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Nustar Terminals – Belfast Terminal
IHLA Safety Instrument System - Functional Safety Assessment
P & I Design Ltd
DOCUMENT NO: NU271001_RPT
2 Reed Street, Thornaby, UK, TS17 7AF
ISSUE: F DATE: 30.06.17
Tel: + 44 (0)1642 617444
PAGE 12 OF 72
Fax: + 44 (0)1642 616447
www.pidesign.co.ukDocument Number NuStar_SIL_Report_Belfast_20110128 Version 2.3 Dated 8
th
February
2011 Title Safety Integrity Level (SIL) Verification Report Section 4 Demand Mode.
It is stated that the proof test interval will be annually.
However, BS EN 61508 – 4: 2010 Section 3.5.16 redefines low demand as detailed below:
No reference in NuStar documentation.
At FSA meeting:
Operators do the testing, Liquiphants are tested (1 tank per week) more often than annually.
Testing is recorded.
Monthly tests on valves will be continued with recording of times to open and close.
Annual testing on the radar transmitters by a controlled fill to activation point using a tank to
tank transfer. It was pointed out at the FSA that this method of test resulted in taking the
process into a dangerous state. Terminal Management explained that this is conducted using
tank to tank transfers at lower rates and is fully monitored during the operation.
At the FSA it was indicated that the surge calculations show that a valve closure time of less
than 7 seconds could lead to dangerous surge conditions. The actual valve closure times are
approx. 90 seconds.
Response time to be included in the SRS. (Action 3 completed, SRS document
NU271003_RPT, Section 4.5)