ARI Armaturen STEVI H 488 EN - Manual (Page 3)

Rev. 0040308000 0410 Page 2-3
Operating and installation instructions
3-way/str.thr. control valves - STEVI
®
H 485-488
4.0 Description
4.1 Scope of applications
Valves are used for „controlling the flow of liquids, gases and vapours of fluid group 2 for
heating, ventilation and air conditioning“.
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 servo controlled valves are especially suitable for actuation by electrical actuators.
A parabolic plug is used as a flow restrictor in flow directions A -> AB and AB -> A, and a
slotted plug is used in flow directions B -> AB and AB -> B.
In diverting operation (1 inlet AB, 2 outlets A and B) high actuating forces must be
expected.
Explanation:
When used as a straight through control valve, inlet B is fitted with a dummy flange (refer to
item 7.3).
Please note the arrow on the valve indicating the flow direction.
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