Welcome to our
Kiln / Furnace Studio. Duralite has been
serving glass artists, ceramic artists, teachers and craftspeople
for 60 years.
Duralite Inc. manufactures high quality heating
elements for electric kilns of all makes and models. We supply “replacement” heating
elements for standard brand kilns, and we also manufacture
heating elements for special applications
such as custom built kilns and annealers. Duralite
heating elements are made to match or exceed the needs of your kiln and
Duralite elements are also value priced at factory discount
also offer a quality line of electrical controls, wiring and hardware products
to complete your project
with professional results. These products have been field tested and proven
successful by artists and crafters like your self.
You can now order
many of our stocked products through our secure online
shopping site. Complete with product descriptions,
order numbers, photos, and prices.
Most items that are in stock will be shipped the next business day.
We are excited about our
new web site. The improvements
we've made are just the beginning.
In the months ahead,
we plan to expand the information you see here to make
it a great resource for your needs. If
you have any special requests, comments or suggestions
for us, we'd love to hear from you.
Kiln Heating Elements
Custom Heating Elements
Stocked Heating Elements
Thermocouples, Thermocouple wire, and
Power Controls- Switches, Relays, Solid State Relays
Lead Wire, Wire Connectors and Terminal Blocks
Temperature Control Packages
maintains an extensive database of replacement heating element
specifications for most popular kiln brands and models. Duralite
heating elements are made to match or exceed the specs of your
Because you are purchasing at factory discount prices, you will find our prices
If this is a first time replacement request, use the form link below. Provide
us with as much information as you can about your kiln. We
find that many kilns of the same make and model have different
heating element designs so it is important that we find out
what exactly you have. If you think it will help, you can even
send us a sample of the old element.
For repeat orders in the future, just refer to the assigned Duralite “Part
We will have all the necessary information saved from your first order. Our
friendly staff will reply promptly with pricing and delivery
Custom Kiln Heating Elements
Building a custom kiln or furnace? Whether
it’s a Front loader, Top loader or Bell/Hat style - for
annealing, slumping, fusing, or casting glass - we can
help. Just fill out the “Custom Heating Element Request” form.
Duralite's engineering staff will then assist you in the
design process, to get your furnace operational. First,
we will configure a custom element layout using your design
and power requirements. Then we will also recommend any
necessary wiring hardware and controls to complete the
Duralite STOCK HEATING ELEMENTS are purchased directly from our online
store. These elements are designed for common voltages and wattages
and are well suited to the veteran do-it-yourselfer. Use the
guide-lines provided below to help make your selection. Please review
the information carefully as we do not accept returned elements that
have been fired or modified. We accept returns on elements within
30 days of purchase if they have not been installed, altered or damaged,
and returned shipping paid by customer, for a 20% restocking fee.
the “total wattage” required for your application.
- Select the voltage that matches (or is the closest
to) your building power supply.
- Select the quantity of elements that will fill
your wattage requirements. The number of elements can be
multiples or combination of any wattage size of elements.
For example, If you need 10,000 watts of heat you can use
(3) 3,000 watt elements and (1) 1,000 watt element
- Determine that the selected elements will physically
fit into your application using the element coil diameter
and the coil stretch length data listed in the chart. The
elements are shipped unstretched and must be stretched to
length prior to installation. Each element has a minimum
and maximum stretch range. If an element happens to be to
long for your application then consider using multiple lower
wattage elements which are have shorter stretch lengths.
Stock Heating Elements definitions:
Volts - Amps - Watts
element Watts is based on the voltage
listed in the table. The element can be operated at different
voltages but the actual Wattage will be dependent on your building’s
not operate the elements at voltages that exceed the listed
volts by 10%. You can calculate the actual wattage and amps
of the element will be for your supply voltage by using the
example shown below.
actual amperage and wattage is needed to determine your electrical
service requirements such as the fuse or circuit breaker size,
power contactor size, and the size of the feed wires.
example below determines the actual element amperage and wattage.
