Definition of instrument tube and valve components for pressure transmitters.
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I have a question regarding instrument tubing and valves: many of the projects I’m working on require that these components be from foreign brands. How is this criterion determined? For example, my pressure transmitters are equipped with one-valve and two-valve assemblies; logically speaking, the root valve falls under the category of equipment-related components, so can it still be considered an instrument piping fitting? I don’t see any clear explanation from the design institute either. The pressure gauge is equipped with only a check valve – is this check valve considered a gauge tube fitting? Are there any standards that clearly define this?
One-valve or two-valve assemblies are primarily used in operation to control and regulate the connection between the pressure transmitter and the system, and they are generally considered to fall under the category of instrument piping valves. Although these valve components are located near the equipment side, their function is to ensure the proper operation of the measurement system; therefore, they are considered instrument piping valves. As for whether foreign brands are required, it is usually determined by the specific technical requirements of the project. If it is not clearly specified in the design institute’s guidelines or project standards, it is recommended to verify directly with the project manager or the design institute. .
It is generally specified in the design documents, namely the instrument installation diagram. If it is a gauge marked on the instrument, or it should be specified as belonging to the process piping specialty. If it relates to the project, check whether a first valve is listed in the instrument material table. If you require a second valve assembly, this can be indicated either in the instrument data table or in the installation drawings; generally, the second valve assembly is considered part of the materials covered by the instrumentation team. Under normal circumstances, the primary valve on the pipeline is under the responsibility of the process pipeline, while the primary valve on the equipment is under the responsibility of the instrumentation.
Please refer to Part 2 HG/T20636.2-2017 of the standard \"Specifications for the Design Management of Automatic Control Systems in Chemical Plants\" HG/T20636-2017, or Appendix A of the standard \"Specifications for the Quality Inspection of Petrochemical Instrumentation Project Construction\" SH/T 3551-2013.
We are suppliers of complete sets of equipment, specifically those related to chemical pumps. The client requires that the instrumentation pipes and valves be from Swagelok. What gives us trouble is deciding whether to use Swagelok products for the pressure gauges and pressure transmitters, or ordinary domestic globe valve manufacturers – the cost difference in this regard is not negligible at all. Regarding the classification, it can be seen that the first type of valves falls under the design and procurement scope of the piping specialty, while the latter ones fall under the instrumentation specialty. But what exactly does \"supply as a complete set\" mean?
Whether to use imported brand pipe fittings is generally determined by the owner, and it’s not absolute