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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 11 OF 72
Fax: + 44 (0)1642 616447
www.pidesign.co.ukGas Oil Transfer Shutdown Valve
Kerosene Transfer Shutdown Valve
(Future Kerosene line Valve) – not included in system at present
It will be necessary to provide, within the SRS, a block diagram showing functionality of the
various SIF’s. (Action 4 completed, SRS document NU271003_RPT, Section 2.3)
There is no reference to common cause failure. Again confirmation is required if all valves
are required to operate to stop product flow i.e. 7oo7 or if only one supply line will be used at
any one time. If 1oo1 then common cause failure may not be applicable.
Response in FSA meeting:
Activation of any high level causes all valves to close. In normal operation, up to two lines
with ESV’s can be feeding a single tank at any one time. This is never done with gasoline
import.
The terminal utilises Nitrogen for the actuator. The valves are all ball valves of Pekos
manufacture. All actuators are Actreg and the solenoid valves are Norgren.
Common cause failure may be an issue with 2oo2 system operation. To be covered in the SRS
and in the PFD verification calculations. (Action 3 completed, SRS document
NU271003_RPT, Section 2.2) (Action 9)
The Functional Specification details the fails safe state of the SIF. The SRS should also
include more details of the safe state of the process and actions on shutting down against a
ship import. (Action 3 completed, SRS document NU271003_RPT, Section 4.5)
No reference. (Action 3 completed, SRS document NU271003_RPT. There are no safe
process states which, when occurring concurrently create a separate hazard)
Document 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 demand on the system is less than once a year and as such is classified as
low demand mode.