Protection of fittings mounted on the upper part of the tank

The fittings and accessories mounted on the
upper part of the tank shall be protected against
damage caused by overturning. This protection
may take the form of strengthening rings,
protective canopies or transverse or longitudinal
members so shaped that effective protection is
given.
                                                                       

 

Items of equipment

Suitable non-metallic materials may be used to manufacture service and structural equipment.
The items of equipment shall be so arranged as to be protected against the risk of being wrenched
off or damaged during carriage or handling. They shall exhibit a suitable degree of safety
comparable to that of the shells themselves, and shall in particular:
- be compatible with the substances carried; and
- meet the requirements of 6.8.2.1.1.
Piping shall be designed, constructed and installed so as to avoid the risk of damage due to thermal
expansion and contraction, mechanical shock and vibration.
 
As many operating parts as possible shall be
served by the smallest possible number of
openings in the shell. The leakproofness of the
service equipment including the closure (cover)
of the inspection openings shall be ensured even
in the event of overturning of the tank, taking
into account the forces generated by an impact
(such as acceleration and dynamic pressure).
Limited release of the tank contents due to a
pressure peak during the impact is however
allowed.
The leakproofness of the service equipment shall
be ensured even in the event of the overturning of
the tank-container.
The gaskets shall be made of a material compatible with the substance carried and shall be replaced
as soon as their effectiveness is impaired, for example as a result of ageing.
Gaskets ensuring the leakproofness of fittings requiring manipulation during normal use of tanks
shall be so designed and arranged that manipulation of the fittings incorporating them does not
damage them.

Each bottom-filling or bottom-discharge opening in tanks which are referred to, in Column (12) of
Table A of Chapter 3.2, with a tank code including the letter "A" in its third part (see 4.3.4.1.1) shall
be equipped with at least two mutually independent closures, mounted in series, comprising
- an external stop-valve with piping made of a malleable metal material and
- a closing device at the end of each pipe which may be a screw-threaded plug, a blank flange
or an equivalent device. This closing device shall be sufficiently tight so that the substance is
contained without loss. Measures shall be taken to enable the safe release of pressure in the
discharge pipe before the closing device is completely removed.
Each bottom-filling or bottom-discharge opening in tanks which are referred to, in Column (12) of
Table A of Chapter 3.2, with a tank code including the letter "B" in its third part (see 4.3.3.1.1 or
4.3.4.1.1) shall be equipped with at least three mutually independent closures, mounted in series,
comprising
- an internal stop-valve, i.e. a stop-valve mounted inside the shell or in a welded flange or
companion flange;
- an external stop-valve or an equivalent device 6
 
one at the end of each pipe as near as possible to the shell
and
- a closing device at the end of each pipe which may be a screw-threaded plug, a blank flange or
an equivalent device. This closing device shall be sufficiently tight so that the substance is
contained without loss. Measures shall be taken to enable the safe release of pressure in the
discharge pipe before the closing device is completely removed.
However, in the case of tanks intended for the carriage of certain crystallizable or highly viscous
substances and shells fitted with an ebonite or thermoplastic coating, the internal stop-valve may be
replaced by an external stop-valve provided with additional protection.
The internal stop-valve shall be operable either from above or from below. Its setting - open or closed
- shall so far as possible in each case be capable of being verified from the ground. Internal stopvalve
control devices shall be so designed as to prevent any unintended opening through impact or an
inadvertent act.
The internal shut-off device shall continue to be effective in the event of damage to the external
control device.
In order to avoid any loss of contents in the event of damage to the external fittings (pipes, lateral
shut-off devices), the internal stop-valve and its seating shall be protected against the danger of being
wrenched off by external stresses or shall be so designed as to resist them. The filling and discharge
devices (including flanges or threaded plugs) and protective caps (if any) shall be capable of being
secured against any unintended opening.
The position and/or direction of closure of shut-off devices shall be clearly apparent.
All openings of tanks which are referred to in Column (12) of Table A of Chapter 3.2, by a tank code
including letter "C" or "D" in its third part (see 4.3.3.1.1 and 4.3.4.1.1) shall be situated above the
surface level of the liquid. These tanks shall have no pipes or pipe connections below the surface
level of the liquid. The cleaning openings (fist-holes) are, however, permitted in the lower part of the
shell for tanks referred to by a tank code including letter "C" in its third part. This opening shall be
capable of being sealed by a flange so closed as to be leakproof and whose design shall be approved
by the competent authority or by a body designated by that authority.
 
6 In the case of tank-containers of less than 1 m3 capacity, the external stop-valve or other equivalent device may
be replaced by a blank flange.

Tanks that are not hermetically closed may be fitted with vacuum valves to avoid an unacceptable
negative internal pressure; these vacuum-relief valves shall be set to relieve at a vacuum setting not
greater than the vacuum pressure for which the tank has been designed (see 6.8.2.1.7). Hermetically
closed tanks shall not be fitted with vacuum valves. However, tanks of the tank code SGAH, S4AH or
L4BH, fitted with vacuum valves which open at a negative pressure of not less than 21 kPa (0.21 bar)
shall be considered as being hermetically closed. For tanks intended for the carriage of solid
substances (powdery or granular) of packing groups II or III only, which do not liquefy during
transport, the negative pressure may be reduced to not less than 5 kPa (0.05 bar).
Vacuum valves and breather devices (see 6.8.2.2.6) used on tanks intended for the carriage of
substances meeting the flash-point criteria of Class 3, shall prevent the immediate passage of flame
into the shell by means of a suitable protective device, or the shell of the tank shall be explosion
pressure shock resistant, which means being capable of withstanding without leakage, but allowing
deformation, an explosion resulting from the passage of the flame.
If the protective device consists of a suitable flame trap or flame arrester, it shall be positioned as
close as possible to the shell or the shell compartment. For multi-compartment tanks, each
compartment shall be protected separately.

