66 / 74
Tank Overfill Safety Instrument System
CompEx Rectification - Modification Sheet
P & I Design Ltd
DOCUMENT NO: PX232003_RPT
2 Reed Street, Thornaby, UK, TS17 7AF
ISSUE: A DATE: 08.03.13
Tel: + 44 (0)1642 617444
PAGE 4 OF 5
Fax: + 44 (0)1642 616447
www.pidesign.co.uk3.3
Identified hazards affected
None.
3.4
Impact on functional safety
It is considered that there will be no impact on functional safety from this modification.
Note: If by performing this modification, there is an impact on functional safety, then the
impact must be analysed by returning to the first part of the safety system lifecycle
documentation and review the effect of this change, ensuring that the Safety Integrity Level
and other protection layers are adequate for functional safety.
3.5
Design of the modification
3.5.1 SIS Documentation impacted by the modification
SI297001_DWG
SI297003_DWG
SI297001_SCH
SI297007_RPT
3.6
Implementation plan
LEHHH03 to be replaced and retested when tank 3 back in service.
LEHHH04 to be replaced when tank 4 removed from service, retested when tank 4 back in
service.
JB3 to be added when tank 4 removed from service.
3.7
Testing plan
The Safety Instrument System Panel will require re-testing prior to and following the
modifications.