A403 WP316L Long Stub End Type A, Wrought Stainless Steel Fitting Connection To Lap Joint Flanges

An A403 WP316L lap joint stub end is a butt-weld pipe fitting manufactured in accordance with ASTM A403, made of WP316L austenitic stainless steel. Typically referring to a stub end, it is commonly used in conjunction with a lap joint flange to facilitate detachable connections in piping systems. This product is primarily manufactured to meet ASME B16.9 or MSS SP-43 standards and is available in long and short patterns depending on the length.

The forming process can involve cold or hot working. Due to the presence of molybdenum in its material composition, the WP316L lap joint stub end offers excellent corrosion resistance, particularly against chloride pitting, making it suitable for corrosive media environments such as those found in the chemical, petroleum, and pharmaceutical industries. Additionally, its low carbon content ensures good weldability, contributing to a long service life.

Stub End Product Form and Function
 

• Structure: It is a short piece of pipe, with one end designed for butt welding to the pipe and the other end flared outward to form a flat, ring-shaped face (the lap).
• Working Principle: This lapped face does not weld to another flange. Instead, it acts as the bearing surface for a lap joint flange. During installation, the lap joint flange is slipped over the straight portion of the stub end. When bolts are tightened, the faces of the two stub ends (or one stub end and another flange) are pressed together via a gasket to create a seal.
• Advantages: This design allows the flange to rotate freely, making bolt hole alignment much easier. It is particularly suitable for piping systems that require frequent dismantling for cleaning or where precise alignment is critical (such as in pharmaceutical and food industries).

Mechanical Properties of ASTM A403 WP316L Stub End