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Local Fuel plc - Shoreham Oil Terminal
Safety Instrument System Functional Safety Assessment Stage 5
P & I Design Ltd
DOCUMENT NO: LF364100_RPT
2 Reed Street, Thornaby, UK, TS17 7AF
ISSUE: A DATE: 15.06.2015
Tel: + 44 (0)1642 617444
PAGE 16 OF 32
Fax: + 44 (0)1642 616447
www.pidesign.co.uk5.2.10
Is there a description of the relationship between inputs, logic solver and outputs and any
specific requirements requiring 1oo2, 2oo2 systems or specific requirements regarding
nuisance tripping. BS EN Clause 10.
Section 2.4 of the SRS provides a simplified system model of the SIF, this together with
Section defines the inputs, logic solver and outputs of the SIS.
5.2.11
Has the mean time to repair been specified with consideration to availability of spares and
labour. BS EN 61511 Clause 10.
Section 3 of the SRS defines a MTTR of 24 hours, it further states that the filling of the tanks
are on a batch process with extremely long intervals between imports providing for proof
testing and other maintenance to be carried out in these time intervals. Section 4.5 of this FSA
defines further the proposed intention of a spare valve.
5.2.12
Have manual shutdowns been considered. BS EN 61511 Clause 10.
Section 4.6 of the SRS states that manual shutdown is available by manual control of the valve
and also on operation of the ESD pushbutton.
5.2.13
Is there a requirement for overrides and if so has the effect on the SIF been considered. BS
EN Clause 10.
Section 2.3 of the SRS states that there are no facilities for overriding the SIF.
5.2.14
Have the interfaces with the Basic Process Control System (BPCS) been defined. BS EN Claus
10.
Section 4.4 of the SRS defines BPCS interface.
5.2.15
Can the BPCS interfere with the safe operation of the SIF. BS EN 61511 Clause 10.
Section 4.4 that the BPCS can have no effect on the operation of the SIS.
5.2.16
Has the method of resetting the system been defined. BS EN Clause 10.
Section 3 of the SRS states that automatic reset of the final element shall not be possible.
5.2.17
Have environmental and abnormal events been considered. (e.g. temperature, humidity, fire
etc.) BS EN Clause 10.
Section 3 of the SRS provides information on the environmental operating parameters of the
SIS.
5.2.18
If the SIS logic solver is software based have the application software requirements been
specified. BS EN Clause 10 & 12.
The logic solver is not software based.