INSTALLATION AND THERMAL INSULATION
To obtain a well functioning application, a good insulation is required. As already been mentioned, we compensate the heat loss through the insulation by supplying heat. A poor insulation gives an application with defective function and a bad operating economy. Here are some tips that can improve the insulation.
- The controller of the vents shall be supplied with plastic insulation against openings in the insulation sheath, downward openings in shall be sealed with sealing compound.
- Most of the insulation material is hygroscopic. Insulation material with closed cell structure (foam) is not hygroscopic, but have in general a lower operating temperature, max. +100°C. Therefore choose insulation with closed cell structure if the temperature admits it.
- Conduit entries through the insulation are carried out on the underside of the pipe, if possible, so they are protected against moisture.
- Vents and flanges etc, has a larger diameter than the pipe. Of this reason shall the heating cable be installed with an extra coiling at those and to be extra careful so that the insulation not get thin to give a straight and facilitated outer sheath. Another advantage with extra cables at vents is when these have to be dismounted at leakage and an extended cable must be cut.
Passage for leading-off connection cables to heating cables and transmitters, are best done from the underside of the pipe when risk of moisture penetrating is nearly non-existent.
If the cable of self-limiting type is used the emitted output is reduced if the cable do not have or have poor contact with the object which are to be heated.
Heating cables shall always be covered with aluminium tape or aluminium foil before insulation. This in order to secure the fit-up of the heating cable against the object and to avoid that the heating cable (due to movements in the application and heating cable), is covered with insulation with cable rupture or poor heat transfer as a result.
At applications with self-limiting heating cable the output curves presented for the heating cable presumes that installation is done with aluminium tape or foil.
The insulation around pumps and small vessels must be fixed so that it does not came loose (insulation support is welded on the outside of the tank wall).