These valves are no shut-off elements ensuring a tight closing of the valve. In accordance
with DIN EN 60534-4 and/or ANSI FCI 70-2 they may feature a leakage rate in closed posi-
tion in compliance with the leakage classes II – V:
Leakage class II (metal sealing double seat cone) = 0.5% Kvs value
Leakage class III (metal sealing cone) = 0.1 % Kvs value
Leakage class IV (PTFE seal cone) = 0.01 % Kvs value
Leakage class V (soft seal cone) = 1.8 x 10-5 x Δp x D* [l/h]
*D=seat diameter
Consequently, according to DIN EN ISO 2503 and DIN EN ISO 7291, a safety valve has to
be installed on the control side, which is dimensioned and adjusted in such a way that the
lower one of both pressure indications as mentioned below is relevant as response pressure:
- 1.5 times the maximum set pressure and/or (P out) of the valve (see nameplate),
whichever is the lowest
- PS out (see nameplate)
The response pressure of the safety valve should be abt. 40 % above the max. set pressu-
re of the pressure control valve.
Contrarily to the Pressure Equipment Directive, Annex 1, Paragraph 7.3, the short-term ma-
ximum excess pressure is limited to 5 % of the max. allowable pressure (see above).
Failure to observe this regulation means danger to life and limb and may cause da-
mage to the pressure-regulating valve.
Pressure-regulating valves are generally supplied with an open spring cap to facilitate
maintenance.
Valves with a sealed spring cap and leakage line connection can be supplied for toxic or
hazardous media. In this case the user must make sure that a suitable leakage line is installed.
MANKENBERG valves are supplied as standard for screw-mounted or flange-mounted pipeline/tank
connections – also for special connections if required.
The upper limit of the permitted operating data for pressure and temperature is permanently
marked on each fitting supplied.
Each fitting bears the following markings as a minimum:
The markings (in the case of fittings made of deep-drawn stainless steel, they are etched into the body)
should neither be covered nor painted over, so that the fitting remains identifiable.
Pressure-reducing valve+ type or
backpressure regulator + type or
differential pressure control +type
or flow control valve + type or
vacuum control valve + type
See Section 11 <Further information> for the address
Design name as per accompanying MANKENBERG data
sheet.
e.g. DN or G and numerical value
PN or Class and numerical value
Numerical value for DN in [mm], for G in [inches]
Numerical value for PN in [bar], for Class in [lbs/square
inch]
Unless otherwise indicated, all data give the overpressure
above atmospheric. If 2 numerical values are given, these
apply to the inlet and outlet pressure.
Pressure range and numerical
values
Temperature and numerical
value
Temperatures above 50 °C entail a reduced pressure resis-
tance. This must be considered for the corresponding ma-
terial in accordance with the DIN EN 1092 standard
CrNiMo steel = high-alloy austenitic steel
e.g.
Ex II 2G IIB TX -10°C<Ta<+80°C
only for devices with conformity certification according to
ATEX
danger of
fatalities
caution
