5.3.1 Piping between the barge or offshore unit LNG storage system and the
regasification system shall be equipped with a manually operated stop valve and a
remotely controlled emergency shutdown valve. These valves shall be located as close
to the LNG storage tank as practicable. When the regasification unit is located in
the forward section of the barge or offshore unit, such isolation shall be as near
as possible to the boundary of the forward most LNG storage tank bulkhead and within
the cargo area.
5.3.2 Dry break quick-release connectors shall be provided for use in an
emergency in:
- piping between an LNG supply ship and the barge of offshore
unit;
- send-out gas piping between the barge or offshore unit and
receiving terminal.
5.3.4 The spool piece, reducers, valves and other fittings to which the LNG
storage system or the send-out system is directly connected shall be of approved
material. They shall be of robust construction, adequately supported and suitable
for the stated design conditions and manifold forces. For LNG transfer, attention is
drawn to SIGTTO ‘Manifold Recommendations for Liquefied Gas Carriers’.
5.3.5 Means of draining, purging, inerting and gas-freeing the pipe lines
used for the regasification system shall be provided.
5.3.6 Means of mechanical separation shall be provided between the
regasification piping system and the barge or offshore unit’s inert gas and nitrogen
systems.
5.3.7 All main isolating valves serving the regasification systems and
equipment shall be positioned in a readily accessible location.
5.3.8 The fabrication and installation of the piping associated with the
regasification plant and sub-systems shall be in accordance with the relevant
Sections of these Rules.
5.3.9 Provisions shall be incorporated in the design to minimise the number
of flanged connections. In order to protect personnel from cryogenic burns and
prevent the barge or offshore unit’s structure or other carbon steel structures on
deck from being exposed to brittle fracture due to LNG pressure jet, consideration
shall be given to the fitting of spray shield arrangements to any flanged connection
of piping containing LNG at a pressure above 10 bar g.
5.3.10 Where applicable, all LNG pipework serving the regasification system
shall be suitably thermally insulated and covered with an efficient vapour
barrier.
5.3.11 Both low and high pressure LNG supply pipework serving the
regasification systems is to be subject to a stress analysis, taking into account
ship motions and deflections.