The minimum test pressure for portable tanks intended for specific substances is specified in the applicable portable tank instruction in 4.2.4.2.6

(c) two thirds of the minimum test pressure specified in the applicable portable tank instruction in 4.2.4.2.6

4.2.4.2.2 For substances of Classes 3 to 9, the portable tank instructions (T1 T34) indicate the applicable minimum test pressure, the minimum shell thickness (in reference steel), bottom opening requirements and pressure relief requirements.

The emergency relief devices shall be dimensioned in such a way that the maximum pressure in the tank never exceeds the test pressure of the tank.

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.

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

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

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.

(a) Portable tanks The tank shall be filled with water or any other non pressurized substance to approximately 97 of the tank volumetric capacity.

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),

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

The tank shall not be pressurized during the test.

Pressure vessel code to which the shell is designed

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.

And it can actually crush an empty soda can.

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

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

4.2.1.13.6 Portable tanks shall be fitted with pressure relief devices and emergency relief devices.

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.

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.

6.6.4.7.1 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.

6.6.2.12.2 The combined delivery capacity of the relief devices in condition of complete fire engulfment of the portable tank shall be sufficient to limit the pressure in the shell to 20 above the start to discharge pressure of the pressure limiting device.

(a) with a degree of filling, for liquids having a viscosity less than 2,680 mm2 s at 20 oC, of more than 20 but less than 80 unless the shells of portable tanks are divided, by partitions or surge plates, into sections of not more than 7,500 litres capacity

6.6.3.7.4 In the case of multi purpose portable tanks, the pressure relief devices shall open at a pressure indicated in 6.6.3.7.1 for the gas having the highest maximum allowable pressure of the gases allowed to be transported in the portable tank.

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

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.

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.

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.

When pressure is lower, the boiling point is lower.

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

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

Keep down!

You have low blood pressure.

6.6.2.7.1 All portable tanks shall be fitted with at least one pressure relief device.

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

Tanks shall be hydraulically tested and internally inspected at intervals not exceeding 2.5 years.

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

6.6.3.7.1 Portable tanks shall be provided with one or more spring loaded pressure relief devices.

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.

(d) the lowest set pressure of the pressure limiting device(s).

Highpressure area here, low pressure here.

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.