1 Application scope
1.0.1 This specification is applicable to the chemical process system specialty. For the valves mentioned, safety valves, steam traps, sampling valves and pressure reducing valves are not included, while the pipe fittings (such as restriction orifices and blind flanges) with similar functions as valves are included, and the shut-off valves are taken as the general name of these valves. The shut-off valves are used to cut off the fluid or change the flow direction of the fluid. Such valves shall be set according to the requirements of production (including normal production, startup and shutdown as well as special working conditions), maintenance and safety, and by considering the economic rationality.
1.0.2 Setting of valves and selection of appropriate types (not model). The setting of valves is a piece of important work for personnel of process system specialty in case of preparing PI diagrams. For the contents described in this specification, the general requirements for production and safety have been taken into account. In case of carrying out engineering design with reference to this specification, the personnel of system specialty shall make trade-offs according to the specific conditions of the project, local meteorological conditions, inter-plant cooperation, operation requirements for devices, fluid characteristics and special requirements of users, as well as economy.
1.0.3 This specification comprehensively and generally introduces the setting of valves in the listed situations. For the detailed requirements for various chemical units, see the basic unit mode of PI diagram of corresponding units.
1.0.4 This specification also introduces the characteristics of general industrial valves and the factors to be considered in case of selecting valves in engineering design.
2 Setting of valves
2.0.1 Setting of valves at the boundary
2.0.1.1 Shut-off valves shall be set at the boundary of the equipment (usually inside the battery limit of the equipment) for process materials and utility materials pipelines, with the following exceptions:
(1) Exhaust system.
(2) The discharge pipe when the emergency discharge tank is set outside the boundary; in these two cases, if a valve must be set, it shall be subjected to car sealed open (C.S.O).
(3) Material pipes that will not cause material swap and accidents.
(4) Material pipes not required to meter.
1 Application scope
2 Setting of valves
3 Selection of valve types in engineering design
