Direction of high and low pressure sides of differential pressure transmitter
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When installing the transmitter, depending on the measured medium (gas or liquid), the pipe connection direction is either upward or downward, as shown in the figure. Is it required that the high and low voltage sides be higher on the left and lower on the right? Our maintenance staff said it should be higher on the left and lower on the right to make repairs easier. However, in some measurement points the lower connector can be higher on the left and lower on the right, but in others it is an upper connector; when the transmitter is flipped, it becomes lower on the left and higher on the right. I’m asking those with experience – have you heard of this claim? How do I proceed?
Haven’t heard of it; be generous and install the gauge heads vertically, and equip the pressure guiding pipes with hangers
It’s designed for wall mounting, so it’s not easy to modify
This post was last edited by c3h5e8n1 on 2021-1-11 21:15. There is no such thing as high or low voltage sides, nor up, down, left, or right. Currently, there are several reasons for this. One of them is the Rosemount 3051 series – it seems to come only with a horizontal flange, meaning pressure is introduced from below. In the standard configuration of the 3051, the pressure inlet pipe is located at the bottom; the orientation left or right doesn’t matter. Since the hexagonal set screw behind the gauge body can be loosened, the gauge head can be rotated by almost 180°, and rotating it by 90° is no problem at all. What’s the point of having free rotation if it can’t be utilized? Additionally, for the pressure transducers of EJA models, they usually have side flanges, and when selecting them it is possible to choose the direction for the high-pressure and low-pressure sides, so this issue does not arise. For specific details, refer to the EJA selection sample. Finally, the layout is completely absurd; I’ve never seen a pressure transmitter installed inside the pressure inlet pipe up there! -,-
Wait, I took another close look at your question. As a supplementary note, for instruments mounted on a wall with pressure inlet pipes, unless specifically selected during the modeling process, the high and low pressure sides are fixed at the time of manufacture. If you’re not bothered, you could consider changing the range; for differential pressure transmitters, the measurable range is the same for positive and negative pressures. For example, with a range of 0–10 KPa, if you reverse the positive and negative sides, the range becomes -10–0 KPa. There’s no practical difference, but it makes the display less intuitive and can lead to misunderstandings in the readings of the instruments on site, potentially causing problems. This approach is not recommended. Also, what does it mean to be easy to maintain? Why does crossing the two pressure lead pipes make it difficult to maintain? Is it convenient to have the table with the top facing down? It’s absurd.
In the diagram, the tube used for measuring liquids is the inlet pipe, with the exhaust valve located below. Is it not allowed? Additionally, the maintenance staff said that after the transmitter is installed, the left side should be connected to the high-pressure side and the right side to the low-pressure side. However, the high and low pressure sides are determined at the time the transmitter leaves the factory; after the inlet pipe is connected, the left side becomes the low-pressure side and the right side the high-pressure side. As I understand it, this has no impact on the measurement. I just don’t know if it will affect repairs, and it might lead to mistakes later on.
For this process, the interface and the exhaust port can be swapped, right? So even if it’s installed in that position, it can still be adjusted so that the left side is at a higher level and the right side at a lower level
By the way, what product is the manual shown in this screenshot for? It seems pretty strange
Not all models are listed above{:3_53:}
Just have your instrument maintenance staff and instrument installation technicians handle the negotiation.
I don’t understand; what kind of weird request is that?