first sealing surface is rigidly fixed with respect to the first connection member the flow sealing member has external threads that mate with the threaded through hole a second flow passage aligned with the first flow passage of the first member and a second sealing surface that seals with the first sealing surface around the first and second flow passages upon application of sealing force via rotation of the external threads in the threaded hole application_number US 26091699 A description referring to fig2 fluid coupling assembly 110 includes a check valve module 112 a connecting plate 114 and two flow sealing assemblies 116 a 116 b check valve module 112 has a circular first sealing surface 118 defining an inlet 120 and an outlet 122 inlet 120 is large enough to prevent e g a drop in pressure experienced by fluid entering inlet 120 sufficient to cause degassing or cavitation the interior 124 of module 112 defines an inflow path 126 in the direction of arrow b and an outflow path 128 in the direction of arrow a interior 124 also includes two check valves 130 a 130 b disposed within flow paths 126 and 128 check valve 130 a prevents flow in the direction of arrow a and check valve 130 b prevents flow in the direction of arrow b module 112 is disposed within a cylindrical conduit 132 the structure and operation of module 112 is described more fully in u s patent application ser no 09 260 914 entitled u201c check valve module u201d filed the same date as this application and incorporated herein by reference in.