What major provides the data in the instrument specifications?
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Hello everyone, I am currently working on the instrument specifications for a project, but I don’t know which major fills in some of the data in the regulating valve data sheet, such as upstream pressure, downstream pressure, min flow, and max flow. Should these two types of data be given by the process major? ? In the valve specifications, should the three types of data, size, calculate cv, and choose cv, be given by the instrument professional? ? In addition, should the above five types of data appear in the process package stage? ? Or is it provided during the basic design stage? ? This post was last edited by Haichuan Zhifeng on 2008-2-20 09:44 ]
I don’t know what to say to the original poster. As a moderator, you should know that it is inappropriate to post duplicate posts.
The process parameters are provided to the instrument by the process professional. The instrument professional calculates and selects the instrument based on the process parameters, and provides the process connection size of the instrument to the process professional.
Upstream pressure, downstream pressure, min flow, max flow are given by the process professional, size is determined according to the process pipeline, calculate cv, choose cv are given by the instrument professional or professional manufacturers are asked to calculate and feedback to the instrument professional. The above five types of data should appear in the process package stage.
Personally, I think it cannot be generalized. The process package design phase is equivalent to the program design phase. Mainly determines the main process. Situation one: The craft package is provided by the designer. Except for special requests. These parameters mentioned by the poster can be provided in the initial design stage. Situation 2: The process package and core equipment are provided by third parties. Third parties refer to those other than the builder (Party A) and the designer. In this case, the builder generally entrusts the designer to check the technology, and the process package is provided by the manufacturer, sometimes including core equipment. Some key operation and equipment parameters will involve property rights issues. Generally, all/part of them are required to be provided to the construction party within a time limit after they are put into operation. ； Much of the design phase is opaque. In this case, some owners will require the main specifications, materials, grades, origins, capabilities, etc. of some equipment (valves, etc.) to be specified in the technical agreement, mainly to delineate costs. ； But it will not be accurate enough to calculate the cv value. After the agreement comes into effect, the process package/core equipment provider will submit the equipment parameters that meet the basic design depth requirements to the design institute, which will approve or produce drawings or other supporting designs. However, in the example in the poster's attachment, I don't understand the huge difference between calculating the cv value and selecting the cv value. Under normal operating conditions, m = C select ÷ C to calculate m as the amplification factor. Generally, the linear control valve takes 1.63; the equal percentage control valve takes 1.97.
Data such as upstream pressure, downstream pressure, min flow, and max flow should be given by the process professional. In the valve specifications, the three types of data, size, calculate cv, and choose cv, must be provided to the valve manufacturer based on the data provided by the above process, and can only be given by the manufacturer after selection and calculation. Of course, if you have a selection tool, you can also choose it yourself.