with respect to each other application_number US 84641304 A description referring to fig1 the wellhead 10 has a bore 12 that remains constant in the region shown one or more stop pins 14 are in respective bores 16 and sealed with seals 18 the hanger or other device to be suspended 20 has a retaining ring 22 attached at thread 24 an energizing ring 26 rests on ring 22 and pins 14 when the hanger 20 is lowered in wellhead 10 to the position shown in fig1 wellhead 10 also has a recess 28 in which a ring 30 is fitted and secured in recess 28 with a split ring retainer 32 ring 30 has a groove 34 defined by surfaces 36 38 and 40 those skilled in the art will appreciate that groove 34 can be integral to the wellhead 10 as an option using the ring 30 to create the groove 34 whose peak coincides with bore 12 allows the ring 30 to be replaced if the groove 34 becomes worn or damaged over time the hanger 20 features an energizing taper 42 and an adjacent limit shoulder 44 which can be flat as shown in fig1 or sloping downwardly in a direction toward centerline 46 as shown in fig9 in some situations a slight angle may be desirable to reduce or more uniformly distribute stresses in the load support area an inherent benefit of this design is to prevent accumulation of debris as shown in fig1 the expanding load shoulder 48 has a top surface 50 that will ultimately engage shoulder 44 surfaces 52 54 and 56 correspond to surfaces 36 38 and 40 of groove 34 such that when load.