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Valtek ShearStream SB Ball Valves VLENDS4152-00-A4 05/15
3.6
Connection of the Shearstream SB Ball Valve to the SIS Logic Solver
The Shearstream SB Valve should be assembled with an actuator and logic solver where all components are safety rated.
The safety rated logic solver shall actively perform the safety function as well as automatic diagnostics (if any) designed
to diagnose potentially dangerous failures within the Shearstream SB Ball Valve, (i.e. partial valve stroke test).
3.7
General Requirements
The system and function response time shall be less than the process safety time. The Shearstream SB Ball Valve will
move to its defined safe state in less than this time with relation to the specific hazard scenario.
All SIS components including the Shearstream SB Ball Valve must be operational before process start-up.
The User shall verify that the Shearstream SB Ball Valve is suitable for use in safety applications by confirming the
Shearstream SB Ball Valve nameplate and model number is properly marked.
Personnel performing maintenance and testing on the Shearstream SB Ball Valve shall first be assessed as being competent
to do so.
Results from periodic proof tests and partial valve stroke tests (if any) shall be recorded and periodically reviewed.
The Shearstream SB Ball Valve shall not be operated beyond the useful lifetime as listed in paragraph 5.3 without undergoing
overhaul or replacement.
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Installation & Commissioning
4.1
Installation
The Shearstream SB Ball Valve must be installed per the standard practices outlined in the Maintenance and Installation
Instructions.
The environment must be checked to verify that environmental conditions do not exceed the ratings.
The Shearstream SB Ball Valve must be accessible for physical inspection.
4.2
Physical location and placement
The Shearstream SB Ball Valve shall be accessible with sufficient room for pneumatic connections to the actuator and
shall allow for manual proof testing to take place.
The Shearstream SB Ball Valve shall be mounted in a low vibration environment. If excessive vibration can be expected
then special precautions shall be taken to ensure the integrity of pneumatic connectors or the vibration should be reduced
using appropriate damping mounts.
4.3
Pneumatic Connections
Pneumatic piping to the valve actuator shall be kept as short and straight as possible to minimize airflow restrictions and
potential clogging. Long or kinked pneumatic tubes may also increase valve closure time.
Only dry instrument air filtered to 50 micron level or better shall be used.
The process air pressure shall meet the requirements set forth in the actuator installation manual.
The process air capacity shall be sufficient to move the valve within the required time.
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Operation & Maintenance
5.1
Proof Test requirement
During operation, a low demand mode SIF must be proof tested. The objective of proof testing is to detect failures within
the equipment in the SIF that are not detected by any automatic diagnostics of the system. Of main concern are undetected
failures that prevent the SIF from performing its function.
Periodic proof tests shall take place at the frequency (or interval) defined by a SIL verification calculation. The proof tests
must be performed more frequently than (or as frequently as) specified in the SIL verification calculation in order to
maintain the required safety integrity of the overall SIF. Results from periodic proof tests and partial valve stroke tests (if
any) shall be recorded and periodically reviewed.
For detailed Proof Test information refer to the FMEDA report for the Shearstream SB Ball Valve.
5.2
Repair and replacement
Repair procedures outlined in the Maintenance and Installation Instructions must be followed.
