1/2
|
2
2
|
5
3
|
0.260" INCOLOY ®Steel & Copper
|
1/4
1/4
|
1-1/8
1-1/8
|
1
|
1
1
|
1-7/8
1-7/8
|
5
3
|
0.245" INCOLOY ®Steel & Copper
|
3/8
1/4
|
1-1/16
1-1/16
|
1
1
|
1-3/16
1-3/16
|
1-1/2
1-1/2
|
5
3
|
0.200" INCOLOY ®
|
1/4
|
1/4
|
1
|
3/4
|
1-1/4
|
5
|
To Order
Specify model, PCN, volts, watts, special features, if required, and quantity. Specify
for Factory Formed Tubulars: A. Figure number. B. A, B 1,2, C, D, E, H, J, K, L
1,2and R 1,2,3dimension as required. C. N - number of turns, Dia. - Element Diameter-
aid < - angle as required. D. Material for threaded fittings. E. Special terminal
type. F. Position of crown (flat side) of element (TC, TI, TS only). G. Submit sketch
with special details. Notes
- These are general guidelines only. Special dimensions and configurations
are possible. Contact your Local Chromalox Sales office.
- A dimension can be less if no fittings are required.
- C dimension may need to be greater if special fittings are used.
- E dimension is a minimum when R dimension is less than customer minimum
bending radius.
- Heart Shaped cross-section only.
Tubular Heating Terminal Options
Standard, Alternate, and Moisture Resistant Terminals
|
Tubular Heating Customer Bending & Accessories
Brackets, Discs & Clips
Various types of brackets and clips can be fastened to the heaters to facilitate
installation. The following are typical. For other brackets to meet your installation
requirements, contact your Local Chromalox Sales office.

Compression Fittings
Field Installed Compression Fittings

For 0.475, 0.315 and 0.246" diameter elements . Available in both brass and
steel, these fittings have been tested to 600 psi hydrostatic pres sures and may
be used in tank walls for liquid immersion as well as in air ducts and a variety
of other applications.
Compression fittings do not require brazing and can be field mounted in minutes.
They may be positioned anywhere along the cold section of the heating element. Do
not position over heated section. Cannot be installed over terminal Type #26 (Hermetic
Seal), and some other terminals wider than sheath diameter.
Customer Bending
Simple element configurations can be made easily in the field from stocked tubulars
listed in this catalog. If copper or stainless sheaths are selected, specify “To
be fully annealed for bending.” Elements can be bent around any round, smooth surface
of the right diameter.
Three precuations should be observed to prevent damage to the element:
Terminal end bending can be done with pipe section of slightly larger diameter than
sheath. A minimum 1" straight section should be left at the end.
Note
To protect sheath, copper sheet can be bolted to vise jaws and end of pipe can be
filed to remove sharp edge.
Before bending, it is best to lay out and dimen sion the configuration. Also, it
is best to start bending from the center of the heater and work toward the terminal
ends.
Customer Bending