The shell or each of its compartments shall be provided with an opening large enough to permit
inspection.

(Reserved)

Tanks intended for the carriage of liquids having a vapour pressure of not more than 110 kPa (1.1 bar)
(absolute) at 50 oC shall have a breather device and a safety device to prevent the contents from
spilling out if the tank overturns; otherwise they shall conform to 6.8.2.2.7 or 6.8.2.2.8.

Tanks intended for the carriage of liquids having a vapour pressure of more than 110 kPa (1.1 bar) at
50 °C and a boiling point of more than 35 °C shall have a safety valve set at not less than 150 kPa
(1.5 bar) (gauge pressure) and which shall be fully open at a pressure not exceeding the test pressure;
otherwise they shall conform to 6.8.2.2.8.

Tanks intended for the carriage of liquids having a boiling point of not more than 35 °C shall have a
safety valve set at not less than 300 kPa (3 bar) gauge pressure and which shall be fully open at a
pressure not exceeding the test pressure; otherwise they shall be hermetically closed7.

Movable parts such as covers, closures, etc., which are liable to come into frictional or percussive
contact with aluminium shells intended for the carriage of flammable liquids having a flash-point of
not more than 60 ºC or for the carriage of flammable gases shall not be made of unprotected
corrodible steel.

If tanks required to be hermetically closed are equipped with safety valves, these shall be preceded
by a bursting disc and the following conditions shall be observed:
The arrangement of the bursting disc and safety valve shall be such as to satisfy the competent
authority. A pressure gauge or another suitable indicator shall be provided in the space between the
bursting disc and the safety valve, to enable detection of any rupture, perforation or leakage of the disc
which may disrupt the action of the safety valve.
 
7 For the definition of "hermetically closed tank" see 1.2.1.

Type approval

The competent authority or a body designated by that authority shall issue in respect of each new
type of tank-vehicle, demountable tank, tank-container, tank swap body, battery-vehicle or MEGC a
certificate attesting that the type, including fastenings, which it has inspected is suitable for the
purpose for which it is intended and meets the construction requirements of 6.8.2.1, the equipment
requirements of 6.8.2.2 and the special conditions for the classes of substances carried.
The certificate shall show:
- the results of the test;
- an approval number for the type;
 
                                                                    
The approval number shall consist of the
distinguishing sign used on vehicles in international
road traffic 8 of the State in whose territory the
approval was granted and a registration number.
- the tank code in accordance with 4.3.3.1.1 or 4.3.4.1.1;
- the alphanumerical codes of special provisions of construction (TC), equipment (TE) and type
approval (TA) of 6.8.4 which are shown in column (13) of Table A of Chapter 3.2 for those
substances for the carriage of which the tank has been approved;
- if required, the substances and/or group of substances for the carriage of which the tank has
been approved. These shall be shown with their chemical name or the corresponding
collective entry (see 2.1.1.2), together with their classification (class, classification code and
packing group). With the exception of substances of Class 2 and those listed in 4.3.4.1.3, the
listing of approved substances may be dispensed with. In such cases, groups of substances
permitted on the basis of the tank code shown in the rationalised approach in 4.3.4.1.2 shall be
accepted for carriage taking into account any relevant special provision.
The substances referred to in the certificate or the groups of substances approved according to the
rationalised approach shall, in general, be compatible with the characteristics of the tank. A
reservation shall be included in the certificate if it was not possible to investigate this compatibility
exhaustively when the type approval was issued.
A copy of the certificate shall be attached to the tank record of each tank, battery-vehicle or MEGC
constructed (see 4.3.2.1.7).
The competent authority or a body designated by that authority shall at the request of the applicant
carry out a separate type approval of valves and other service equipment for which a standard is
listed in the table in 6.8.2.6.1, in accordance with that standard. This separate type approval shall be
taken into account when issuing the certificate for the tank, if the test results are presented and the
valves and other service equipment are fit for the intended use.

If the tanks, battery-vehicles or MECGs are manufactured in series without modification this approval
shall be valid for the tanks, battery-vehicles or MECGs manufactured in series or according to the
prototype.
A type approval may however serve for the approval of tanks with limited variations of the design that
either reduce the loads and stresses on the tanks (e.g. reduced pressure, reduced mass, reduced
volume) or increase the safety of the structure (e.g. increased shell thickness, more surge-plates,
decreased diameter of openings). The limited variations shall be clearly described in the type approval
certificate.
 
8 Distinguishing sign of the State of registration used on motor vehicles and trailers in international road traffic,
e.g. in accordance with the Geneva Convention on Road Traffic of 1949 or the Vienna Convention on Road Traffic of
1968.
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