scope:

1. INTRODUCTION

Calculations were performed using both hand calculations and finite element methods to determine the design adequacy of the clamp type connect or hubs contained in the API Spec 16A (1*).

The hand calculations were carried out by means of a computer program prepared for the Association of Well Head Equipment Manufacturers (2-11) and used to validate the designs of the clamp type connectors previously contained in API Spec 6A (12).

The finite element calculations were done with the ANSYS general purpose finite element program, using the Stif 42 two dimensional (axisymmetric) element.

Both operating and gasket seating conditions were evaluated with the hand calculations. The stresses due to gasket seating were found to be negligible relative to those for operating conditions, so gasket seating was not addressed in the finite element calculations.

Gasket seating and retaining loads were calculated using the methods adopted by the AWHEM Clamp End Connector Task Group (3),(4),(11). The earlier calculations were done for the RX gasket only, so they had to be expanded to include the BX gaskets called out in Spec 16A.

Allowable values for the calculated stresses were determined by means of Paragraph III. D.2.1 of Spec 16A (1).