Piazzetta IP 78/68 Instructions For Installation, Use And Maintenance Manual page 11

Pipes and maximum usable lengths
Pipes of painted aluminium-clad steel (minimum thickness 1.5mm),
stainless steel (AISI 316) or enamelled steel (minimum thickness 0.5
mm) with a nominal diameter of 80 or 100 mm (for pipes which run
inside the flue maximum diameter 150 mm) can be used.
The male-female connectors must have a minimum length of 50 mm.
The diameter of the pipes depends on the type of installation. The stove
was designed to take 80 mm diameter pipes but, as shown in Table
1, in some cases the use of double-lined 100 mm diameter pipes is
recommended.
TABLE 1 – PIPE LENGTH
TYPE OF INSTALLATION
Maximum length
(with three 90° bends)
For installations more than
1200 m above sea level
Maximum number of bends
Length of horizontal sections
with minimum 3% gradient
a
Losses in pressure associated with a 90° bend can be compared
to those incurred by one metre of pipe. An inspectable union-
tee can be considered equivalent to a 90° bend.
EXAMPLE: if installing a section greater than 4.5 m in length with
80 mm diameter pipe, calculate the maximum usable length in the
following ways.
• If a maximum of three 90° bends are used, the maximum length of
the section will be 4.5 m.
• If a maximum of two 90° bends are used and bearing in mind that a
90° bend can be replaced by one metre of pipe, the maximum length
of the section will be 4.5 m + 1 m = 5.5 m.
• If a maximum of one 90° bend is used and bearing in mind that a 90°
bend can be replaced by one metre of pipe, the maximum length of
the section will be 4.5 m + 1 m + 1 m = 6.5 m.
Where 100 mm diameter pipe must be used, connect it to the stove flue
outlet with a 80 mm union-tee then use a 80 mm 100 mm adaptor (not
supplied by Piazzetta) (Fig. 19).
Union-tee
The use of this type of fitting must allow for the collection of condensate
mixed with soot, which builds up inside the pipe. It must also permit
periodic cleaning of the flue without the need to disassemble the pipes.
This type of fitting can be bought at Piazzetta retail outlets together with
the pipes.
An example is given below of a flueway connection, which allows
complete cleaning without having to disassemble the pipes (Fig. 20).
WITH 80 mm WITH DOUBLE-
DIAMETER WALLED 100 mm
PIPE DIAMETER PIPE
4.5 m 8 m
- required
3 4
2 m 2 m
H07028420 / DT2000990 – 01
Fig. 19
Ø100mm
Fig. 20
TEE
DIRECTION
OF CLEANING
DIRECTION OF CLEANING
STRAIGHT REDUCER
Ø80>Ø100
Ø80mm
TEE WITH SEALING PLUG
DT2030337-00
INSULATING
MATERIAL
TEE
DIRECTION
OF CLEANING
DT2030338-01
11