Burkert Type S020 - Manual (Page 20)

20
Technicaldata
Type S020
6.4. K factors
6.4.1. Terms of reference
The K factors have all been determined under the following terms
of reference: fluid = water, water and room temperatures of 20°C,
minimum upstream and downstream distances respected, appro-
priate pipe dimensions.
6.4.2. calculation of K factors (in pulse/
litre) for saddles, fusion spigots,
welding sockets with radius or
screw-ons
The calculation does not apply to T fittings or welding
sockets for measuring devices with a clamp connection.
In addition to the terms of reference mentioned above, the K factors
for saddles, fusion spigots, welding sockets with radius and screw-
ons have been determined as a function of the external diameter
(d
material
) and the wall thickness (s
material
) of the pipe given in the
tables.
→
When the dimensions of the pipe are slightly different from
dimensions d and s given in the tables, recalculate the K factor
using one of the following formulae:
These formulae can only be applied if the dimensions of the
pipe vary by +/-5% compared with the theoretical dimen-
sions given in the tables.
K
n
= K
t
x
d
t
2
d
n
2
Fig. 3: Fitting used with a paddle-wheel flowmeter
K
n
= K
t
x
d
t
2
d
n
2
Fig. 4: Fitting used with an electromagnetic flowmeter
K
n
= recalculated K factor
K
t
= K factor given in the table
d
t
= D
material
- 2s
material
= theoretical internal diameter of the pipe
calculated using the values D
material
and
s
material
given in the tables, for each fitting
material (D
material
= external diameter of
the pipe and s
material
= thickness of the
pipe)
d
n
= internal diameter of the pipe
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