Heating Element, DURA005677,115 Volt -10 Amp –1150
Find the actual amps and watts if connected to
a 120 volt supply.
Step 1:Calculate the element “Resistance” (OHMS),
using the table data Voltage and Amps.
VOLTS ÷ AMPS =
115 VOLTS ÷ 10 AMPS = 11.5 OHMS
Find the “actual” element AMPS when
connected to 120 volt supply
VOLTS ÷ OHMS = AMPS
120 ÷ 11.5 = 10.43 AMPS (actual)
Then to find the “actual” element
VOLTS x AMPS = WATTS
120 X 10.43 = 1251.6 WATTS (actual)
This is the
element’s “Outside Diameter”. If you are mounting the element
in a groove, you should make sure that the Coil Diameter is
less than the groove size. If you are mounting the element
over a mullite rod, the diameter should be larger than
the mullite diameter. Remember stretching the coil will
the diameter slightly.
elements are shipped “close-wound” meaning that the coils have
not been stretched apart, which is required before the element
can be used. The element can be stretched to any length within
the “Install Length” range as listed. Stretching the element
does not effect the electrical ratings, but do not attempt
to shorten or cut down the element (except for the tails)
to make it shorter.
Element Stretching Procedure
- Bench vise
- Locking pliers
- Safety Glasses
is a little bit of a trial and error process. If you have
a long bench with a vise you can stretch elements with one
person, if not you will need two people. Mark out the element’s
installed length by measuring from the end that is held fixed. Firmly
clamp the fixed end in position, and then pull the heating
element 10% beyond your desired length. Note the distance
where you stretched to, then allow the element to relax fully.
Very likely you will not have stretched it far enough. Now
stretch slightly beyond your first stretch mark. Mark the spot
again where you stretched to. After you have done this several
times, you will quickly determine how far you must stretch
an element to obtain the proper length.
If you overstretched
the element there are a few ways to correct this. If you are
only slightly beyond your installed length, loosely shaking
the element with the fixed end still clamped will usually reduce
the length due to memory effect. If you are well beyond the
installed length and shaking will not reduce the length sufficiently,
you will have to compress and re-stretch the element. If necessary,
you may have to run a rod down the interior of the element
in order to compress it enough without extreme distortion.
cut element shorter to fit it into your kiln.
turns out of an element will cause elements to draw more amperage
and run hotter. In the best case you will shorten its working
life; in the worst case you may cause a fire.
Maximum Wire Temperature
This is the
maximum operating temperature for the alloy wire of the element.
Element life will be affected by the Kiln operating temperature.
The higher the kiln operating temperature the shorter element
life will be.
STOCK Heating Elements have 12 in. terminal leads of double
twisted wire. The terminal leads can be trimmed shorter if
stocks a variety of off the shelf temperature controllers
to meet the needs of most heating applications. Features
single set point ON-OFF temperature ramping and programmable
- High Temperature Limit Controls
- Temperature Meters
- Inputs : Thermocouple Type-K,
- Outputs: relay contacts , 4-32vdc,
- Refer to our listings for details
on options and other specific details.
here to order.
Thermocouple wire, and Accessories
a wide range of sheath materials including stainless, mullite,
and alumina of various lengths, diameters and configurations.
sensors, type K, R, S
extension wire, type K, R, S
connectors, type K, R, S
Click here to order.
Switches, Relays, Solid State Relays
Controllers feature solid state and electromechanical relays
that are designed for heating applications.
Power Controllers are sized by:
- Supply voltage
- Power supply configuration (single or three
phase) which determines the number of poles
- Current handling
- control signal to activate relay
Click here to order.
direct replacement relays for many of the popular kiln
Mercury Displacement Relays-
feature high cycle life outlasting mechanical contactors
SSR, Solid State relays-
deliver the finest control, lowest power consumption,
and will give the longest element life
Lead Wire, Wire
Connectors and Terminal Blocks
The proper element connectors and wiring hardware will
maximize your heating element life and performance. Electrical
connections are often the weakest
link in a heating element system. You should only use electrical connectors
that are suitable for the high temperatures and compatible with the metal
alloy of the heating elements. Using electrical connectors that are not
compatible will cause a corrosion to occur at the connection
area. This corrosion increases
the electrical resistance at the connection and the higher resistance will
hamper the heating element performance.
lead wire should have insulation that is suitable for the
high temperatures and the wire size must be large enough
the electrical current or ampere load of the heating element(s).