Tubular Heater Design & Installation Guidelines
Design Considerations
Sheath Material —For resisting corrosion inherent in the process
or environment and for withstanding the sheath temperature required
— Standard sheath materials are INCOLOY ® , steel, copper and stainless
steel (type 304). Other types of stainless steel, MONEL ®, titanium and
INCONEL are available.
Job Requirements — The calculation of total heat requirements for
an application is outlined in Technical section. For assistance, contact your Local
Chromalox field sales engineer who will be glad to contribute his judgement, experience
and knowledge in solv ing your heating problem.
After the specific heater size and rating has been tentatively selected, the watt
density must be checked against the curves in Techni cal section.
If the heater selected has a watt density higher than stipulated by the curve, consider
these alternatives:
- Use more heaters of a lower watt density to obtain the required kW capacity.
- Reduce the kW capacity needed by reducing heat losses and/or allowing for a longer
heat-up time.
Watt Densities — The watt density of the element, or watts per
square inch of element heated area, should be low for heating asphalt, molasses
and other thick substances with low heat transferability. It can be higher for heating
air, metals, liquids and other heat-conducting materials. See curves in Technical
section for determining allowable watt densities.
When high operating temperatures are needed, watt density must be limited in order
not to exceed the maximum sheath tempera ture. Watt density is given in the specifications
for each tubular heater.
In general, a viscous material with low thermal conductivity requires a low watt
density. Higher watt densities can be used with thinner liquids and with materials
of high thermal conductivity. Premature loss of the element due to excessive temperature
may result if the material’s heat-take-away ability is low. Also, the material may
be charred, carbonized or its chemical makeup altered by overheating.
Terminal Selection — Stocked tubulars are shipped with standard
terminals, see Terminal Options in this section. Many other terminals and terminal
end seals are available made to order.
CAUTION— Protect terminals from possible contamination from surrounding atmospheres
such as oil fumes, chemical vapors from other processes, moisture, weather, etc.
MgO insulation is hygroscopic.
Vacuums — Tubular heaters operate at higher temperatures in a vacuum
because there is no air to take away the heat. Therefore, watt densities are recommended
to be 20 to 30% lower. It is recommended terminals of the ele ment be kept outside
of the vacuum.
Code Compliance — Chromalox manufactures the highest quality heaters
and controls and, where applicable, in compliance with such codes as the Canadian
Standards Association (CSA), Underwriters Laboratories Inc. (UL) and Verification
of Devices for Europe Testing and Certification Institute (VDE) and CE.
Installation Guidelines
Wiring — Must be in accordance with The National Electrical Code
(NEC). It is important to use the correct wire gauge to carry the amperage required.
A wire not large enough can overheat, become brittle and break. The ambient temperature
must also be considered in choosing the correct type of wire and insu lation. Make
sure wiring to terminals is tight. Keep terminals away from heat, if possible. (For
higher temperatures, contact your Local Chromalox Sales office.)
Mounting Methods — Elements can be supplied with threaded fittings
for mounting thru walls of tanks, ovens, etc. Compression threaded fittings are
also available for easy field installation. Rings, clips, brackets and washers can
also be attached to elements for mounting purposes.
Easy Bending — To put heat where it is needed, tubular elements
can be bent to fit most requirements. See following pages for customer bending and
factory bending details. Bending should be done around a smooth round object such
as a piece of pipe. For mini mum bending radii, see Bending Guidelines.
Triangular Cross-Section
These unique cross-sectioned elements are specially designed for high element surface
temperature applications, and wherever extreme rigidity is required.
Triangulation — A patented extra step by Chromalox to increase
insulation density and maximize heat transfer and operating life. This method of
compaction increases uniformity of resistance wire spacing to help eliminate hot
and cold spots. It also increases the rigidity of the element, which is an advantage
in some applications.
The terminal ends of these elements are re-rounded to facilitate the use of threaded
fittings or other mounting methods.
The heart shaped cross-section is recom mended for certain heavy duty applications.
It has added structural strength, achieved through die pressing, which resists deform
ation or sagging when installed in the flow of high velocity air or thick oils and
compounds, or in high surface temperature air heating.

