A few things I don’t understand about the safety valve
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I'm currently working on a safety valve textbook, but there are a few terms in it that I don't quite understand. Is the throat diameter of a safety valve the diameter of the flow channel? ? Secondly, what is the connection between the nominal diameter and the flow channel diameter? Also, I saw that the nominal grade written on some safety valve nameplates is 150/150lb. What does this mean? ? Please give me some advice, friends.
Throat diameter is the diameter of the flow channel. The nominal diameter is larger than the throat diameter. lb is the abbreviation of pound.
The throat diameter of the safety valve refers to the cross-sectional area at the smallest diameter at the nozzle. I'm not sure about the latter part, 1lb=4.45N. Please look for information on safety valve process calculations, such as process manuals.
The inner sealing surface of the safety valve. When the system pressure reaches the safety valve tripping pressure, the safety valve will trip. After the tripping, the two sealing surfaces will separate. The inner diameter of the lower sealing surface (discharge medium channel) should be the throat diameter. Personal understanding, for reference only.
What is said on the second floor is that the throat diameter of the safety valve is slightly larger than the nominal diameter of the flow channel. The nominal grade written on the nameplate of the safety valve is 150/150lb. This is not clear.
150LB/150LB means that both import and export are 150LB
This post was last edited by flute6 on 2009-11-27 10:10 Throat Area The cross-sectional area at the smallest diameter of the safety valve nozzle. When piping, the inlet pipe should be greater than or equal to the throat diameter, but not smaller than the throat diameter. If necessary, add a reducer. The throat diameter of the safety valve is the diameter of the flow path, which is smaller than the nominal diameter. The nominal grade is 150/150lb, which means: Nominal diameter DN150/pound class 150 pounds (2.0MPa). :) :)
Valve nominal diameter: It refers to the nominal diameter of the pipe at the connection between the valve and the pipe and all other accessories, in millimeters (expressed in DN). Contents that the safety valve metal nameplate should contain 1) Model, specification (diameter) 2) Pressure level 3) Flow channel diameter 4) Nominal pressure 5) Operating temperature, medium 6) Rated displacement coefficient 7) Manufacturer, manufacturing approval number 8) Year and month of manufacture 9) Product number 10) Inspection mark
1. The throat diameter is the diameter of the flow channel. The flow channel area is the cross-sectional area at the smallest diameter in the safety valve nozzle. Orifice diameter is an internal dimension of a safety valve. The nominal diameter is the diameter of the inlet flange of the safety valve. When piping, the inlet pipe must be greater than or equal to the throat diameter. 2. The nominal grade is 150/150lb.: The nominal diameter of the safety valve inlet flange is DN150/pound class 150 pounds (2.0MPa).
I very much agree with the views on the 7th and 9th floors above, they are very complete and comprehensive.
The flow channel diameter is the diameter corresponding to the flow channel area. The flow channel area is the minimum cross-sectional area of the flow channel between the inlet end of the valve disc and the sealing surface of the closing member. It is used to calculate the theoretical displacement without any resistance. Throat diameter, the diameter of the throat of the valve seat.