The repaired Maui gas pipe will have its final checks late on Saturday night, and if it gets the all-clear, reconnection of all businesses without gas will be able start.
Thousands of customers were disconnected after a leak was found in the pipe last Sunday. Most have been reconnected, but about 800 are still affected.
The new welding on the pipe was completed overnight on Friday night and has passed the first stage of certification.
A 24-hour cool-down period is then required before an external certifier can give the go-ahead to have gas supplies restored to customers.
Vector chief executive Simon Mackenzie says if it's given the all- clear, the remaining 800 customers will start being reconnected late on Sunday or on Monday.
Mr Mackenzie says ground movement was the most likely cause of the crack.
