Safe Handling of Tank Containers - ITCO

ICHCA International Safety Panel Briefing Pamphlet No 30
4.4.3 In addition the space may be filled with an insulating material. Some tanks
may consist of a metal vacuum jacket, an outer shell containing a small
quantity of liquefied nitrogen and an inner shell intended to contain the
actual liquefied gas to be transported.
4.4.4 These highly specialised tank containers represent less than 1% of the
worldwide total. They do not have any refrigeration equipment (for example
as reefer tank containers do).
5 Service Equipment, Fittings and Fixtures
5.1 The definition of service equipment is made in Annex 1 however in this section
the use of fittings will be used as a substitute and will encompass service
equipment as defined by the IMDG Code and the closing devices for openings
on tank shells which the IMDG Code considers to be part of the shell rather
than as service equipment. Fittings are therefore defined as items attached to
the tank shell that perform a role that relates to the loading or discharge of the
cargo, or the safety of the pressure vessel.
5.2 A separate term fixtures will be used to define all those items that are attached
to the frame or which perform a role that protects the pressure vessel.
5.3 Fittings (top of shell)
5.3.1 Access / Loading Hatch referred to as a Manway.
5.3.1.1 One or more manways are cut into the top of the shell and each consists of
a neck ring, a lid and a gasket seal. The neck ring will be fabricated from a
compatible material to the shell and is a shaped pad that is welded to the
pressure vessel.
5.3.1.2 Manways are provided to allow access by suitably qualified technicians and
repairers into the shell for periodic inspection. They are also often used on
standard tank containers as an opening for filling.
5.3.1.3 ISO 1496 / 3 states that the “size of the manway shall be a minimum of 500
mm in diameter and shall be determined by the need for men and machines
to enter the tank to inspect, maintain or repair the inside. However the
nature of the cargo and the designation of the tank will set the specific
manway lid configuration.
5.3.1.4 Domed manway lids – these are hinged and sealed against the neck rings
by a number of “swing bolts” – see picture 16.
Picture 16 Picture 17 Picture 18
5.3.1.5 Flat bolted flanged manway lids – circular, flat plates are used to cover the
manways by attaching them to the neck ring using a number of bolts. Picture
17 and Picture 18 show two examples of bolted manway lids each with a
secondary use. Picture 17 shows a configuration of valves mounted on the
lid and Picture 18 shows an example of a bolted manway lid with a smaller
diameter loading hatch. This allows a top loading facility and increased
internal pressure.
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