Pressure relief

opening require ments Pressure

Pressure relief requir ements

6.6.2.8 Pressure relief devices

6.6.3.7 Pressure relief devices

6.6.4.6 Pressure relief devices

Pressure receptacles may not be equipped with any pressure relief device.

6.6.2.9 Setting of pressure relief devices

6.6.2.12 Capacity of pressure relief devices

6.6.2.13 Marking of pressure relief devices

6.6.2.14 Connections to pressure relief devices

6.6.2.15 Siting of pressure relief devices

6.6.3.9 Marking of pressure relief devices

6.6.3.10 Connections to pressure relief devices

6.6.3.11 Siting of pressure relief devices

6.6.4.9 Connections to pressure relief devices

6.6.4.10 Siting of pressure relief devices

Pressure relief requirements are as indicated in 6.6.2.8.3 to prevent crystallization of the product in the pressure relief valve.

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.

6.6.4.7 Capacity and setting of pressure relief devices

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

Emergency pressure relief devices may be used to achieve the full relief capacity prescribed.

There shall be no obstruction in an opening leading to a vent or pressure relief device which might restrict or cut off the flow from the shell to that device.

When a frangible disc is inserted in series with the required pressure relief device, the space between the frangible disc and the pressure relief device shall be provided with a pressure gauge or suitable tell tale indicator for the detection of disc rupture, pin holing, or leakage which could cause a malfunction of the pressure relief system.

When no spring loaded pressure relief device is used, the frangible disc shall be set to rupture at a nominal pressure equal to the test pressure.

The frangible disc shall rupture at a nominal pressure 10 above the start to discharge pressure of the relief device.

The frangible discs shall rupture at a nominal pressure 10 above the start to discharge pressure of the relief device.

Each assembly shall be fitted with one or more pressure relief devices.

The pressure relief devices shall open automatically at a pressure not less than the MAWP and be fully open a pressure equal to 110 of the MAWP.

6.7.5.6.1 Pressure relief devices shall be clearly and permanently marked with the following

The pressure relief devices shall open automatically at a pressure not less than the MAWP and be fully open at a pressure equal to 110 of the MAWP.

The device shall remain closed at all lower pressures. This requirement does not prevent the use of vacuum relief or combination pressure relief and vacuum relief devices.

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

Emergency pressure relief devices may be of the spring loaded, frangible or fusible type.

6.6.2.13.1 Every pressure relief device shall be plainly and permanently marked with the following

6.6.3.9.1 Every pressure relief device shall be plainly and permanently marked with the following

6.6.4.8.1 Every pressure relief device shall be plainly and permanently marked with the following

1 See for example CGA Publications S 1.2 2003 Pressure Relief Device Standards Part 2 Cargo and Portable Tanks for Compressed Gases and S 1.1 2003 Pressure Relief Device Standards Part 1 Cylinders for Compressed Gases .

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

Frangible discs not in series with a spring loaded pressure relief device are not permitted.

6.6.4.6.4 Pressure relief devices shall be approved by the competent authority or its authorized body.

When a specific portable tank instruction is specified in Column 10 for a specific dangerous goods entry additional portable tanks which possess higher test pressures, greater wall thicknesses, more stringent bottom opening and pressure relief device arrangements may be used.

T absolute temperature in Kelvin ( C 273) above the pressure relief devices in the accumulating condition

The pressure relief devices shall be of the type that will resist dynamic forces including surge.

4.1.3.6.4 Unless otherwise indicated, pressure receptacles may be provided with an emergency pressure relief device designed to avoid bursting in case of overfill or fire accidents.