Safety valve on the pump outlet
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A safety valve has been installed at the outlet of the feeding pump in the tank area. The medium includes methanol, toluene, etc., and the pump is a centrifugal pump. What is this safety valve used for?
Diaphragm pump, gear pump, or centrifugal pump? For pipeline expansion?
Centrifugal pumps generally do not require safety valves, while positive displacement pumps need them; the outlet of the safety valve leads back to the pump’s inlet line.
Should we consider thermal expansion or water hammer?
Installing a safety valve on the pump outlet is not ideal, as it tends to trigger prematurely.
This post was last edited by CHANGBAISHI on 2020-11-23 09:20. There are two factors determining whether to add it or not: one is the subcooling of the medium, and the other is the requirements of the process. To determine whether it is necessary to install additional safety valves, it is recommended to examine the process diagram, which shows the pressure and temperature of the pump, and to use the physical and chemical properties of the medium to decide whether such an addition is appropriate. “The approach of \"touching the elephant blindly\" is not advisable; it is provided for reference only.
This post was last edited by Clouds of flowing water shine on 2020-11-23 09:21. It was asked that this is to prevent expansion. The pump has a head of 40m at its outlet. What should be the setting for the safety valve’s discharge pressure, and how is it calculated?
Prevent the pressure from rising excessively due to the temperature increase of the medium inside the pipeline after the valves at both ends of the pipeline are closed. Basis: Article 5.5.6 of the \"Code for Fire Protection Design of Petrochemical Enterprises (2018 Edition)\” (GB 50160-2008): For pipelines carrying liquefied hydrocarbons, Class A B, and Class A liquids, in which the valves at both ends are closed and external factors may cause an increase in the pressure of the fluid, pressure relief safety measures must be implemented.