Cartridge Heaters

Cartridge Heaters (PDF datasheet)

Cartridge heater connection and lead options

Standard cartridge heater easy reference table (Web datasheet)

Standard heat distribution

Unheated zone on connection side and/or far end

Version 1 (2 switchable zones / 3 connection leads)

Version 2 (2 switchable zones / 4 connection leads)

General information

All HLP type heaters can be supplied with an integrated thermocouple. Heaters mentioned in the table are available ex-stock. High performance cartridge heaters are especially suitable for internally heated nozzles and heated torpedos where, due to space considerations, a separate thermocouple cannot be installed. The thermocouple is fixed in position, compacted and potential free insulated from the sheath or alternatively connected with the heater sheath.

General information

All HLP type heaters can be manufactured with an integrated temperature sensor i.a.w. DIN EN 60751 (PT 100) or with an integrated NTC-sensor (negative temperature coefficient) for precise temperature measurement. Typical fields of application therefore are within the car industry, electrodomestical appliances, air conditioning devices, for general machinery and medical technique appliances.

Characteristics

The lightly compacted cartridge heaters of this series distinguish themselves by a higher immunity against mechanical shock, and by a substantially longer useful life as compared with noncompacted metal sheathed cartridge heaters of the same surface load. They are suitable for heating liquids, gaseous and solid media and resist arduous service conditions in industrial applications.

Characteristics

The high performance cartidge heater type HLPK has a conically tapered sheath with a taper ratio 1:50 i.a.w. DIN 1 for standard taper pins. The conical shape of the cartridge heater guarantees an exact force fit in the workpiece. In the case of accurately reamed bores, there is an excellent fit, as the cartridge heater in this case takes a slightly deeper installation depth. An excellent heat distribution results from the exact fit and, thus, the danger of overheating the cartridge heater is kept low. In order to get an even temperature profile, the cartridge heaters type HLPK are equipped with reinforced performance zones on both sides.

General Information

These highly compacted heating elements have been developed primarily for the heating of small parts. The sheath is made of chrome-nickel steel, material no. 1.4541 and serves as a return conductor. Therefore the high performance cartridge heaters type HLP 2.8; HLP 4.5 and HLP 5.0 may only be used for operation at low voltages up to 42 V max.

Function

The self regulating cartridge heater type HLPR is a compacted heating element with PTC-effect (positive temperature coefficient: performance decreases the more that the temperature increases). When the temperature on the sheath of the heater increases, the performance is automatically reduced due to the increasing resistance within the PTC elements. The cartridge heater regulates itself, any additional control equipment is not required.

Function

This self regulating HLPR type heater with a long shaft has been developped especially for the use within radiators.

Advantages

• no switches which are subject to mechanical wear
• the allowable maximum temperatures will not be exceeded at any time due to the physical properties of the PTC-element
• the heaters are not sensitive to variations in voltage they can be run from 200 V through 265 V
• dielectric strength 4000 V

Description

Expansion screws are always used where the tightening of the screw has to assure a long lasting and solid connection. This is mostly used for large electrical machines like turbines and generators or for large diesel engines e.g. for ships. The tightening of the screw serves to assure that the housing halves of the machines are safely fitted and that they can withstand the mechanical load during operation such as vibration or pressure. The screws can also be used for the fixation of the machines to a socket. The use of expansion screws is based on the elongation of the steel shaft within certain limits which is proportional to the applied heat. Expansion screws return back to the same length when cooling down to ambient temperature.

• For cartridge heaters with surface loads up to 20 W/cm2 the receiving hole must be drilled according to ISA H7 with peak to valley height as small as possible.
• For cartridge heaters with surface loads exceeding 20 W/cm2 a press fit is necessary which can be obtained by individual attention beeing paid to each cartridge heater.
• The drilled receiving bores of cartridge heaters must be cylindrical. Crossing bores and shrinkages cause a localisation of heat and shorten the useful life of the heating elements.
• To facilitate the insertion and the removal of the heating elements the receiving bores should be drilled in a continuous motion (to avoid a stepped bore).
• The maximum working temperature of the cartridge heaters stated in the leaflet does not apply to the connection leads. These must be selected according to the operating conditions.
• The lubricant VARYBOND REGULAR GRADE beeing resistant to temperature facilitates the in sertion and removal of the heating elements in bores with small tolerances.
• When using several cartridge heaters the distance between two con - secutive cartridges should be at least equal to the cartridge diameter.
• The end of the cartridge heater with the connection leads should be protected against liquid and pasty media (lubricants, oil, synthetic materials, etc.) as well as their vapours because otherwise leakage currents and, possibly flashover could occur at the outlet connection terminals.