16
EB 3128 EN
Design and principle of operation
The minimum required differential pressure
Δp
min
across the valve is calculated as follows:
Δp
min
=
Δp
restriction
+
(
V
)
2
K
VS
·
Δp
min
Minimum differential pressure in bar across the valve
Δp
restriction
Differential pressure created at the restriction for measuring the flow rate
V
·
Adjusted flow rate in m³/h
K
VS
Valve flow coefficient in m³/h
Table 2:
Materials
Body
Red brass CC499K (Rg 5) · Spheroidal graphite iron EN-GJS-400-18-LT
1)
Seat
Stainless steel 1.4305
Plug
PN 25
Brass (resistant to dezincification) with EPDM
2)
soft seal
PN 16
Brass, resistant to dezincification and plastic with EPDM soft seal
Diaphragm
case
PN 25
Red brass CC499K (Rg 5) · Spheroidal graphite iron EN-GJS-400-18-LT
1)
PN 16
Stainless steel 1.4301
Valve spring
Stainless steel 1.4310
Restriction
Brass, free of dezincification
Operating diaphragm
EPDM
2)
with fabric reinforcement
Seals
EPDM
2)
1)
Additional version in DN 32, 40 and 50: valve with flanged body made of spheroidal graphite
iron
2)
Special version in PN 25, e.g. for mineral oils: FKM
