Swaged Cartridge Heaters (HotRods)

• Swaged in leads are ideal for applications where there is a lot of movement or the leads must be bent sharp upon exiting the heater.
• Please note that for heaters over 3" long there is a short unheated section where the leads connect to the power pins. 
• Also remember that if the heater is inserted completely into the hole, the leads are exposed to the block temperature (maximum temperature for standard leads is 550°C, 1022°F). 
• Unless otherwise specified, all heaters are supplied with swaged in leads. Standard lead wire type is Duraflex wire, rated to 550C. Other lead wire types are available.

• Crimped on leads are generally used where the temperature at the end of the heater exceeds the maximum rated temperature of the lead wire. Since the connection between the leads and power pins is made outside the heater, the unheated length at the lead end of the heater is kept to a minimum.
• Crimped on leads are not recommended for applications where the leads must be bent sharply near the heater, or in applications where the leads will be subject to a lot of flexing.
• The high temperature connectors are covered by 1-1/2" of 2500 volt silicone rubber coated fiberglass sleeving.

• Post terminals (also called screw terminals or stud terminals are used in applications where easy lead replacement is desirable. They work great with ring terminals or fork terminals.
• Post terminals are only available on 1/2" diameter heaters and larger.
• Terminals are #6-32 and supplied with 2 stainless steel washers and 2 stainless steel nuts on each end. Other sizes are available.

• 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 seal has a temperature rating of 350°F, it softens slightly above 300°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.

• 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 500ºF and while extremely flexible, it is not as strong mechanically as other options.
• Although the RTV is rated for 500ºF, silicone rubber leads are only rated to 392ºF. An option is to use Duraflex lead wire instead. Duraflex is rated to 1000ºF 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.

• Standard flange material is stainless steel.
• 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.
• Flanges also assist in heater removal. 
• Flanges can be round or irregularly shaped and are 1/16" thick. 
• Custom round or rectangular flanges available.
• Contact Backer Marathon for standard and non-standard flange configurations at sales@backermarathon.com.

Mechanical Stops are ideal for preventing heaters from sliding too far into the hole. Backer Marathon offers the following mechanical stops:

• Weld Beads
• Tab Stops
• Locating Rings

• Right angle leads are ideal for applications where space is limited.
• Leads are covered with silicon impregnated fiberglass sleeve where they exit the heater.
• When ordering, please specify the overall length.

• Right angle stainless steel braid offers the same advantages as swaged in stainless steel braid, but allows use in tight spaces. 
• When ordering, please specify the overall length.

• Right angle stainless steel conduit offers the advantages as swaged in stainless steel conduit but allows use in tight spaces.
• When ordering, please specify the overall length.

• Right angle flexible conduit can also be attached to the sheath with a copper elbow
• This method can also be used to attach right angle flexible conduit to stock heaters.
• Order length = Insertion Length + "A" Dimension

• Flexible conduit can also be attached to the sheath with a copper coupler.
• This method can also be used to attach flexible conduit to stock heaters.
• Order Length = Insertion Length + "A" Length                     

• Cartridge heaters can be bent at any angle from 10° to 120°.
• Heaters must be bent in an unheated section.
• Can be constructed with most of the other available options.

• Swaged in stainless steel braid provides excellent abrasion protection while allowing the leads to be bent in a tight radius.
• Because the braid is swaged in, it is extremely resistant to pulling out of the heater.

• Flexible conduit (also known as armor or hose) provides maximum lead protection from abrasion but cannot be bent quite as sharply as stainless steel braid.
• Flexible conduit is swaged into the heater for maximum protection.

• Convoluted Conduit is not a seal at all, but rather a sealed, stainless steel, flexible hose brazed to the heating element. This protects the lead and covers the end of the heater. It is rated for applications up to 1100°F. 
• Unlike standard conduit, Convoluted Conduit is sealed and provides complete water resistance at any temperature while forming a positive seal against contamination entering the heater.
• While the hose is flexible, it is not recommended for applications with continuous flexing and movement. It is best used in applications where moisture or contamination is an issue.
• It is available only on heaters 1/2" diameter and larger.
• It is available on standard 5/8" diameter cartridge heaters, 3/4" diameter cartridge heaters and Gala style heaters. In most cases, Convoluted Conduit is brazed directly to the heater.

Cutaway photo of convoluted conduit.