How to use the five-valve assembly? Take a look and you’ll understand

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The five-valve assembly is typically used in conjunction with differential pressure transmitters. Due to differences among manufacturers, there are two structural designs for this assembly. Below, Changhui Instruments provides a graphical description of its structure as well as the steps for its operation. Five-valve assembly yunrun.com.cn/tech/4418.html Structure of the five-valve assembly: There are two common structures for five-valve assemblies; one of them consists of two drain valves, one balance valve, and two pressure tapping valves ； Another type consists of a drain valve, two balance valves, and two pressure tapping valves. The operation of the five-valve assemblies in these two types of structures differs slightly. Special note: The two drain valves in the five-valve assembly are generally not used for draining waste; they are typically used to release air and liquid from within the diaphragm box of the differential pressure transmitter, and they are employed to zero the differential pressure transmitter after emptying it. Before installing the five-valve assembly and the differential pressure transmitter, drainage is carried out through the drain valve of the five-valve assembly; this allows only the air and liquid in the pressure guiding tube to be removed, but it is not possible to eliminate contaminants from the transmitter diaphragm box. Therefore, when draining a differential pressure transmitter equipped with a five-valve assembly, it is advisable to use the drain screw located at the rear of the transmitter. Installation of the five-valve assembly: 1. The five-valve assembly is installed in conjunction with Rosemount 3051 differential pressure transmitters; 2. It is also installed together with EJA differential pressure transmitters. How to use the five-valve assembly? 1. Operating instructions for the five-valve assembly (two drain valves, one balance valve): ① Under normal operating conditions, the five-valve assembly and the positive and negative pressure guiding valves are open, while the balance valve is closed. ②Use of the five-valve assembly when calibrating the zero point of a differential pressure transmitter: a. First, close the negative pressure valve of the five-valve assembly. b. Open the balance valve on the positive pressure side of the five-valve assembly. c. Open the balance valve on the negative pressure side of the five-valve assembly for calibration. d. After adjusting the zero point of the differential pressure transmitter, close the balance valve on the negative pressure side of the five-valve assembly. e. Close the balance valve on the high pressure side of the five-valve assembly. f. Finally, open the negative pressure valve of the five-valve assembly to put the differential pressure transmitter into operation. 2. Operation instructions for the five-valve assembly (two drain valves, one balance valve): This type of five-valve assembly consists of a three-valve assembly to which two additional drain valves have been added; its operation is identical to that of a three-valve assembly. For more details on how to use this five-valve assembly (with two drain valves and one balance valve), please refer to the article “Steps for shutting down and starting up differential pressure transmitters” on Changhui Instrument Network – no further explanation is needed here.