![Show Menu](styles/mobile-menu.png)
![Page Background](./../common/page-substrates/page0030.jpg)
Immingham East Terminal – Gasoline Overfill Protection
Safety Instrument System
P & I Design Ltd
DOCUMENT NO: SI277001_RPT
2 Reed Street, Thornaby, UK, TS17 7AF
ISSUE:
F
DATE: 31.10.14
Tel: + 44 (0)1642 617444
PAGE 10 OF 29
Fax: + 44 (0)1642 616447
www.pidesign.co.uk6.3
Operation
The Safety Instrument Functions (SIF) are to prevent overfill of the storage tanks.
6.3.1 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 valve on the
tank high high alarm activation.
For the No.4 East tanks, on detection of a tank high high level, fault or power supply failure,
the output will be removed to the actuator on that tank’s import valve, resulting in the ball
valve closing. The valve cannot be re-opened until the 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 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 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.