Verein Deutscher Ingenieure

Industrial process control - Pneumatic control valves - Interfaces of valves and auxiliary equipment
 N VDI/VDE 3845 BLATT 1

Annotation

This guideline contains specifications relating to uniform interfaces at the elementary functional groups of actuators. These specifications are intended to make possible the assembly of adjoining functional groups from different manufacturers.

Functional groups as defined in this guideline are:

• the valve, which controls or interrupts the flow of materials by adjusting the cross-sectional area,

• the actuator, which effects or controls the reduction in cross-sectional area by means of positioning force and travel, and

• open- and closed-loop control units and signal transmitters to position the actuator, and systems that supply the auxiliary energy.

The recommendations in this guideline are inapplicable where the valve and the actuator form one structural unit such that exact assignment to elementary functional groups is impossible.

Where Standards for the design of the aforementioned interfaces exist, they are listed in Section 2.

The interface described in Section 3.1 for the positioners and/or feedback units, refers to the rotary actuator's free shaft stub. Attachments at this point are common, but due to the variable designs of the interface it cannot be used universally. The specifications in this guideline are meant to allow uniform mounting of any positioner or feedback unit.

Section 3.2 specifies dimensions suitable for the majority of attachments. If large actuators or short actuating times require larger cross-sections, these dimensions may be varied.