Basic parameters of valve:

1. Nominal diameter: the nominal diameter refers to the nominal diameter of the channel at the connection between the valve and the pipeline, that is, the rounded diameter for reference, expressed by DN. It represents the size of the valve.

2. Nominal pressure: the nominal pressure refers to the design given pressure related to the mechanical strength of the valve, expressed in PN. For nominal pressure series, see GB / t1048-2005 "definition and selection of piping components PN (Engineering pressure)".

The concept of Engineering pressure has been included in the relevant standards of UK and USA, but the class is still adopted. There is no strict correspondence between the nominal pressure and the scale temperature because of the difference between them. In the actual application process, the corresponding relationship between the two references is shown in the following table:

valve

3. Applicable media: according to the requirements of valve material and structure, the applicable media of valve are as follows:

① Gas medium, such as air, steam, nitrogen and natural gas; genius valve

② Liquid medium, such as oil, water, etc;

③ Containing solid medium;

④ Corrosive medium and highly toxic medium.

4. Test pressure:

① Strength test pressure: the specified pressure for the strength test of valve pressure parts according to the specified test medium.

② Sealing test pressure: the specified pressure for valve sealing test according to the specified test medium.