Regarding the selection of flanges

PN5.0 DN100 flanges can be used, as well as PN10.0 DN100 flanges

The flange specifications are of course PN5.0 and DN100; it is also necessary to specify the flange type, standard, material, seal surface type, etc.

The matching flange should be selected based on the valve’s flange type, material, structure, and seal surface type. This issue can generally be resolved by purchasing a valve along with matching flanges and gaskets.

It is necessary to specify whether the flange belongs to series A or series B. The material of the flange, its pressure rating, and the type of sealing surface also need to be indicated; otherwise, it will affect the outer diameter tolerances of the components connected to it, as well as the welding and sealing processes

Valves with PN5.0, DN100 can use ANSI 300lb flanges

Both the flanges of the valve and those of the associated pipes are standard; they can be selected based on nominal pressure and nominal size. Chinese products follow Chinese standards, while American products follow American standards.

The original poster is being too general! If you are designing a piping system, it is recommended that you ask the valve supplier to provide you with a diagram showing the external dimensions of the valve. This diagram will usually specify in detail the manufacturing standards for the valve as well as the standards for its connection flanges; if the connection flanges are not standard ones, detailed drawings will also be provided! You can simply choose a flange with the corresponding pressure rating and pipe diameter as specified in the drawings! This is the most direct and effective method! If you just want to learn it on your own! Then at the very least, you need to figure out what type of valve it is – is it a butterfly valve, a globe valve, or a check valve? And what is the connection type of this valve: wafer type or flanged connection? Finally, consider the sealing surface and the material issue! The following suggestions are for your reference! (1) If it’s a stop valve, it must be flanged! You can only use flanges of the same pressure rating; ones with a higher or lower pressure rating may not be compatible! As for choosing which type of flange with sealing surface to use, it depends on the type of sealing surface on the flange of the valve body itself; it should match that type! (2) If it’s not a stop valve, but rather a butterfly valve or a check valve, then you need to determine its connection method! These types of valves are available in wafer-type and flange-connected versions! If it is a valve of the PN5.0MPa pressure class as mentioned by LZ, it should also be flanged! The method is the same as before~~~ If it’s a clamp-type type, then just choose the flange that is used for connecting to your piping system! (3) Among them, I saw that a few people earlier mentioned issues related to national standards, American standards, as well as Series A and Series B! My understanding is as follows: First, since LZ mentioned DN and PN, it must be the European standard system, rather than the American standard system ； The American standard system is represented by NPS and CLASS, that is, what is commonly referred to as inch and pound ratings! Secondly, regarding the issue of Series A and Series B, according to **the standards, they should be called Series I and Series II; the choice depends on the system’s piping! If the system pipes are made of Series I tubing, then Series I flanges should be used ； If the system pipes use Series II tubing, choose Series II flanges! (4) As for the material of the Flange, the most important thing is to ensure it is consistent with the system piping ； The material of the valve is generally taken into account when selecting it, with regard to consistency of material! So there’s no need to worry about electrochemical corrosion caused by inconsistent materials! This post was last edited by yunmusong on 2009-2-26 13:06.]