Water port closure assembly

A fill port assembly comprising:

• a housing having an opening therethrough;
• a fill port located in and extending through the opening defining a flow passage through the fill port from a first end to a second end, the flow passage having an axis defined between the first end and the second end;
• and
• a closure mechanism moveable between an open position in which the flow passage is open and allows fluid flow therethrough and a closed position in which the flow passage is closed and prevents fluid flow therethrough, wherein the closure mechanism comprises:
• a cap attached at a first side of the cap to a first side of the housing via a hinge, the cap pivotable about the hinge between an open position with respect to the fill port and a closed position to close the second end of the fill port, and a catch assembly provided between a second side of the cap, opposite the first side, and a second side of the housing, opposite the first side, to releasably secure the cap in the closed position, wherein the catch assembly comprises a spring latch part secured in a channel at the second side of the housing, the spring latch part having first and second end pins and a spring between the first and second end pins, the spring biased to extend the first and second end pins beyond the respective ends of the channel, the catch assembly further comprising opposing first and second catch arms extending from the second side of the cap arranged to cooperate respectively with the first and second end pins of the spring latch part as the cap is pivoted about the hinge to the closed position, the first and second catch arms each having a respective inwardly facing recess in which the respective end pins of the spring latch part are received when the cap is moved to the closed position.