Stub Ends for Flanged Joints

What is a stub end and why should it be used? Stub ends are buttweld fittings that can be used (in combination with a lap joint flange) alternatively to welding neck flanges to make flanged connections. The use of stub ends has two advantages: it can reduce the total cost of flanged joints for piping systems in high material grades (as the lap joint flange does not need to be of the same material of the pipe and the stub end but can be a lower grade);它加快了安装过程，因为可以旋转圈接头法兰以促进螺栓孔的对齐。存根末端的短图（ASA和MSS存根末端）可用，尺寸高达80英寸。

存根终端应用程序

A stud end and alap joint flange可以一起用作建立法兰连接的替代方法than welding neck flanges.

The two devices to be combined, in this case, are:

• The stub end，本质上是一根管道，一端向外张开，另一端准备焊接到相同的孔尺寸（NPS =标称管道尺寸）的管道上，materialand wall thickness. The most widely used fabrication tool for stub ends is the flaring machine, which is able to flare the end of the pipe and then cuts it to length.

• 圈接头法兰，which is used to actually bolt the two lengths of pipe together.

圈接头存根的好处

存根的使用具有这两个优势：

Reduces the overall cost of the flanged joint

通常，膝关节法兰的级别低于存根端和管道的材料，thussaving the total weight of high-grade material used for the flanged joint.

例子：

对于SS316管道，而不是使用完整的316焊接颈部法兰，而是组合SS316存根端和碳钢圈接头法兰可以做同样的工作，但是SS316材料的总重量也会较低，而且成本也是如此。

Essentially, stub ends allow to minimize the weight of high-grade material in stainless, duplex, and nickel alloy piping, saving costs. Of course, the bigger the diameter and the class of the flanges, the higher the saving!

促进法兰的安装

The lap joint flange can be rotated on the pipe and simplify the alignment of the bolt holes of the mating flanges