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Local Fuel – The Shoreham Oil Terminal
Gasoline Import - Safety Instrument System
P & I Design Ltd
DOCUMENT NO: LF364006_RPT
2 Reed Street, Thornaby, UK, TS17 7AF
ISSUE: C DATE: 13.05.16
Tel: + 44 (0)1642 617444
PAGE 14 OF 23
Fax: + 44 (0)1642 616447
www.pidesign.co.uk6.3
Final Element Subsystem
For the gasoline tanks, the final element sub-system comprises of a single electro hydraulic
operated spring return actuator mounted onto a 90° ball valve. Failure mode is that the valve
will close on loss of electrical signal. The valve is certified ATEX II 2GD EExde IIB T6. The
ball valve provides a tight shut-off.
The tanks contain gasoline at atmospheric conditions. The materials of construction of the valve
is carbon steel with 316L stainless steel ball, on which the stored product has no chemical
effect.
The system is a 1oo1 configuration and currently the valve is not utilised as part of the BPCS.
For the remaining distillate and additive tanks the final element is purely an alarm annunciated
in the control room.
6.3.1 Import Valve XV162
The valve is fitted with open and closed limit switches and the rotork actuator will check that
the valve has completely closed following each operation prior to system reset.
The valve utilised is a typical ¼ turn ball valve. The valve is to be utilised in a SIS and specified
with an oversize actuator to ensure effective closing.
The actuator is fitted with a restrictor for slow closing, this is important, as if the valve slammed
shut, the consequences to the import line and ship could be considerable. It must be ensured
that the slow closing restrictor is protected against un-authorised adjustment, resulting in the
valve being unable to vent and therefore not closing.
The speed of closing the valve is to be set such that following operation of the high level SIF,
the product entering the tank, during the closing time, cannot overspill.
Import flow rate 400 m
3
/hr