法兰（Flange），又叫法兰凸缘盘或突缘。法兰是管子与管子之间相互连接的零件，用于管端之间的连接；也有用在设备进出口上的法兰，用于两个设备 之间的连接，如减速机法兰。法兰连接或法兰接头，是指由法兰、垫片及螺栓三者相互连接作为一组组合密封结构的可拆连接。管道法兰系指管道装置中配管用的法 兰，用在设备上系指设备的进出口法兰。法兰上有孔眼，螺栓使两法兰紧连。法兰间用衬垫密封。法兰分螺纹连接（丝扣连接）法兰、焊接法兰和卡夹法兰。法兰都 是成对使用的,低压管道可以使用丝接法兰，四公斤以上压力的使用焊接法兰。两片法兰盘之间加上密封垫，然后用螺栓紧固。不同压力的法兰厚度不同，它们使用 的螺栓也不同。水泵和阀门，在和管道连接时，这些器材设备的局部，也制成相对应的法兰形状，也称为法兰连接。凡是在两个平面周边使用螺栓连接同时封闭的连 接零件，一般都称为"法兰"，如通风管道的连接，这一类零件可以称为"法兰类零件"。但是这种连接只是一个设备的局部，如法兰和水泵的连接，就不好把水泵 叫"法兰类零件"。比较小型的如阀门等，可以叫"法兰类零件"。
　　铸铁管(CastIronPipe)，用铸铁浇铸成型的管子。铸铁管用于给水、排水和煤气输送管线，它包括铸铁直管和管件。劳动强度小。按铸造方法不 同，分为连续铸铁管和离心铸铁管，其中离心铸铁管又分为砂型和金属型两种。按材质不同分为灰口铸铁管和球墨铸铁管。按接口形式不同分为柔性接口、法兰接 口、自锚式接口、刚性接口等。其中，柔性铸铁管用橡胶圈密封；法兰接口铸铁管用法兰固定，内垫橡胶法兰垫片密封；刚性接口一般铸铁管承口较大，直管插入 后，用水泥密封，此工艺现已基本淘汰。

　　Flange (Flange), also known as flange flange plate or flange. The flange is a part which is connected between the pipe and the pipe, which is used for the connection between the pipe end. Flange connection or flange connection is defined by the flange, gasket and bolt are connected as a group of combined seal structure of the detachable connection. Pipe flange refers to the pipeline installation of piping flange, used in equipment refers to equipment import and export flange. There are two bolt holes on the flange, the flange connect. Flange gasket seal. Sub threaded flange connection (threaded connection), flange welding flange and flange clamp. All flanges are used in pairs, and the low pressure pipe can be used for the use of wire connecting flanges, and the use of four kg or more pressure on the use of welding flanges. Between the two pieces of the flange and the sealing pad, and then use the bolt fastening. Different pressure flange thickness, the use of bolts are also different. Pumps and valves, in connection with the pipe, the part of the equipment, and also made of the corresponding flange shape, also known as flange connection. All in the use of bolt connection in the two plane around the closure of the connecting parts, are generally referred to as the "flange", such as ventilation pipe connection, this kind of parts can be called "flange type parts". But this connection is only a part of the device, such as the connection of the flange and the pump, the pump is called "flange type parts". Relatively small, such as valves, can be called "flange type parts".

　　Cast iron pipe (CastIronPipe), cast iron pipe. Cast iron pipe for water supply, drainage and gas transmission line, it includes cast iron pipe and pipe fittings. Labor intensity is small. By casting method is different, is divided into continuous cast iron pipe and the centrifugal cast iron pipe, including centrifugal cast iron pipe is divided into two kinds of sand mold and metal mold. For pipe and cast iron pipe ductile cast iron by different materials. According to the different forms of interface is divided into flexible joint, flange interface, self anchored interface, rigid interface etc.. Among them, the flexible cast iron pipe rubber ring seal; flange interface cast iron pipe flange fixed, rubber flange gasket seal; rigid interface of the general cast iron pipe, straight pipe, with cement seal, this process has been basically eliminated.