Determination of the design pressure of the pipelines before and after the steam pipeline pressure reducing valve
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I would like to ask everyone: There is a project in which the steam pressure at the boiler outlet is 1.0 MPa, while the pressure required for the process is 0.3–0.4 MPa. I plan to carry out pressure reduction in the boiler room; the design pressure before reduction is set at 1.2 MPa. But can I keep the design pressure the same as before reduction, or can it be lowered? What factors need to be considered in this?
It can reduce design pressure, with a separation at the flange
Is the pipe diameter large? If not, then the outer diameter and wall thickness of the pipe are the same. It’s not advisable to reduce the pipe grade, as this could lead to valve failures or issues related to water hammer. In any case, when the diameter isn’t large, there isn’t much difference between the wall thickness and the outer diameter
The pipe diameter is not large; the main pipeline is DN150
To reduce pressure, a safety relief device should be installed to prevent bud stagnation
From the boiler room to the process units, it’s a bit far, isn’t it?
Do not reduce pressure inside the boiler room; instead, do it near the point where steam is used. The advantages are: 1) Increased overall heat capacity of the steam system； 2) The diameter of the delivery pipeline can be reduced, lowering investment costs and saving energy ； 3) Stabilize using vapor pressure ； . . . . . For more, you can follow the WeChat official account “Fured Steam Energy Saving”.
The wall thickness is the same for DN150 pipes; there are pipe grades of 10 kg and 16 kg, with an outer diameter of 159 and a wall thickness of 4.5
The wall thickness is the same for DN150 pipes; there are pipe grades of 10 kg and 16 kg, with an outer diameter of 159 and a wall thickness of 4.5
According to the principles for determining design pressure outlined in GB50316, the design pressure for a pipeline and its American-made components should not be less than the pressure under the most severe conditions resulting from the combination of internal or external pressures and temperature during operation. If a pressure reducing valve fails, the pressure behind it will certainly reach 1.0 MPa; therefore, it is reasonable to adopt a design pressure of 1.2 MPa for the entire system.