KROHNE DK 32-DK 34-DK 37 EN - Manual (Page 36)

7
TECHNICAL DATA
36
DK32 - DK34 - DK37
www.krohne.com 06/2014 - 4000287103 MA DK32-34-37-R05-en
7.5 Differential pressure regulators
Differential pressure regulators are used (DK32 and DK37 only) to help maintain constant flow
rates in the case of fluctuating inlet or outlet pressures. Minimum pressure levels are required
to permit operation of the regulators (see Regulator characteristics).
Differential pressure regulators are not pressure reducing valves!
1 Inlet pressure regulators, types RE, NRE
The regulators maintain a constant flow rate at variable inlet pressure and constant outlet
pressure.
2 Outlet pressure regulators types RA, NRA
The regulators maintain a constant flow rate at constant inlet pressure and variable outlet
pressure.
In order to function, there must be pressure difference between the inlet pressure and
the outlet pressure. The inlet pressure p1 must always be greater than the outlet pressure p2.
Regulator characteristics
Example: Inlet pressure regulator RE-1000: Current flow rate: 1000 l/h air
Constant outlet pressure
p2:
1.013 bar abs.
With a variable inlet pressure greater than 0.5 bar the flow rate in the device is constant.
Example: Outlet pressure regulator NRA-
800
Current flow rate: 800 l/h air
Constant inlet pressure: 6 bar
With a variable outlet pressure of 0...5.5 bar the flowrate in the device remains constant.
1 Inlet pressure regulators, types RE and
NRE 2 Outlet pressure regulators, types RA and
NRA
MA_DK32_34_37_R05_en_287103_PRT.book Page 36 Friday, June 6, 2014 11:42 AM