The 7 Best Ways to Use Tubular Heaters in 2023

Press 'Allow' to verify, that you are not a robot

View Details

Tubular heaters are essential heating sources in many applications requiring electric heat. Their versatility allows them to adapt to various requirements. Tubular heaters can be utilized in their straight configuration or bent into different shapes. They can be used in open air, clamped to surfaces, embedded, or even cast into metals, delivering heat up to several hundred degrees Fahrenheit.

Bucan's tubular heaters feature a heating core composed of 80% nickel and 20% chromium high-grade coiled resistance wire. This core is welded at both ends to pins that provide a cold section of varying lengths based on the application. A precisely centered coil-pin assembly is encased in a heavy gauge, oversized metal tube, embedded in a 96% pure, high-grade MgO insulation medium. Following a roll-reducing process, the outer tube's diameter is reduced to its final size, while compacting transforms the MgO matrix into a dense solid that serves as an excellent conductor of heat and provides high dielectric strength electrical insulation. The heaters are then annealed in a high-temperature furnace to remove internal stresses accumulated during the shaping process, softening them for further processing, before final electrical terminations are added.

Applications of Tubular Heaters

• Forming Machines
• Heating Molds & Platens
• Immersion in Liquids
• Radiant & Convection Heating
• Embedded or Cast into Metal

Specifications of Tubular Heaters

The two main factors influencing the durability of a tubular heater are:

• Sheath Material
• Watt Density

The corrosiveness of the medium and its operating temperature dictate the appropriate sheath material. The following table provides a summary of different sheath materials, their maximum allowable temperatures, and suitable applications.

The watt density affects the temperature that the sheath of a heating element will achieve under specific conditions.

Watt Density Calculation

Watt density is determined using an appropriate formula, taking into account:

• Application temperature
• Application conditions
• The maximum recommended temperature for the selected sheath material.
• The maximum watt density recommended for the material being heated.
• In cases where scale or sludge formation is possible, lower watt densities should be used.
• When heating gases, the input gas speed and outlet temperatures should inform watt density calculations.
• In vacuum conditions, drop watt density by 20% to 30% because heaters primarily transfer heat through radiation in the absence of air.

Maximum Watt Density Ratings for Various Solutions for Tubular Water Heaters

Crimped Fittings

*Fittings made from different materials are available

Foshan Osno contains other products and information you need, so please check it out.

Welded Fittings

*Fittings made from different materials are available

Brazed Fittings

*Fittings made from different materials are available

"C" Clamp

Mounting Bracket

Contact Us for Tubular Electric Heaters with Thermostat or Electric Tube Heaters with Thermostat.

Bending Tubular Heaters

Annealed tubular heaters can be bent. The minimum inside bend radius should not be less than the recommended values shown in the table below. For optimal results, begin bending from the center of the heater and proceed towards the ends. Ensure that the connection between the cold pin and the coil stays outside the bent area, maintaining a minimum of 1/2" clearance from the bend. The sketch below illustrates the required guidelines.

*For tighter bend radii, please consult our factory.

Standard Bending Formations

Re-compaction of Tubular Heaters

When bending industrial tubular heaters, the solid MgO insulation can develop cracks, particularly at sharp bends. These flaws may become weak points that increase the risk of overheating and dielectric failure. This issue is even more pronounced under high wattage or temperature conditions. Therefore, it is crucial to re-establish tightness at the bent locations by recompressing the materials.

For more information about Tubular Water Heaters in Canada, contact Bucan today.

Mounting Tips for Finned Tubular Heaters

• Tubular heaters expand when heated; allow at least 1% of the element length for this expansion in your design.
• When attaching a tubular heater to a surface, fully tighten the middle clamp screws, but ensure the end clamp screws are only tight enough to secure the heater while permitting some expansion, preventing detachment during heating cycles.
• For tubular heaters in grooves, the groove depth should be slightly less than the heater diameter by 0.008 - 0.010 inches for proper clamping.
• If insulating materials are in use, maintain an air gap between them and the heaters.
• Avoid placing electric terminals of tubular heaters in heated zones or vacuums.

Moisture Resisting Seals

The MgO insulating medium within tubular heaters is highly hygroscopic and may absorb moisture from its terminal ends. Moisture-resisting seals are used to inhibit moisture and contamination.

Silicone Resin Seals

Applying a silicone-based resin to the terminal ends of tubular heaters creates a moisture-resistant barrier that penetrates a short length of MgO insulation and remains effective at temperatures below 390°F.

RTV Seal

This silicone seal can withstand moisture and contamination at temperatures up to 450°F.

Epoxy Seal

A thermally cured liquid resin creates a durable moisture barrier effective at temperatures up to 250°F.

If you're interested in finding out more, visit our website for additional insights regarding the Tubular heater winding and manufacturing machine.