6 Measuring the boiler
6.5 Boiler analysis: Fuel
The seal of quality of the Pellet Association (PVD/PVA) and DIN CERTCO certification offer effective assurance that
you have received quality pellets. However we always recommend that you perform several simple tests when
pellets are delivered. These are simple tests that anyone can perform, although some of these tests are quite
subjective.
• Visual inspection of condition and size:
Only a small proportion of dust and abraded particles should be contained. The prescribed pellet diameter
is 6 mm. The majority of pellets should be 20 mm in length (10 to 35 mm), individual pellets to 45 mm in
length can be included. Pellets that are too long can cause blockages in systems with type GL and GS fuel
extractors.
• Visual inspection of surface and colour:
The pellets should have a smooth, shiny surface that is free of transverse or longitudinal cracks. They should
have the colour of wood chips, or they should only be slightly darker. Often pellets that are too dark are too
hard. Also pellets that are too dark can have excessive bark content.
• Rubbing test:
Take a handful of pellets and rub them between your hands with moderate pressure for 2 - 3 s; there should
only be a few abraded particles.
• Pulling test:
Hold a single pellet on both ends and pull it without twisting it or bending it. The pellet should yield to the
pulling force and break apart. This means that expenditure of force is required to pull the pellet apart: however
you should be able to pull the pellet apart.
• Float test:
The pellets should sink in clean, cold water. If you leave them in water, after approximately 20 - 30 sec.
a dissolving process starts, which is concluded after 2 - 3 min.
The following always applies:
Obtain a guarantee of pellet quality from your supplier.
The quality is more important than the price!
MA-Easyfire 10.2008_EN.indd 68MA-Easyfire 10.2008_EN.indd 68 30.03.2009 13:30:10 Uhr30.03.2009 13:30:10 Uhr
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