7 VG9H 70 en
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NELES VALVGUARD VG9000H
INTELLIGENT SAFETY SOLENOID WITH
HART COMMUNICATION
1.1
General
This manual incorporates Installation, Maintenance and Oper-
ation Instructions for the Metso’s Neles ValvGuard VG9000H.
The VG9000H may be used with either cylinder or diaphragm
type pneumatic actuators for rotary or linear valves.
1.2
Technical description of VG9000H
Neles ValvGuard VG9000H is a 4–20 mA loop-powered
microcontroller-based intelligent safety solenoid and par-
tial stroke test device with HART communication. Device is
suitable to be used in safety related application up to and
including SIL 3 acc. to IEC 61508.
See Safety Manual for functional safety figures and other
safety related details.
The device safety position is 6.0 mA or below. When VG9_L3
version is used, the safety position is 10.0 mA or below. The
device stays alive even at 3.7 mA input signal (at 7.7 mA
when VG9_L3 is used) and communicates via HART.
Optional Remote Communication Interface RCI9H2 is
required if the safety system output is binary (DO) 24 V DC.
See separate RCI9H2 technical bulletin (9RCI21EN) for
detailed instructions.
Main components of ValvGuard are spool valve (SV), pre-
stage unit (PR) and micro controller (μC). Spool valve and
prestage unit are the only components, which takes part of
the safety action. Spool valve controls the main airflow
between supply- (S), actuator- (C1, C2) and exhaust (EXH)
connections. The spool is operated by spring force to fail
safe position and by pneumatic force generated by the pre-
stage valve to the normal position. The prestage valve is
coil operated flapper valve (normally open). Coil of the pre-
stage is energized with the safety control part and it is con-
trolled by the micro controller. Micro controller cannot
prevent the safety action. Pressure sensors (Px) and position
sensor (α) are used to getting the measurements for con-
trolling the PST and other tests. Measurements from the
sensors are used for the device diagnostics.
The VG9000H contains a Local User Interface enabling local
configuration. A PC with Metso Valve Manager
TM
software
together with Metso's FieldCare or any other FDT frame soft-
ware can be used for advanced configuration and diagnostics.
The powerful 32-bit microcontroller controls the valve posi-
tion during partial stroke and other special testing. The
measurements include:
Input signal
Valve position with contactless sensor
Actuator pressures, 2 independent measurements
Supply pressure
Device temperature
Housing pressure
Advanced self-diagnostics guarantees that all measure-
ments operate correctly. Failure of any measurement does
not cause the valve to go to fail-safe position. After connec-
tions of electric signal and pneumatic supply the micro con-
troller (μC) reads the input signal, position sensor (α) and
pressure sensors (Ps, P1, P2 and P3). This information is used
to run the partial stroke tests and other tests.
1.2.1
Technical description of VG9000H_P
Neles ValvGuard VG9000H with P-option (VG9000H_P) is a
4–20 mA loop-powered microcontroller-based partial
stroke test device with HART communication. This device is
for partial stroke test (PST) only and must be used together
with an additional solenoid valve for the safety action.
The prestage valve of the device is coil operated flapper
valve (normally open). Coil of the prestage is normally de-
energized and it is controlled by the micro controller for
testing and calibration. Signal failure does not affect to the
valve position.
NOTE:
The selection and use of the ValvGuard in a specific appli-
cation requires close consideration of detailed aspects.
Due to the nature of the product, this manual cannot
cover all the likely situations that may occur when install-
ing, using or servicing the ValvGuard.
If you are uncertain about the use of the controller or its
suitability for your intended use, please contact local
Metso office for more information.
NOTE:
HART communication can be used for informational pur-
poses, but is not safety certified for diagnostic annunciation.
NOTE:
RCI9H2 includes the Ex-isolator, so there is no need for
separate Ex-isolator in intrinsically safe installations.
NOTE:
Micro controller is only able to control the prestage if
safety control part is energized. Micro controller can never
prevent the safety action to happen since safety action is
the same as there’s no voltage in the safety control part.
Fig. 1
The principle of operation
NOTE:
VG9000H_P version has fundamentally different function-
ality to other VG9000H versions. This version can be iden-
tified by the green cover.