Using undersized wire will cause the lead wire to over heat,
and will also hamper the heating element performance.
Click here to order.
Duralite Temperature control packages
are completely assembled, wired, tested and ready to be installed.
Power supplies include 120/ 208/ 240/ 480 volt, 60-150 amp
single or three phase. Each package is specially designed
to fit your specific application and
needs. Backed with our support, you will have the confidence
that you are getting the best value, quality and performance
for your application.
All Temperature Control packages use top quality grade components.
Panel fabrication follows the National Electrical Code requirements.
The metal enclosure is a rugged industrial quality grade. Wiring
knockouts are pre-punched to simplify installation, and mounting
feet are provided for wall mounting.
All the controls are pre-programmed to
get you up and running as fast and as easy as possible. Complete technical
installation, maintenance instructions, and drawings are provided. Factory
start up assistance can be provided when needed.
Click here to order.
Contact us for pricing and delivery
Quartz tubing is a viable method to install heating elements inside kilns.
The quartz tubes provide a relatively easy and stable means to mount
the elements and it also has many other benefits. The element is
mounted inside the tube thus providing electrical insulation. The quartz
electrical insulator yet it passes heat with very little absorption.
The heating element is protected from contamination which is one
of the greatest causes of premature element failure. Heating element
and spalling is contained inside the quartz tube thus protecting
your work from any debris. Quartz tubes can operate at temperatures
F. If a rapid cool down is desired the quartz tube can be used to
pass cool air directly thru the kiln walls.
above is a typical example showing a quartz tube mounted
inside a kiln. Quartz tubes generally are mounted on the
the roof. This example uses heating element wire as hangers
for the quartz tube. The wire is formed with a loop on
one end for the tube. The remainder of the wire is then twisted
together forming a straight portion which is passed thru
small hole drilled thru the kiln wall to the outside of
the kiln. Locate wire hangers about 8-10 inches from each
the quartz tube and then one in the middle of the tube.
The hanger wire is then trimmed to length and fixed to the
kiln wall using sheet metal screws. Sometimes it is easier
to install the heating element inside the quartz tube before
mounting the quartz tube inside the kiln. Your kiln construction
will determine which procedure is best. Orient tubes horizontally
for best element operation. Quartz is strong but should
not be stressed during mounting and do not use it for any
Click here to order.
This is a traditional
material choice in high temperature, high hot strength, and
thermally shock resistant products. It is a good thermal and
electrical insulator – even at very high temperatures. It has
outstanding hot load-bearing properties, and it is resistant
to many corrosive environments. It is, in short, the key ingredient
in many refractory and ceramic products.
- Good high temperature
- Good thermal shock resistance
- Excellent thermal stability
- Resistance to most chemical
attack; it has excellent stability in acid metal slags and is insoluble
in most acids
- Resistance to oxidation and
attack by furnace atmospheres
- Resistance to abrasion
- Good electrical resistivity
industrial, commercial and other industries:
Protection tubes, Electrical insulators, Element center tubes, mounting
rods and rollers for Heaters, furnaces, and kilns.
Click here to order.
Disclaimer: The contents
of this document are provided “AS IS”. This information could
contain technical inaccuracies, typographical errors and out-of-date
information. This document may be updated or changed without
notice at any time. Use of the information is therefore at
your own risk. In no event shall Duralite be liable for special,
indirect, incidental or consequential damages resulting from
or related to the use of this document.
Warning: Some of these
discussions deal with electricity and electrical connections. It
cannot be stressed enough – you must always disconnect
the power to equipment that you need to service before
up any electrical boxes or panels. If you have any questions
or are not qualified to work on the equipment – hire a