Threaded flange is also called "TH flange", is a non-welded flange that processes the inner hole of the flange into a thread and cooperates with a threaded pipe to achieve connection. The threaded flange is easy to install and  maintain, usually used in occasions under 4.0Mpa, it is not allowed to be used in some occasions: the temperature is higher than 260℃ and lower than -45 ° C to avoid leakage. This flange is only applicable to the inch size series.