Small branch connections are frequently installed on piping systems for the attachment of vent, drain, test and instrumentation connections. The ASME and ANSI piping design codes provide stress intensification factors i (SIF) to guide the piping designer on the design of such components.Appendixes A, B and C are copies of the ASME and ANSI subsections pertinent to this area. In summary, the ASME Code requires i to be no less than 1.5 and the calculated i must be doubled (minimum of 2.1) for a component without sufficient branch to run radius r? (per ASME NC 3673.2(b)-2).Since there is no such control of r? in the tests described in this report an index of no less than 2.1 would be required.The ANSI SIF’s for this type of connection are equal to 0.9h2/3 which is approximately 1.7 for the component tested in this report. For ANSI B31.1 an SIF of 1.0 could possibly be applied for the run-side loads of a branch connection since the SIF indicates only “for checking branch ends.” The goal of this program was to obtain run moment bending fatigue test data on such connections. The tests are displacement controlled 4-point bending tests on 4” schedule 40 carbon steel pipe, type A106-B with three types of branch connections.This configuration was selected due to the extensive amount of test data on similar pipes by Markl and to meet the requirements of reference 7 in this report.