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Non-Swaged Cartridge Heaters

Non-swaged cartridge heaters offer a cost effective solution where the performance of a swaged cartridge heater is not required. Non-swaged cartridge heaters can be used at watt densities up to 45 watts per square inch and temperatures up to 1000°F. Non-swaged cartridge heaters offer tighter length tolerances than swaged heaters and can be built with 3 independent heat zones. Non-swaged heaters are not recommended for applications where there is a lot of vibration or impact.

Construction

Specifications

Applications

Fittings

End Seal Options

Other Options

Watt Density

Construction

Standard leads are UL rated to 550°C (1022°F) and are connected internally with nickel connectors.
High temperature cement filling protects leads and internal parts. Epoxy and silicone rubber leads are available.
Nickel-Chromium resistance wire stretched evenly throughout the length for even heat distribution.
High purity MgO is vibratory filled into the heater for maximum heat transfer.
304 Stainless Steel sheath for superior oxidation resistance.
Welded end disc to prevent contamination and moisture absorption.

Specifications

Nominal Diameter	Minimum Diameter	Maximum Diameter	Std. Lead Wire Gauge	Max Amps with Std. Lead Wire	Max Lead Wire Gauge	Maximum Amps	Maximum Volts
3/8″	.365	.375	22	9	18	15	300
1/2″	.490	.500	22	9	18	15	480
5/8″	.615	.625	18	9	16	25	600
3/4″	.740	.750	18	15	16	20	600
1″	.990	1.000	18	15	16	20	600

Applications

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 are not recommended for applications where there is is a lot of vibration or impact.

Fittings

Most of the lead configurations and options available for swaged HotRod heaters are also available for non-swaged cartridge heaters. Our standard options are listed below. If you don’t see what you need, consult your MPI Morheat agent for more information or contact us at sales@mpimorheat.com.

Flanges

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.

Standard Flange Dimensions

Flange Outside Diameter	1″	1-1/2″	2″
Can be used on	5/16, 3/8, 1/2	5/16, 3/8, 1/2, 5/8, 3/4	1/2, 5/8, 3/4, 1
Hole Spacing	3/4	1-1/18	1-1/2
Hole Size	.14	.16	.20

Single Ended NPT Fittings

Single End NPT Fitting Specification Chart

Heater Diameter	3/8″	1/2″	5/8″	3/4″	1″
NPT Thread Size	1/4	3/8	1/2	3/4	1
Brass “A”	.70	.74	.80	.92	1.30
Brass “B”	.56	.69	.87	1.06	1.44
Stainless Steel “A”	.76	.77	.84	.96	1.27
Stainless Steel “B”	.56	.67	.87	1.06	1.37

Double Ended NPT Fittings

Double Ended NPT Fitting Specification Chart

Heater Diameter	3/8″	1/2″	5/8″	3/4″	1″
NPT Thread Size	1/4	3/8	1/2	3/4	1
Brass “A”	1.13	1.25	1.53	1.72	2.35
Brass “B”	.56	.69	.87	1.06	1.37
Stainless Steel “A”	1.13	1.25	1.53	1.72	CALL
Stainless Steel “B”	.56	.68	.87	1.06	CALL

Mechanical Stops

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

Custom Fittings

Non-Swag Heater with Stainless Steel NPT Straight Threads

Straight Threads
Brass Cubes
Stainless Steel Cubes
Others to Your Specifications

End Seal Options

End Seals

Cement	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. Up to 2600°F.
Epoxy Potting	Provides a very good seal with excellent mechanical strength. However, it’s adherence to Teflon or silicone rubber lead wire is only fair. It is rated up to 265°F and bonds well to Duraflex lead wire.
Epoxylite Potting	Provides similar mechanical properties as epoxy potting. Up to 600°F.
RTV	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.

Chart

End Seal Type	Max Temp	Moisture Protection	Contamination	Mechanical Strength	Vibration Resistance	Moisture Applications	Vibration or Flexing
Cement Potting	2600°F	Poor	Fair	Good	Poor	Poor	Poor
Epoxylite Potting	600°F	Fair	Very Good	Very Good	Excellent	Good	Excellent
RTV w/ Silicone Rubber Leads	392°F	Excellent	Excellent	Fair	Good	Excellent	Average
Epoxy Potting	265°F	Good	Good	Excellent	Excellent	Good	Good

Other Options

Distributed Wattage

Distributed wattage heaters are often used in platens and sealing bars. Wattage is usually increased on the ends of the heater to compensate for end losses and maintain a constant temperature along the heated product.
Specify desired lengths in inches and wattages in percentage.

Dual Voltage

Dual Voltage cartridge heaters can be engineered to operate at different voltage ratings. To order, specify dual voltage and voltage requirements.

Multi-Zone

Individually controlled heat zones give flexibility when needing to control the heat along the length of a cartridge heater. These zones are commonly used in platen applications where tight temperature tolerances are important.
Three Zone heaters are constructed with (6) color coded leads. Yellow leads indicate disk end zone. Black leads indicate center zone. Red leads indicate lead end zone. Please consult factory for available diameters. Specify length and wattages of desired zones.
Dual Zone heaters are commonly constructed with 4 power leads.

Three Phase

MPI Morheat Cartridge Heaters are available for three phase delta for high amperage applications. Certain restrictions apply.

Watt Density

Formula

Watt density is calculated with the following formula:

Watt Density = Wattage / Heated Length x Diameter x 3.14

Clearance

Clearance is determined by taking the hole diameter and subtracting the heater diameter.

Cycling reduces heater life and high cycling applications should use lower numbers.
Staying below these values will result in increased heater life.

Max Watt Density

Hole Clearance	1000*	800*	600*	400*	200*
0.003	25	30	35	40	45
0.005	20	25	30	35	45
0.010	20	23	28	30	38
0.015	18	20	25	27	34
0.030	16	15	20	23	30
0.100	10	12	15	20	25