Are there specific regulations regarding the installation of pressure gauges on pressure vessels at the site?
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Not long ago, it was noticed that some gas pressure vessels on site did not have pressure gauges attached to them, but there were pressure gauges on the pipes connected to the vessels, and there were no valves in the pipes connecting the pressure gauges to the vessels. I think, since that’s the case, it should be fine. But during one inspection, the inspector suggested that a pressure gauge should be installed on the pressure vessel, so as to allow for direct monitoring of the vessel’s pressure. The logic is definitely sound; it’s just that I’m not sure if there are any specific requirements regarding the installation of pressure gauges – is there a particular way to do it? Since no evidence was found, I had to seek advice from Haiyou. Furthermore, during the research process, the appendix to GB150.1-2011 \"Pressure Vessels\" specifies particular methods for installing safety valves; as shown in the figure, since safety valves can be installed in this way, can pressure gauges be installed in the same manner? Especially for containers with a gaseous medium, in the pipes that are directly connected to the container, there is almost no difference between the internal pressure and the pressure in the pipes – isn’t that possible? I’m struggling as I can’t find any regulatory basis, so I’m turning to everyone for help: handshake
I’m not sure whether it means a pressure gauge mounted directly on the container or one connected via a pipe; I’ve seen both cases, with gauges placed directly on the container as well as those connected through pipes
I am looking for a basis for not installing pressure gauges on pressure vessels – can pressure gauges located on the inlet and outlet pipes that are directly connected to the pressure vessel be used to monitor the pressure parameters of the vessel?
Does this mean that a pressure gauge must be installed on the pressure vessel itself? So, are there any requirements regarding the installation location of pressure gauges on pressure vessels? For example, it must definitely be installed at the top. For pressure vessels with a gas medium, can the pressure gauge be installed in the middle or lower part of the vessel to facilitate inspection and observation?
The accessories or connectors for other uses he mentioned,
I am looking for evidence that it is possible to avoid installing a pressure gauge on the pressure vessel itself, and instead install one on the piping connected to the vessel in order to monitor its pressure parameters. From the installation requirements you mentioned, it is only clear that pressure gauges can be installed directly on the pressure vessel; it is not indicated whether they can also be installed on associated systems or pipelines connected to the vessel. And in item (2), the clause “shall not be connected to any fittings or pipes for other purposes” seems to rule out my idea:
According to safety regulations, pressure gauges are safety accessories for equipment and are generally installed on the equipment. If installed on a pipeline, it is necessary to select an appropriate measurement point; consideration must be given to ensuring that the pressure at the measurement point on the pipeline reflects the pressure inside the equipment. It is also important to ensure that the difference between the pressure at the measurement point and the pressure inside the equipment remains within an acceptable range, and that the risks associated with the equipment are limited and controllable. For example, if there is a pressure reducing valve in front of the equipment at the measurement point, or if the steam entering the equipment causes a significant increase in volume and thus a drop in pressure, then the pressure measured on the pipeline is highly correlated with the pressure inside the equipment, and it is not possible to install the sensor on the pipeline. Whether a pressure gauge is needed on the equipment depends on the relevant product standard requirements, design drawings, and user specifications. HG/T20583-2020 also specifies requirements for pressure gauges in Appendix 3; similar requirements are present in GB/T15063-1995, as shown in Figure 1. Such requirements also apply to pressure-type oxygenators used in power plants, as indicated in Figure 2
The editing above is a bit messy; the requirements for pressure gauges in HG/T20583 are specified in clause 7.4, which refers to Figure 3, not Appendix 3
Thank you so much! You mentioned earlier that under certain conditions pressure gauges can be installed on pipes – is there any source for this?
The product standards do not require that it must be installed on the equipment; designers can determine the locations of pressure measurement points in the pipes so that the measured pressures can represent the pressures inside the container. Users also do not demand that it must be installed on the container itself, and it can be placed at a suitable location in the pipes. However, ordinary designers should avoid taking this risk. For example, in shell-and-tube heat exchangers, the design unit responsible for the liquid side will handle the design of the inlet and outlet pipes.