Regarding pneumatic valves and electromagnetic flowmeters used for hazardous media, are there any differences in process interfaces between WN-RF and PLRF?

For pneumatic valves and electromagnetic flowmeters used with hazardous media, the main standards for process interfaces are WN-RF and PLRF. The difference between these two standards lies in their connection methods and sealing techniques. Among them, WN-RF refers to flange connection, which offers good sealing performance and is suitable for high-pressure and high-temperature applications ； PLRF refers to a flat flange connection; there are no protrusions or recesses on the mating surface, resulting in an average level of sealing performance. Therefore, it is necessary to select the appropriate process interface standard based on the specific application scenario and process requirements. -

What I want to ask is, is there such a distinction between the flange on the pneumatic valve body and the flange on the flow meter body as well?

Yes, there are also differences in connection standards for the flanges on pneumatic valves and electromagnetic flowmeters. For pneumatic valves, their body is usually equipped with flange connections for connecting to piping systems. The common flange connection standards for pneumatic valves are as follows: 1. ANSI flanges (American National Standards Institute): Flange connections of ANSI 150, 300, and 600 grades are suitable for high-pressure applications ； 2. DIN flanges (Deutsches Institut für Normung): Flange connections according to German DIN standards are suitable for the European market ； 3. JIS flanges (Japanese Industrial Standard): Flange connections that comply with Japan’s JIS standards are suitable for the Asian market. For electromagnetic flowmeters, the unit itself is also equipped with flange connections for connecting to pipeline systems. The common flange connection standards for electromagnetic flowmeters are as follows: 1. ANSI flange: suitable for the U.S. market ； 2. GB flanges (national standard flanges): suitable for the Chinese market ； 3. DIN flange: Suitable for the European market ； 4. JIS flanges: Suitable for the Asian market. Therefore, when selecting pneumatic valves and electromagnetic flowmeters, it is necessary to choose the appropriate flange connection standard based on the specific usage conditions and process requirements. -

Is there a difference between PLRF and WN RF on the body?

The main difference between the PLRF and WNRF standards on the body lies in their connection methods and sealing techniques. PLRF is a planar flange connection; its mating surfaces have no protrusions or recesses, resulting in a relatively low sealing performance. It is suitable for applications involving low pressure, low temperature, and non-corrosive media. WNRF features flange connections, offering better sealing performance, and is suitable for applications involving high pressure, high temperature, and corrosive media. Therefore, when selecting pneumatic valves and electromagnetic flowmeters, it is necessary to choose the appropriate connection standards based on the actual operating conditions and properties of the medium. It should be noted that due to the poor sealing performance of PLRF, extra caution is required when using it to ensure its safety and reliability. -

Flat-welded flanges shall not be used on flanges of pipelines carrying hazardous media