ARI Armaturen STEVI 451 EN - Manual (Page 3)

Rev. 0040306000 0410 Page 3
Operating and installation instructions
3-way control valves - STEVI
®
450 / 451
4.0 Description
4.1 Scope of applications
Valves are used for „controlling the flow of liquids, gases and vapours in chemical and other
processing plants and for plant engineering“.
The information complies to the Pressure Equipment Directive 97/23/EC.
It is the responsibility of the machine planner to ensure compliance.
The special markings on the valve must be taken into account.
Refer to the catalogue sheet to see which materials are used in standard versions.
Please contact the supplier or the manufacturer if you have any questions.
4.2 Operating principles
ARI control valves are especially suitable for actuation by pneumatic or electrical actuators.
Depending on the mode of operation, two different execution methods are possible:
1. Execution with mixing plug
2. Execution with diverting plug
The execution with the mixing plug is the standard execution method.
This execution method is to be chosen when the valve is also employed as a mixer
(2 entrances, 1 exit).
In exceptional cases, the execution with the mixing plug can also be employed as a
diverting plug (1 entrance, 2 exits). This requires, however, low differential pressures and
stable propulsion.
The execution method with the diverting plug is only to be employed with the operation of
diverting.
Explanation:
ATTENTION !
- Refer to the data sheet for applications, limits on use and possibilities.
- Certain media require or preclude the use of special materials.
- The valves are designed for standard operating conditions. If conditions exceed
these requirements, e.g. aggressive or abrasive media, the operator should
state the higher requirements when ordering.
- Valves made from grey cast iron are not authorised for use in systems subject
to TRD 110.
Mixing operation Diverting operation
AB A
B
AB A
B