Page 52 - Bürkert

Characteristics of a proportional valve Advice for valve sizing

In continuous flow applications, the choice of an appropriate
K 1,0
V valve size is much more important than with on/off valves. The
K
Vs
0,9 optimum size should be selected such that the resulting flow in
0,8 the system is not unnecessarily reduced by the valve. However,
a sufficient part of the pressure drop should be taken across the
0,7 2875
valve even when it is fully opened.
0,6
0,5 Recommended value: ∆p > 25 % of total pressure
valve
0,4 drop within the system
0,3
Otherwise, the ideal, linear valve curve characteristic is changed.
0,2
If the differential pressure (difference between inlet and outlet
0,1 pressure) exceeds half the value of the nominal pressure, the
0,0 characteristics may change.
0 5 10 [V] For that reason take advantage of Bürkert competent engineer-
4 12 20 [mA]
0 10 20 [mA] ing services during the planning phase!

Ordering Chart

Nominal Max. Max. coil Item no.
Port connection Orifice Kv value
[inch] [mm] [m³/h] pressure differential current Brass Stainless steel
[bar(ü)] pressure [bar] [mA]
Type 2875
G 3/8 2 0.12 25 13 750 236 897 236 899
G 3/8 3 0.25 10 5 750 236 901 236 903

G 3/8 4 0.45 8 4 750 236 905 236 910

G 1/2 6 0.8 4 2 750 236 915 236 919
G 1/2 8 1-Jan 2 1 750 236 922 236 924

Accessories

Description Item no.
Control electronics Type 8605, DIN-Rail version 178 363

Control electronics Type 8605, cable plug with PG-connection 178 354

Control electronics Type 8605, cable plug with M12-connection 178 355
Cable 5 m for Type 8605, M12-connection 918 038

Cable plug Type 2508 008 376
Cable plug Type 2508 with 3 m cable 783 573

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