A check valve stop assembly and method of retaining the check valve stop assembly in a check valve flow body without external fixation means, wherein the check valve stop assembly includes a threaded check valve stop insert and a check valve stop housing including a threaded interior sidewall that defines a void space therein. The body portion has a first side and a second side opposite to the first side in the axial direction. Based on the created table, a GUI screen is displayed for receiving selection of one of the ordinal ranks. The interference reflector substantially transmits light having the second optical characteristic and substantially reflects light having the first optical characteristic.