RE 521, RE 551 PLUS, RE 581, RE 581 PLUS
English
43
N Turn the screw (1)
counterclockwise until the shroud
can be swung upward
N Pull the grip (2) in the direction of
the arrow to open the shroud
RE 551 and RE 581 only
Under normal operating conditions it is
not necessary to descale the machine if
STIHL scale inhibitor is used
consistently STIHL scale inhibitor is
specially designed for
STIHL detergents.
Mixing STIHL scale inhibitor with water
N Measure the water hardness or
contact your water supply company
to establish the water hardness
range
Depending on water hardness – see
table:
N Mix scale inhibitor at a ratio of A : B
with clean water – maximum
capacity of the storage tank = 1 l
– A = scale inhibitor
– B=water
RE 551
RE 581
Open shroud Add scale inhibitor
Unit water
hardness
Hardness
range
Mixing ratio
(A : B)
°dH < = 12 1 : 2
> 12 undiluted
°e < = 15 1 : 2
> 15 undiluted
°f < = 21.4 1 : 2
> 21.4 undiluted
ppm CaCO
3
< = 214 1 : 2
> 214 undiluted
mval/l < = 4.28 1 : 2
> 4.28 undiluted
mmol/l < = 2.14 1 : 2
> 2.14 undiluted
Unit water
hardness
Hardness
range
Mixing ratio
°dH < = 12 1 : 1
> 12 undiluted
°e < = 15 1 : 1
> 15 undiluted
°f < = 21.4 1 : 1
> 21.4 undiluted
ppm CaCO
3
< = 214 1 : 1
> 214 undiluted
mval/l < = 4.28 1 : 1
> 4.28 undiluted
mmol/l < = 2.14 1 : 1
> 2.14 undiluted