COUPLING FOR VACUUM-INSULATED PIPING

A coupling for connecting vacuum-insulated piping is disclosed. The coupling facilitates the detection of unwanted fluid ingress into the low pressure insulating outer portion of the vacuum-insulated piping and the detection of a leak from the central portion of the vacuum-insulated piping that is used to carry cold fluids. This is achieved by providing a first leak path from the central portion of the vacuum-insulated piping to a sensor outlet and a second leak path from the outer portion of the vacuum-insulated piping to the sensor outlet. One sensor may be used to detect unwanted fluid ingress into the low pressure insulating outer portion and also detect a leak from the central portion of the vacuum-insulated piping.