Leak Testing

A vacuum box should be in such a condition as to enable the operator to consistently attain a differential pressure (vacuum in the box) of:

12 to 12.5 m (40 to 41 ft) of water.

1.3 to 2 kPa (10 to 15 mm Hg).

112 to 122 kPa (33 to 36 in. Hg).

slightly more than that required by the procedure.