Cartridge Heaters

End Seals for your Hampton Controls Cartridge Heaters

Descriptions of some of our End Seals

Ceramic End Seal: 

• Excellent for high temperature applications up to 2500º F. Provides protection against some thicker liquids and dust, however it is not waterproof. Provides excellent mechanical strength and vibration resistance.

Teflon Seal End Seal:

• Teflon Seals are a mechanical seal constructed by compressing a solid piece of Teflon in the end of the heater creating a seal between the Teflon piece and sheath and a seal between the Teflon piece and the lead wire.
• Teflon lead wire is used in conjunction with the Teflon end seal. While Teflon has a temperature rating of 350º F., it softens slightly above 300º F. and can relax and compromise the seal.
• An unheated section of 1” at the end of the heater is generally required to avoid overheating the seal.

Mica End Seal: 

• ​Excellent for high temperature applications up to 2600º F. Provides good protection from contamination.

Cement End Seal:

• Provides protection against some thicker liquids and dust, however it is not waterproof. It is also somewhat brittle and subject to cracking in high impact or high vibration applications. Rated to 2600º F.

​Epoxy Potting End Seal:

• ​Provides a very good seal with excellent mechanical strength. However, it’s adherence to Teflon or silicone rubber lead wire is only fair. Bonds well to Duraflex lead wire. Rated to 600º F.

​Epoxy-Lite Potting End Seal:

• ​Provides similar mechanical properties as epoxy potting, however it is Rated to 650º F.

RTV End Seal:

• RTV Potting, when used in combination with silicone rubber insulated lead wire, provides the best seal of all options.
• The down side to silicone is that it is limited to 500º F. and while extremely flexible, it is not as strong mechanically as other options.
• Although the RTV is rated for 500º F., silicone rubber lead wire is only rated to 400º F. An option is to use Duraflex lead wire instead. Duraflex is rated to 1000º F. and has a heavy silicone coating.
• While Duraflex is not sold as a waterproof wire, it performs very well in wet environments.
• Another option is to use crimped on leads, then the power pins are sealed where they enter the heater and the type of lead wire does not matter.

Lava End Seal: 

• A swaged in lava plug protects the internal cartridge from contamination. Up to 1500 °F

Ceramic End Seal

Teflon End Seal

Mica End Seal

Cement End Seal

Epoxy End Seal

Epoxy-Lite Seal

Silicone Rubber
End Seal

Lava End Seal

Comparison Chart for End Seals

Cartridge Heater Construction Options

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Bent Heaters: An alternative to right angle leads.

Please note that the bend needs to be made in an unheated area of the heater.

Multi-Zone Heaters

Multi-Zone Heaters: Individually controlled heating zones. As many as 5 zones in 3/4" and 1" diameter heaters and 3 zones in other diameters. Leads are color coded for easy identification.

Cartridge Heater Double Ended Cartridge Heaters

Double Ended Heaters: Available with screw terminals, pins, and leads.

Distributed Wattage Cartridge Heaters

Distributed Wattage Cartridge Heaters are designed with the watt density varying along the length of the cartridge heater. The design compensates for heat losses along the edges of heated parts. This style is ideal for and typically used in platens and sealing bar applications. 

Distributed Wattage Cartridge Heaters –  When requesting this design, specify desired lengths in inches and wattage percentage.

Cartridge Heater Add-Ons

Hampton Controls offer a few of the options that can be added to swaged cartridge heaters and non swaged cartridge heaters.

Add-Ons	Description
	Stainless Steel Fittings: Many different sizes available in both SINGLE and DOUBLE NPT fittings.  "See Chart Below for Available Sizes"​
	Brass Fittings: Many different sizes available in both SINGLE and DOUBLE NPT fittings. ​ ​"See Chart Below for Available Sizes"​
	Strain Relief: Provides extra support for leads. Great for applications with lots of flexing.
	Flanges: Standard flange material is stainless steel. Flanges can be round or irregularly shaped. Contact Hampton Controls for standard and non-standard flange configurations. ​ • Flanges are 1/16” thick • Flanges also assist in heater removal. • Flanges can be welded on the lead end of the heater. • Flanges can be used to hold a heater in place to prevent backing      out during operation.

Mechanical Stops Also

• Weld Beads
• Tab Stops
• Custom Round Flanges
• Custom Rectangular Flanges
• Ideal for preventing heaters from sliding too far into the hole

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Specification Chart
Heater Diameter	1/4"	3/8"	1/2"	5/8"	3/4"	1"
NPT Thread Size	1/8"	1/4"	3/8"	1/2"	3/4"	1"
Brass "A"	.57	.70	.74	.80	.92	1.30
Brass "B"	.43	.56	.69	.87	1.06	1.44
Stainless Steel "A"	.62	.76	.77	.84	.96	1.27
Stainless Steel "B"	.46	.56	.67	.87	1.06	1.37

Specification Chart
Heater Diameter	1/4"	3/8"	1/2"	5/8"	3/4"	1"
NPT Thread Size	1/8"	1/4"	3/8"	1/2"	3/4"	1"
Brass "A"	.98	1.13	1.25	1.53	1.72	2.35
Brass "B"	.43	.56	.69	.87	1.06	1.37
Stainless Steel "A"	.98	1.13	1.25	1.53	1.72	CALL
Stainless Steel "B"	.43	.56	.68	.87	1.06	CALL

Non-Swaged Cartridge Heaters

Non-swaged cartridge heaters offer a cost effective solution where the performance of a swaged heater is not required.

Non-swaged heaters can be used at watt densities up to 45 watts per square inch and temperatures up to 1000°F. Non-swaged heaters offer tighter length tolerances than swaged heaters, making them ideal for applications such as platens where heaters are generally longer.

Non-swaged heaters can be built with 3 independent heat zones, distributed wattage, and/or internal thermocouples. Most of the lead configurations and options available for swaged cartridge heaters are also available for non-swaged cartridge heaters. Non-swaged heaters are not recommended for applications where there is is a lot of vibration or impact.

Non-Swaged Cartridge Heater Features

• Lead wires are UL rated to 550°C (1022°F)
• High temperature cement filling protects leads and internal parts. Epoxy and silicon rubber leads are available.
• Nickel chromium resistance wire stretched evenly throughout the length for even heat distribution.
• High purity MgO is vibratory filled for maximum heat transfer.
• 304 SS sheath for superior oxidation resistance.
• Welded end disc to prevent contamination and moisture absorption.

Non-Swaged Heater Specifications

Non-Swaged Heater Watt Density Recommendations

                 Block Temperature in °F

Cartridge Heater Internal Thermocouples Types

One optional feature on cartridge heaters are built in thermocouples.

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• Built-in thermocouples can be of type “J” or type “K”, grounded or ungrounded and attached either at the disc end of middle of the cartridge.
• Internal thermocouples are available in a variety of styles, locations and types for your cartridge heater.
• Thermocouple lead wire is 24 ga. solid and unless otherwise specified, thermocouple leads are the same length as the power leads.

When ordering, please specify type, location, grounded or ungrounded (if not specified, you will receive grounded) and insulation material (if not specified, you will receive fiberglass).