Can double-flange reverse installation be used properly?
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Today, I was working on a project involving the maintenance of a new chemical instrumentation unit. The person in charge of calibration said that there are many double flanges in this device that are installed in the wrong orientation, and this was done intentionally to meet certain manufacturing requirements. Inspection is scheduled for tomorrow; I’m not sure if it will be acceptable. If the positive and negative pressure chambers of these double flanges are installed incorrectly, what effects will that have on their measurement range and drift?
Personally, I think it shouldn’t work properly; I’ve never heard of any manufacturing process requiring such a thing.
This post was last edited by Yann on 2017-5-6 at 16:53. Theoretically, for double flange types, it is still possible to measure the differential pressure even if they are installed in the wrong direction. But there’s a slight logical issue. Because: △P = P_positive – P_negative. When installed in reverse, P_pos = P_gas + P_silicone oil. If P_gas = 0 (since the gas pressure will cancel out in the end), then P_pos = P_silicone oil = ρ_silicone oil × g × H; that is, P_pos = ρ_silicone oil × g × H. Meanwhile, P_neg = ρ_liquid × g × h. So the question arises: how should the range of this gauge be set? The range would be from ρ_silicone oil × g × H to (ρ_liquid × g × h – ρ_silicone oil × g × H). As you know, ρ_silicone oil × g × H is a positive value, while (ρ_liquid × g × h – ρ_silicone oil × g × H) is close to 0. Therefore, the range should be set between 10 KPa and 0 KPa. Is it possible to set it this way? Even if it’s set up successfully, isn’t it a bit inconvenient for future maintenance? When the header shows 7.5 Kpa, isn’t it a bit strange to think that the liquid level is 25%? It is recommended to follow the specifications and the instructions.
It cannot be installed in reverse; some settings cannot be completed.
Modern smart transmitters can be installed in either orientation; simply change the settings
Follow the specifications, follow the instructions.
It can be measured; simply set the transmitter to reverse measurement
Where is it set to measure in reverse direction? Could you send the setup steps?
It depends on the specific brand of the transmitter; different manufacturers use different ones； It must be an intelligent transmitter; not all transmitters can be configured in this way.
Why would a properly functioning gauge need to be installed in the reverse direction and have its settings altered? If it’s due to manufacturing requirements, it’s better to purchase the gauge using the standard manufacturing parameters