This European Standard specifies the installation and removal requirements for adaptors and reducers@ threaded@ with lockring for pipe couplings 24??ccording to EN 4833 and EN 4836. This standard establishes an accurate procedure of adaptor installation@ removal and reinstallation to ensure the repeatability of the installation operation and to ensure the effective compliance to sealing and locking requirements. The adaptor shown on all Figures of this standard is given as an example for the 24??nternal cone interface according to EN 6123. This procedure is used for adaptors 24??for nominal pressure up to 35 000 kPa (5 080 psi).