
ASME B31.3 Limitations on Threaded Joints
Most threaded joints in ASME B31.3 piping systems are made with taper threads in accordance with ASME B 1.20.1. Figure 5.1 shows a taper thread. These threaded joints are generally acceptable for Normal Fluid Service and Category D Fluid Service. Paragraph 314.1(a) states that threaded joints should be avoided in any service where crevice corrosion, severe erosion, or cyclic load may occur. Cyclic loading is not defined and this limitation is rather unclear, because all syste