A pipe system, comprising: a tubular body having an axis , a bore that is axial and a retainer groove formed in the bore of the tubular body , wherein the retainer groove has a shallow portion with a shallow radius and a deep portion with a deep radius that is greater than the shallow radius; a retainer having a ring shape and_configured to be mounted in the retainer groove , wherein the retainer comprises a radial thickness T 1 that is greater than a radial depth T 2 of the shallow portion of the retainer groove ; and the radial thickness T 1 of the retainer is less than or equal to a radial depth T 3 of the deep portion of the retainer groove , wherein the retainer comprises radial extensions relative to the axis , and the radial extensions are configured to be manipulated to change a dimension of the retainer , wherein the radial extensions are configured to only slidingly engage each other and do not lock together and are configured to extend through an aperture in a wall of the tubular body , wherein the aperture comprises recesses , the radial extensions are configured to have an unrestrained position in the aperture , the radial extensions are configured to have a restrained position in the recesses , and the radial extensions and the retainer are configured to be axially movable between the unrestrained and restrained positions, and wherein, in the unrestrained position, the radial extensions are configured to be circumferentially movable and the retainer is radially movable and, in the restrained position, the radial extensions are configured to be not circumferentially movable and the retainer (31. 131, 231. 331. 431. 531. 731) is not radially movable . a tubular body having an axis , a bore that is axial and a retainer groove formed in the bore of the tubular body , wherein the retainer groove has a shallow portion with a shallow radius and a deep portion with a deep radius that is greater than the shallow radius; a retainer having a ring shape and_configured to be mounted in the retainer groove , wherein the retainer comprises a radial thickness T 1 that is greater than a radial depth T 2 of the shallow portion of the retainer groove ; and the radial thickness T 1 of the retainer is less than or equal to a radial depth T 3 of the deep portion of the retainer groove , wherein the retainer comprises radial extensions relative to the axis , and the radial extensions are configured to be manipulated to change a dimension of the retainer , wherein the radial extensions are configured to only slidingly engage each other and do not lock together and are configured to extend through an aperture in a wall of the tubular body , wherein the aperture comprises recesses , the radial extensions are configured to have an unrestrained position in the aperture , the radial extensions are configured to have a restrained position in the recesses , and the radial extensions and the retainer are configured to be axially movable between the unrestrained and restrained positions, and wherein, in the unrestrained position, the radial extensions are configured to be circumferentially movable and the retainer is radially movable and, in the restrained position, the radial extensions are configured to be not circumferentially movable and the retainer (31. 131, 231. 331. 431. 531. 731) is not radially movable . <EOS>