Bifold SPR12-P1-32-NC-00-BBB-PSV 3/2 Mechanical Valve

SIL Safety Manual
2.1 Safety Function When de-energised (signal removed), the valve moves to its fail-safe position. The valve will operate to
close off the flow path through the valve body, and divert it to tank / exhaust.
The SPR - Pneumatic Spool Valve are designed to be part of a final element subsystem as defined by
IEC61508 and the achieved SIL level of the designed function must be verified by the system designer.
2.2 Environmental Limits The designer of a SIF must verify that the product is rated for use within the expected environmental
limits.
For SIL rated devices the minimum operating temperature is Arctic Service Option to -60°C.
Refer to Bifold Product Catalogue for more information.
2.3 Application Limits The materials of construction are specified in the various Bifold Catalogues and Data Sheets.
Maximum Operating Pressure is up to 10 Bar.
2.4 Design Verification A Failure Mode, Effects, and Diagnostics Analysis (FMEDA) report has been carried out independently
by Exida.com and is available from Bifold on request.
The achieved Safety Integrity Level (SIL) of an entire Safety Instrumented Function (SIF) design must
be verified by the designer via a calculation of PFDaverage considering architecture, proof test interval,
proof test effectiveness, any automatic diagnostics, average repair time and the specific failure rates of
all products included in the SIF. Each subsystem must be checked to assure compliance with minimum
hardware fault tolerance (HFT) requirements.
When using the SPR - Pneumatic Spool Valve in a redundant configuration, a common cause factor of
10% should be included in safety integrity calculations.
The failure rate data listed the FMEDA report is only valid for the useful life time of a valve.
The failure rates will increase sometime after this time period.
Reliability calculations based on the data listed in the FMEDA report for mission times beyond the
lifetime may yield results that are too optimistic, i.e. the calculated Safety Integrity Level will not be
achieved.
Bifold Group Ltd, Head Office, Greenside Way, Middleton, Manchester M24 1SW.
Tel: +44 (0) 161 345 4777 Fax: +44 (0) 161 345 4780 Email: [email protected]
Web: www.bifold.co.uk
Marshalsea Hydraulics Ltd Marshalsea House, Venture Way, Priorswood Industrial Estate,
Taunton, Somerset, TA2 8DE. UK.
Tel: +44 (0) 1823 331081 Fax: +44 (0) 1823 323382 Email: [email protected]
Web: www.bifold.co.uk
USA Office Bifold Fluidpower Ltd 11490 Westheimer, Suite 850, Houston, TX 77077.
Tel: +1 (713) 783 4253 Fax: +1(713) 783 0067 Email: [email protected]
Web: www.bifold.co.uk
Singapore Office Bifold Fluidpower Ltd Toa Payoh Industrial Park, Block 1002, Lorong 8 #07-1475,
Singapore 3109075 Tel: +65 6735 1323 Fax: +65 6735 1367 Email: [email protected]
Web: www.bifold.co.uk
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