Double isolation is necessary

Double isolation is necessary

May 11, 2020

Shutdown and isolation of pressurized hot/liquid/gas systems

Double isolation is necessary

For the isolation of chemical/hot/liquid/gas systems where pressure and fluidity exist, the valve should be closed, cut off, locked and emptied (these systems should also cut off the power to the motor or pump in question), but a minimum of double isolation must be used in the following cases.

Double isolation is necessary

Access to restricted Spaces that require access permission

Flammable materials exist or have existed;

Material with PH<2 or PH>12 exists or has existed;

Pressure greater than 100PSI (5,71.5 mmHg) exists or has existed;

Exists or has existed temperature ≥140 F(60 C);

Oxidants, low temperatures or toxic substances exist or have existed;

Harmful bacteria or virus CuanZi exist or have existed (e.g., cooling tower);

Double isolation

Double isolation measures refer to the combination of two types of mechanical isolation, such as "double partition emptying", single valve and blind isolation, single valve and the isolation and release of dismantled/shifted pipelines, which must follow the relevant provisions of the pipeline disconnection procedure.

If only continuous mechanical isolation is allowed on site under the above process conditions, then adequate ppe must be used as a second line of defence.