ISO 17775:2006

ISO 17775:2006 specifies the detail dimensions of the male connector interfaces, fitted to an aircraft, used for servicing of the potable water systems, the toilet-flush water systems, and the toilet drain systems currently in common use. ISO 17775:2006 is applicable to all commercial aircraft with water and toilet systems and is recommended for military and private aircraft that use water and toilet systems.
ISO 17775:2006 does not include requirements for the ground half (female) couplings or protective caps, but provides sufficient interface details for such items to be designed. It does not include any specified dimensions for the clearance required around the connector on the aircraft body itself for either any protective caps or ground half couplings, although general recommendations are made.