Tubular Heater Modifications
World Leader in the Manufacture of Electric Heating Elements —
Chromalox offers the most complete line of tubular heaters avail able. Standard
diameters are:
Round Cross Section — Highly adaptable where elements must be bent
— particularly if bending is performed in the field.
Triangular Cross Section — Patented process produces elements with
the closest possible dimensional control.
Triangulated Cross Section — Flat pressed. Patented process provides
large contact area for clamp-on applications. This means more efficient heat transfer,
fewer elements since higher element ratings may be employed.
Voltage or Wattage — Heaters can be made for operation on any voltage
and rated at any wattage suitable for the application within practical limits. For
voltages higher than 480V, specify high voltage terminal construction. See Component
section Tubular Heater (0.475 or 1/2" diameter only).
Special Wattage Distribution — Heaters can be made with higher
wattages toward the end of the heated section to help offset losses in certain applications.
Check with your Local Chromalox Sales office for additional information.
Tubing — Standard industrial grade wall thickness:
Repressed Bends — Tubulars can be bent to tighter radii at the
factory. Bends are then repressed to ensure re-compaction of insulation for long
life. Customer bending on larger radii does not require repressing. (See Factory
Bending Guidelines).
Sheath Length —Larger diameter heaters can be made in unspliced
lengths up to 51 feet.
This eliminates the need for a spliced joint which is always a possible weak point
that might cause premature heater failure.
Element Dia. (In.)
|
Max. Heater Length
(Ft. ± 1%)
|
0.2
|
10
|
0.246
|
40
|
0.375
|
40
|
0.315
|
40
|
0.43
|
40
|
0.475
|
51
|
3/8
|
17±1/8"
|
1/2
|
17±1/8"
|
Note — Single-end elements have a maximum sheath length of 10 feet.
|
Terminal Construction — Many choices to suit your application.
Tubular elements gener ally have a terminal for electrical connection at each end.
Single end construction has both terminals at the same end.
UL and CSA — Chromalox tubular heaters can be furnished as UL Recognized
and CSA Certified components with the addition of a terminal end seal. Terminal end
seals can be added to stock elements and shipped in one week. (UL File E198480,
Guide UBJY2, CSA File 40859). Use “end seal/moisture barrier” in place of end seal.
VDE and CE — Chromalox tubular heaters can be furnished as VDE
Certified and CE certified. Contact your Local Chromalox Sales office.
Wide Choice of Sheath Materials — Available to meet a wide variety
of applications. Stan dard sheath materials are: INCOLOY® , steel, type
304 and 316 stainless steel, copper, INCONEL® and MONEL®.
In addition, titanium and other 300 series stainless steel sheaths are available
upon request. For applica tions requiring other materials, contact your Local Chromalox
Sales office.
Cold Section — Longer cold ends can be supplied, as required, up
to 20 inches. For longer cold ends, contact your Local Chromalox Sales office.
|
Dimension (In.)
|
Terminal Size
|
Sheath Material
|
A
|
B
|
C
|
D
|
E
|
F
|
G
|
Copper
|
1
|
1
|
3/8
|
21/64
|
3-3/8
|
1-1/2
|
1±1/16
|
#10-32
|
Steel or INCOLOY®
|
1
|
1
|
3/8
|
21/64
|
3-3/8
|
1-1/2
|
1±1/16
|
#10-32
|
Copper, Steel or INCOLOY®
|
1
|
1
|
1/2
|
15/32
|
3-7/16
|
2-1/2
|
13/16±1/16
|
#8-32
|
1. See complete heater dimensions in table on product pages.
|
|
Factory Bending — Tighter bends can be made at the factory.
Tubular heaters can be formed to many dif ferent shapes to suit your application.
This is done by specially designed bending tools and repressing dies for bending
on many different radii.
Additional Features — Many additional fea tures are available for
the difficult jobs which require custom designed elements employing Chromalox's vast
engineering experience.
Element Dia. (In.)
|
Fitting Material
|
Mtg. Hole Dia. (In.)
|
Max.Wall Thickness (In.)
|
Thrd. Size
|
Dimensions (In.)
|
F
|
A
|
B
|
0.246
|
Brass
|
13/32
|
7/32
|
3/8 - 24
|
15/32
|
7/8
|
0.315
|
Brass
|
15/32
|
5/16
|
7/16 - 28
|
13/16
|
7/8
|
3/8
|
Brass
|
17/32
|
5/16
|
1/2 - 28
|
13/16
|
7/8
|
1/2-0.475
|
Brass
|
21/32
|
5/16
|
5/8 - 24
|
13/16
|
1
|
0.246
|
Steel
|
13/32
|
7/32
|
3/8 - 24
|
15/32
|
7/8
|
0.315
|
Steel
|
15/32
|
5/16
|
7/16 - 28
|
13/16
|
7/8
|
3/8
|
Steel
|
17/32
|
5/16
|
1/2 - 28
|
13/16
|
7/8
|
1/2-0.475
|
Steel
|
21/32
|
5/16
|
5/8 - 24
|
13/16
|
1
|
0.246
|
Stainless Steel
|
13/32
|
7/32
|
3/8 - 24
|
15/32
|
7/8
|
0.315
|
Stainless Steel
|
15/32
|
5/16
|
7/16 - 28
|
13/16
|
7/8
|
3/8
|
Stainless Steel
|
17/32
|
5/16
|
1/2 - 28
|
13/16
|
7/8
|
1/2-0.475
|
Stainless Steel
|
21/32
|
5/16
|
5/8 - 24
|
13/16
|
1
|
Compression Fittings
Field Installed Compression Fittings — For 0.475, 0.315 and 0.246"
diameter elements. Available in both brass and steel, these fittings have been tested
to 600 psi hydrostatic pres sures and may be used in tank walls for liquid immersion
as well as in air ducts and a variety of other applications.
Compression fittings do not require brazing and can be field mounted in minutes. They
may be positioned anywhere along the cold section of the heating element. Do not
position over heated section. Cannot be installed over terminal Type #26 (Hermetic
Seal), and some other terminals wider than sheath diameter.
Field Installed Compression Fittings
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Customer Bending
Simple element configurations can be made easily in the field from stocked tubulars
listed in this catalog. If copper or stainless sheaths are selected, specify
“To be fully annealed for bending.” Elements can be bent around any round, smooth
surface of the right diameter.
Three precuations should be observed to prevent damage to the element:
- Radius of the round object, around which the element is bent, should
be no smaller than the minimum radius for the element, as shown in the table below.
- Sharp edges of tools should not be permitted to gouge the element
sheath while bending.
- End of cold section of the element should not fall within the bend
nor come within 1/4" of either side of the bend. To locate end of cold section,
see dimensions for the element on its catalog page and determine as follows:
Example — To locate end of cold sectio n of TRI-1645 tubular element, refer t o
the individual product page . Sheath length: 16 "Less heated length: 9-1/8 "Total
cold length: 6-7/8 "Cold length of each en d (6-7/8" ÷ 2) = 3-7/16 ", Terminal
end bending can be done with pipe section of slightly larger diameter than sheath.
A minimum 1" straight section should be left at the end.
Note — To protect sheath, copper sheet can be bolted to vise jaws and end
of pipe can be filed to remove sharp edge.
Before bending, it is best to lay out and dimen sion the configuration. Also, it
is best to start bending from the center of the heater and work toward the terminal
ends.

Download the Tubular Heater Design and Installation Guidelines