pressure transmitter on each pressure vessel

dear,
i have booster pumps that are running on pressure based on the pressure transmitter that comes with the booster pumps kit and there are pressure transmitters on each pressure vessel(please refer to below picture). Pumps and all the instruments are being monitored by a SCADA system.

my question is: are the pressure transmitters on each pressure vessel are necessary? from common practice i mean.

From my understanding is that if diaghragm is broken, pressure in the system will remain the same as measured with the pressure transmitter that comes with the booster pumps kit, what will change is the running frequency of the booster pumps, so that the operator in the SCADA will know that something wrong has happened.

in what sense are these pressure transmitters on the pressure vessels are necessary and if they are really important to be kept.

thanks for your feedback.

It appears that each pressure vessel features an isolation valve. While the pressure transmitters on the vessels may well be redundant, they are the only means of monitoring the pressure of an isolated vessel. Is that important for your process?

Yes, it could be that your customer only needs 1 or 2 of the pressure tanks at times, with the other one closed off with the valve. Or it could be that each tank is isolated before it is emptied, it which case the pressure will drop to 0 as its contents are forced out by the pressure.

I don't think you could find any "common practice" for this type of process. What you need to do the job depends on the details, which you did not give. Maybe you do not know the process details, but before removing anything, you do need those details. Even then if the customer wants, specified, and is paying for 3 pressure transmitters on those vessels, then that is what you should do.

Maybe it is a simple case of desired redundancy for a dangerous point that must be controlled even when 1 PT fails. If the valves are all open, then you have 4 pressure transmitters that should read approximately the same pressure (except for friction losses in the pipelines). If one PT fails, then you still have 3 backup readings to use for control.

I have seen this before, for different reasons.

1-Booster pump is feeding hazardous substance and leaks have to be detected. (leaks would create inconsistencies in the readings)

2-Charge pressure drop or diaphragm failure detection: Yes, it's true, the system pressure will be that of the booster pump. However, because of the charge pressure ratio, a pressure vessel MAY loose pressure at a slower rate than the others because it will become "dead" BEFORE the others. The others will then be feeding it with pressure. (this is a tricky one to explain but you actually notice this with data acquisition). The charging slope will also be slightly different. You definitly CAN detect failures with this assembly. In your post, you were thinking about system pressure when pump is running. You forgot about charge and discharge slopes. They can reveal a lot about the health of your system

Just keep in mind that even if you may think the pressure transmitters are not required, a bladder type pressure vessel should still have a pressure indicating device for safety purposes. Since a device is needed the designers may have chosen to go with pressure transmitters all around - this is just a guess without more process specific information.

On safety, I was recently given the not so pleasant assignment to investigate an industrial accident where a maintenance tech had isolated a pressure vessel and disconnected it from the system. Mistakenly believing it to be unpressurized he loosened the connection. The high pressure jet he released penetrated the palm of his hand, cutting through the muscle, and exiting the back of his hand in three places. High pressure fluid followed the spaces between the muscles and traveled through his wrist and into his arm. Multiple extensive and massively invasive surgeries were required to open his hand and arm up to remove the fluid, irrigate the tissue, and repair the damage, followed by extensive physical therapy. So even if you do remove the transmitters, I have to strongly recommend that some kind of pressure indicating device be retained.