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Immingham Storage Co Ltd – Immingham East Terminal
IME-SIS1 - Safety Instrument System Safety Requirement Specification
P & I Design Ltd
DOCUMENT NO: SI277010_RPT
2 Reed Street, Thornaby, UK, TS17 7AF
ISSUE: G DATE: 31.10.14
Tel: + 44 (0)1642 617444
PAGE 4 OF 13
Fax: + 44 (0)1642 616447
www.pidesign.co.uk4 East Tanks
The SIS logic solver will be configured for all in scope gasoline tanks, future tanks will be
located in the ROSOV logic panel. Cabling infrastructure will be installed for all tanks to
allow the installation of a tank side valve and relocation to the SIS logic solver should the
tank be required for gasoline duty. The SIS logic solver to be allocated with space and
infrastructure for 7 additional gasoline storage tanks. Each tank on SIS duty will have an
individual tank-side import / export valve that will close on the activation of the independent
high high level switch on that tank or on activation of an individual tank isolation pushbutton
located at the exit of the bund.
All valves will also close on activation of the 4 East Crash Stop.
2.2
Operation
The Safety Instrument Functions are to prevent overfill of the storage tanks.
The No. 4 East tanks will have actuated import/export valves which again will automatically
close on the activation of the independent high high level switch for that particular tank. The
following valves are included in the design:
XV56101 - Tank 561 Import/Export Valve
XV56401 - Tank 564 Import/Export Valve
XV56801 - Tank 568 Import/Export Valve
2.2.1 No. 4 East Tanks
There are six possible import routes. Although there are six pipelines, a batch import process
to any particular tank will only use a single pipeline. As there is no process control system
which confirms the route, this design will operate by closing the tank-side import/export
valve on the tank independent high high alarm activation.
For the No.4 East tanks, on detection of a tank independent high high level, fault or power
supply failure, the output will be removed to the actuator on that tank’s import/export valve,
resulting in the ball valve closing. The valve cannot be re-opened until the independent high
high level, fault or power supply failure are returned to a healthy state. Then on operation of a
momentary reset pushbutton (one on the SIS logic solver panel plus facility for remote
operation) the actuated ball valve will open (if selected to open at local pneumatic control
station).
There is no requirement to override this SIF in the event of an activation of the independent
high high level switch as there is a dedicated export route using hoses under management
procedures which will allow for product to be removed from the tank. Management
controlled use of this is described elsewhere.
The valves will be operated, cycled, periodically on a monthly basis. This will provide a form
of regular stroke testing. Taking this into consideration, and the fact that only one valve will
be open to allow import to any one tank, the SIS shall be designed as a 1oo1 system
throughout, providing all clauses of BS EN 61511 are satisfied.