Requirements for mechanical isolation
Selection of isolation method for process flow
A) single-valve isolation, that is, the isolation requirements of equipment are realized by closing a single valve at the inlet and outlet of equipment, facilities and devices. Suitable for isolation of systems with low isolation level requirements, such as isolation of steam systems with inlet and outlet pipe sizes and unlimited medium pressure; Pipe diameter size is not restricted and upstream pressure is not high seawater, fire water, cooling water and other media pipeline isolation; And the isolation of non-toxic gas medium system with lower pipeline pressure (less than 1MPa) and unrestricted pipe diameter size.
B) double-valve isolation and unloading method, that is, a method of isolation by using the double isolation valve that closes the inlet and outlet of equipment, facilities and devices, and releasing the medium between the two valves at the same time. Suitable for the isolation of flammable liquid medium system with lower pipeline pressure (less than 0.2mpa) and smaller pipe diameter size (less than 25.4mm); Isolation of non-toxic gas medium system with high pipeline pressure (more than 1MPa) and unrestricted pipe diameter size; And other types of media in particular pipe diameter size and pressure system isolation.
C) single-valve isolation plus blind plate, that is, a single isolation valve is used to close the inlet and outlet of equipment, facilities and devices, and the medium in the pipeline is emptied to facilitate the insertion of blind plate so as to achieve the ultimate purpose of equipment isolation. Suitable for isolation of medium systems such as seawater with high pipeline pressure (> 1.7mpa) and unrestricted pipe size; Isolation of flammable liquids, gases and toxic gas media systems without pipe pressure or size restrictions.