Frequently Asked Questions

Tel: +44 (0) 7837 337570

The Limpet Heating Company Ltd

Innovative Process Heating Solutions for Industry

Frequently Asked Questions

Q. When will the CATTS process pipe heating system be available?

A. We are now at an advanced stage in the development of the system. Trials are being undertaken on the new printed circuit boards and the design of the Limpet heater body is virtually complete. We have also gone out to suppliers for quotes on extrusion dies and components. We a planning to launch by Q3 2020.

Q. What temperature range will the Limpet provide?

A. Those with electronics inside the case can operate from 0°C up to 80°C. However, if you use a model without internal electronic controls, some can heat up to 250°C.  We have a variety of methods of controlling this. 

Q. How energy efficient is it?

A. Most of the electrical energy is converted into heat. However, the efficiency of the heat transfer depends upon two main factors:

  • The tightness of the bond between the Limpet, the adaptor block (if provided) and the work-piece. We usually provide the Limpet with stainless steel straps that hold the heater (and adaptor block) tightly to the work-piece so as to ensure good heat conduction.
  • The effectiveness of the insulation provided around the work-piece and the Limpet heater. Good insulation is essential and will result in a highly efficient heating system.

Q. How do I know if the Limpet is working?

A. There is an indication light on the end of the AlphaLimpet and if you have a version with a supervisory port, you will also be able to see whether the system is working. Provided power is still available, the AlphaLimpet will also produce an alarm in the event of failure of the heating element.

Q. How do I know if the Limpet isn't working?

A. See above. Also, it won’t get hot!

Q. Do I need to use insulation?

A. Yes. You will increase the system efficiency by several orders of magnitude by using effective insulation. See efficiency above.

Q. What supply voltage / power supply is required?

A. Either 110Vac or 230Vac.

Q. What IP rating is it?

A. IP67, which means that the Limpet can be submerged in 1 metre of water for up to 30 minutes but should not be high pressure-washed.

Q. Why is it better/different to trace heating or water jacket heating?

A. Every heating system has its strengths and weaknesses. The Limpet heating system is designed primarily for installation on work-pieces that are difficult or expensive to heat using other means.  The main benefit of the Limpet is that you will know immediately if there is a failure. However, it is designed using components that have proven and very long MTBFs, so it is very reliable.

Because it is an electrical system, it cannot contaminate the product that is being heated.

Q. How easy is it to change temperature settings?

A. This is very easy with the AlphaLimpet. You unscrew the top plate and then adjust the two dials inside to whatever temperature you require up to 80°C. You then replace and secure the top plate which will restore the IP67 rating. Other models have either dial temperature control or can be connected to different temperature ranges in a small, separate junction box.

Q. Can I program the Limpet to switch on automatically in a frost-protection application?

A. Yes. If you use a version with an external temperature sensor (located outside the insulation), you can program the Limpet to switch on automatically when the ambient temperature falls below a certain temperature (e.g., 5°C). You can also adjust the operating temperature to whatever you want (say 20°C for a frost-protection application).

Q. Is there a danger of electrocution when I adjust the temperature or program, the Limpet?

A. No. Of course you should disconnect the Limpet before opening it but even if you did not, the leads on the circuit board around the opening operate at only 5Vdc. Some models (e.g., the MicroLimpet) are filled with potting compound, so the electrics are completely inaccessible.

Q. How accurate is the set-point temperature?

A. The set point on the AlphaLimpet is accurate to within 0.8°C. However, the actual heat in the work-piece will vary depending upon the proximity to the heater. If good insulation is provided around the work piece and a temperature sensor is located in a position that provides a good average temperature reference, then you should be able to control the temperature of the work-piece quite accurately.  The accuracy of other models varies. See the specifications here >>>.

Q. How quickly does the Limpet heat up?

A. Limpets heat up within a few minutes, depending upon the set temperature. However, if you need the unit to warm up more slowly, you can control the ramp rate using the internal programmer. Nevertheless, if the workpiece has a large thermal mass and is not already heated by the fluid passing through it, it may take several hours to reach the desired operating temperature. Again, effective insulation is essential.

Q. How will I know how to program the Limpet?

A. The unit is supplied with a comprehensive set of programming instructions.

Q. Is the Limpet easy to remove for maintenance of the work-piece?

A. Yes. This is simply a case of switching off or disconnecting the unit and undoing the steel straps or bolts securing the Limpet to the work-piece. If cables or junction boxes are strapped to the work-piece, then it may be necessary to remove these as well.

Q. What maintenance does the Limpet need?

A. None.   

Q. What is the lifetime of the Limpet?

A. Components used within the system are rated at 30% or more below their maximum operating parameters, even when running at full power.  For most applications, the system only runs at full power for the first 2 or 3 minutes, after which it will settle down to approximately 50% usage.  This gives the system a very long lifetime, way beyond the normal MTBF times of the regular components within it.

Q. What sort of electrical connections do I need for the Limpet system?

A. You will require an electrical mains supply at 110Vac or 230Vac.  We offer three options:

  • Mains cables (if necessary with standard mains plugs) that run into IP68 rated M16 glands on the Limpet. There are various cable options available, depending upon the application and temperature requirements. 
  • Armoured cable conduit (normally M16). In this instance the Limpet is supplied with up to 3m of electrical cable and supervisory cable (for certain models) on the input side and in some models with the same on the output end.  Conduit is also supplied loose, as necessary. Having cut the conduit to the desired length, you can then insert the cables and connect the conduit into the Limpet and one or more junction boxes (which we can provide upon request as part of the kit) using the IP67 glands provided.
  • Cables with IP67 rated Phoenix or Molex connectors for both power (M16) and supervision (M8) with up to two connections at each end of the Limpet, depending upon the model chosen.

Q. Do I have to buy an adaptor block?

A. This depends upon the shape of the work-piece. If it is not flat, then it will be necessary either to use an adaptor block that is profiled to fit the work-piece or to modify the work-piece so that it has a flat platform onto which the Limpet can be mounted.

                                                             Tel: +44(0)7837 337570 or +44 (0)7710 009500    e-mail:

The Limpet Heating Company Limited

Registered Office: 9 Thorne Road, Doncaster, South Yorkshire, DN1 2HJ, United Kingdom

Company No: 08721292;  VAT No: 173 6814 88