Disconnect pipeline preparation
Assess the need for fencing or barriers (considering the workmanship of other planes);
Provide containment measures in case of material escaping or leakage;
Protecting drainage ditches, stormwater Wells and sewers on the ground;
Estimate the volume of liquid remaining in the container to be disconnected;
Materials held should be labeled for reuse or disposal in accordance with local regulations.
Loosen the bolts that are farthest from the operator on the flange face. Anticipate the risk of material explosion. Replace aging or corroded bolts one by one before disconnecting the piping. Punch, chisel, wrench or other similar tools shall not be used during operation.
Flange splitters or flange clamps or standard wedges can also be used to open flange connections. If a wedge is used, fix it with a chain or wire.
Use barriers where possible, including local barriers to flanges.
Open the pipeline at the lowest level of the equipment so that the residual material can be discharged smoothly.
Bolts on the connection surface should be loosened prior to removal to ensure no internal pressure.
After the system is drained, the valve to be removed opens, closes and opens again to ensure that the accumulated fluid and residual pressure are fully discharged.
If the bonnet needs to be removed, drain the fluid from the system and keep the valve open before loosening the bonnet.
The bolt can only be removed when the liquid is reduced from a steady flow to the droplet.
The nearest safety spray should be marked. If the distance is more than 50 feet, or the reach time is more than 10 seconds, a portable sprinkler or water spray should be available for emergency use.
The factory must clearly mark or physically identify the method in the disconnection program where the disconnection occurs.