Test pressure means the maximum gauge pressure at the top of the shell during the pressure test

6.6.2.8.5 When the shell is fitted for pressure discharge, the inlet line shall be provided with a suitable pressure relief device set to operate at a pressure not higher than the MAWP of the shell, and a stop valve shall be fitted as close to the shell as reasonably practicable.

6.6.3.5.5 In addition to filling, discharge and gas pressure equalizing orifices, shells may have openings in which gauges, thermometers and manometers can be fitted.

6.6.4.7.1 In the case of the loss of vacuum in a vacuum insulated tank or of loss of 20 of the insulation of a tank insulated with solid materials, the combined capacity of all pressure relief devices installed shall be sufficient so that the pressure (including accumulation) inside the shell does not exceed 120 of the MAWP.

6.6.3.8.1 The combined delivery capacity of the relief devices shall be sufficient that, in the event of total fire engulfment, the pressure (including accumulation) inside the shell does not exceed 120 of the MAWP.

6.6.3.2.8 Shells shall be designed to withstand an external pressure of at least 0.4 bar gauge above the internal pressure without permanent deformation.

Frangible discs shall rupture at nominal pressure equal to the test pressure of the shell.

While under pressure, the portable tank shall be inspected for any leaks in the shell, piping or equipment.

6.6.2.2.10 A shell which is to be equipped with a vacuum relief device shall be designed to withstand, without permanent deformation, an external pressure of not less than 0.21 bar above the internal pressure.

A shell that is not to be fitted with a vacuum relief device shall be designed to withstand, without permanent deformation an external pressure of not less than 0.4 bar above the internal pressure.

Pressure vessel code to which the shell is designed

When for reasons of portable tank arrangements the plate cannot be permanently attached to the shell, the shell shall be marked with at least the information required by the pressure vessel code.

When for reasons of portable tank arrangements, the plate cannot be permanently attached to the shell, the shell shall be marked with at least the information required by the pressure vessel code.

Test pressure means the maximum gauge pressure at the top of the shell during the hydraulic pressure test equal to not less than 1.5 times the design pressure.

(b) the maximum effective gauge pressure to which the shell is designed, which shall be

This pressure should be lower than the test pressure of the tank involved.

Leakproofness test means a test using gas subjecting the shell and its service equipment to an effective internal pressure of not less than 25 of the MAWP

Leakproofness test means a test using gas subjecting the shell and its service equipment, to an effective internal pressure not less than 90 of the MAWP

The vacuum relief device shall be set to relieve at a vacuum setting not greater than minus ( ) 0.21 bar unless the shell is designed for a higher external over pressure, in which case the vacuum relief pressure of the device to be fitted shall be not greater than the tank design vacuum pressure.

4.1.3.6 Pressure receptacles for liquids and solids

6.6.2.9.2 The required pressure relief device shall be set to start to discharge at a nominal pressure of five sixths of the test pressure for shells having a test pressure of not more than 4.5 bar and 110 of two thirds of the test pressure for shells having a test pressure of more than 4.5 bar.

6.6.2.3.2 Shells shall be designed and constructed to withstand a hydraulic test pressure not less than 1.5 times the design pressure.

6.6.4.6.1 Every shell shall be provided with not less than two independent spring loaded pressure relief devices.

6.6.4.14.3 The initial inspection and test of a portable tank shall include a check of the design characteristics, an internal and external examination of the portable tank shell and its fittings with due regard to the refrigerated liquefied gases to be transported, and a pressure test referring to the test pressures according to 6.6.4.3.2.

When the shell and its fittings have been pressure tested separately, they shall be subjected together after assembly to a leakproofness test.

When the shell and equipment have been pressure tested separately, they shall be subjected together after assembly to a leakproofness test.

TP24 The portable tank may be fitted with a device located under maximum filling conditions in the vapour space of the shell to prevent the build up of excess pressure due to the slow decomposition of the substance transported.

(i) the maximum effective gauge pressure to which the shell is designed as defined in (b) of the MAWP definition (see above) and

6.6.2.15.1 Each pressure relief device inlet shall be situated on top of the shell in a position as near the longitudinal and transverse centre of the shell as reasonably practicable.

6.6.3.11.1 Each pressure relief device inlet shall be situated on top of the shell in a position as near the longitudinal and transverse centre of the shell as reasonably practicable.

6.6.4.10.1 All pressure relief device inlets shall be situated on top of the shell in a position as near the longitudinal and transverse centre of the shell as reasonably practicable.

Maximum allowable working pressure (MAWP) means the maximum effective gauge pressure permissible at the top of the shell of a loaded portable tank in its operating position including the highest effective pressure during filling and discharge

(a) the maximum effective gauge pressure allowed in the shell during filling or discharge or

This box can be used to change the pressure of the gas.

for tanks not more than test pressure of the tank (according to 4.2.1.13.4 tank shall be designed for a test pressure of at least 0.4 MPa),

6.6.3.3.2 Shells shall be designed and constructed to withstand a test pressure not less than 1.3 times the design pressure.

For shells with vacuum insulation the test pressure shall not be less than 1.3 times the sum of the MAWP and 100 kPa (1 bar).

6.6.4.14.11 In all cases when cutting, burning or welding operations on the shell of a portable tank have been effected, that work shall be to the approval of the competent authority or its authorized body taking into account the pressure vessel code used for the construction of the shell.

TP16 The tank shall be fitted with a special device to prevent under pressure and excess pressure during normal transport conditions.

Pressures on criminal justice systems

The shell design shall take into account the minimum MAWP values provided in portable tank instruction T50 in 4.2.4.2.6 for each non refrigerated liquefied gas intended for transport.

When the shell is to be subjected to a significant vacuum before filling or during discharge it shall be designed to withstand an external pressure of at least 0.9 bar gauge above the internal pressure and shall be proven at that pressure.

6.6.4.7.3 Under the circumstances described in 6.6.4.7.1 and 6.6.4.7.2 together with complete fire engulfment the combined capacity of all pressure relief devices installed shall be sufficient to limit the pressure in the shell to the test pressure.

(b) the maximum effective gauge pressure to which the shell is designed which shall be not less than the sum of

(b) a closed system test when the rise in pressure in the shell is measured over a period of time.