【Weekly 3 Questions, Question 2】2017.8.12
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This post was last edited by xh8618 on 2017-8-21 08:01. File: bg9.png (Errors were found in the questions; there are 4 errors in total). The original double-flange level gauge installed in the low-temperature condensate tank gave inaccurate readings due to a ruptured diaphragm. One worker modified it into a pressure-transmitting tube differential level gauge, as shown in Figure 2. What are the defects of this modified level gauge? Please list them and explain along with the corrections. After responding, the reference answers can be viewed; points are awarded for correct answers or those that include the key elements. The answer is ① The condenser tank should be located below the upper flange, with liquid entering at the higher level and exiting at the lower level ； ②The piping on the positive and negative sides of the differential pressure transmitter is connected in reverse. ③ The transmitter should be below the lower flange. ④ Pressure guiding tube-type differential pressure level gauges should be equipped with a five-valve assembly. —————————————————————————————————————————————————————————————— The deadline for submitting answers is one week; no scoring will be given after that date. The deadline is 207.08.18. Scoring criteria: Incorrect answers earn 1 point; incomplete answers earn 2–6 points. Correct answers with detailed explanations earn 8 points; answers that are correct but lack sufficient details earn 10–15 points. Please score according to these criteria. Note: If there are editing records after answering, only those who participated will be credited points. For continuous malicious spamming, 2 points will be deducted each time, with no upper limit. Pure numbers, pure emojis, or random letters that have nothing to do with the answer are all considered malicious spamming; points will start to be deducted after three warnings.
①The condensation tank should be below the upper flange; it should have an inlet at a higher level and an outlet at a lower level； ②The piping on the positive and negative sides of the differential pressure transmitter is connected in reverse. ③ The transmitter should be below the lower flange. ④ Pressure guiding tube-type differential pressure level gauges should be equipped with a five-valve assembly
The positive and negative sides of the transmitter are connected in reverse; there is no five-valve assembly; the condenser tank is installed in the wrong location; the transmitter should be installed below the lower flange
①The condensation tank should be below the upper flange; it should have an inlet at a higher level and an outlet at a lower level； ②The piping on the positive and negative sides of the differential pressure transmitter is connected in reverse. ③ The transmitter should be below the lower flange. ④ Pressure guiding tube-type differential pressure level gauges should be equipped with a five-valve assembly.
1. The high-voltage side and low-voltage side of the transmitter are reversed. 2. The condensation storage tank should have a high inlet and a low outlet. 3. The condensation tank should be located above the flange, not opposite to it. 4. The pressure guide tube in the liquid phase should not point upward.
1. The positive and negative terminals of the transmitter are connected in reverse； 2. If the transmitter is installed at too high a position, it should be installed below the liquid-phase flange ； 3. The location of the condensation tank is incorrect; it should be installed at the same level as the gas inlet ； 4. No shut-off valves, drain valves, or vent valves are installed ；
1. In steam systems, pressure and liquid level generally do not require pressure tubes or capillaries.
Why can’t it be used? It can definitely be used, and it can effectively solve the problem of liquid level fluctuations. Ordinary capillary thermometers can reach temperatures over 200°C, while those designed for high temperatures can reach 300°C. Liquid level meters for low-pressure steam condensate have no issues at all, and they also do not require heating for insulation
The gauge reading is above zero; the positive and negative connections are reversed, and there is no primary valve
1. The positive and negative measurement chambers of the transmitter are installed in reverse order. 2. The condensation tank should have inlet at the top and outlet at the bottom. 3. The measurement zero point is offset. 4. A three-valve assembly should be installed
1. No valve is installed between the pressure guide tube and the container； 2. The three-valve assembly is not installed ； 3. No drain valve ； 4. The condensate drain is installed incorrectly; it should lead from a higher position to a lower one, with the outlet located at the bottom of the condensate drain and connecting to the transmitter ； 5. A vent valve should be installed at the upper part of the condensation tank ； 6. The condensed liquid is directed to the negative pressure side, while the positive pressure chamber is connected to the liquid phase.