The work pressure is relatively low; how should the design pressure and hydrostatic test pressures be determined?
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For a vertical heat exchanger with a diameter of 600 mm and a height of 6000 mm, the operating pressure is 0.06. Therefore, I determine its design pressure to be 0.06 × 1.1 + the hydrostatic pressure due to the liquid, which is 0.06; this gives 0.13. For hydraulic testing (in horizontal format), a pressure of 151 is required, plus another 0.06 for the hydrostatic pressure due to the liquid. Isn’t this double-counting the hydrostatic pressure?
The last edit to this post was made by SDHZZXM on 2016-11-11 at 09:00. Is it necessary to take into account the hydrostatic pressure when considering design pressures?
The hydrostatic pressure due to the liquid filling is now the same as the operating pressure. When calculating the design pressure for the lower cylinder and the head, don’t you need to include this hydrostatic pressure?
I have now understood that the design pressure does not require the hydrostatic pressure of a liquid column; the pressure used for determining the thickness of a component at the corresponding design temperature includes the hydrostatic pressure of a liquid column. When the hydrostatic pressure exerted on the component is less than 5% of the design pressure, it can be ignored. Confused the calculated pressure with the design pressure
The design pressure can be appropriately increased. Heat exchangers have minimum wall thickness requirements, and appropriately increasing the design pressure does not increase costs.
The operating pressure is 0.06+0.06=0.12; the design pressure is 0.12*1.1=0.13, and the test pressure is 0.13*1.25
Is that so? Does the test pressure not need to take temperature into account?
Generally, it is like this; there are also other special cases, which are more complicated and difficult to explain
Since it is a heat exchanger, it should at least have design parameters for two media, hot and cold. If the working pressure is 0.06 MPa, it is also possible to use the strength design standards specified in NB/T 47003.1-2009 \"Steel Welded Atmospheric Pressure Vessels\", and there are no restrictions regarding design or manufacturing qualifications. :)
It’s not that it can’t be explained; it’s you who haven’t understood it
Temperature is not directly related to pressure; for substances such as steam, the higher the temperature, the greater the pressure. Operating pressure refers to the highest pressure that can be reached at the top of the equipment. Go read a book by yourself