Automatic vacuum isolation valve network for a vacuum collection system

A vacuum collection system for evacuating waste water, the system comprising:

• a vacuum source adapted to generate a vacuum level;
• a tank having a vacuum intake in fluid communication with the vacuum source and a waste water intake;
• a main vacuum pipe connected to the waste water intake;
• and
• first and second branches, each branch including:
• a first valve located in the collection pipe, the first valve adapted to close when air pressure in the main vacuum pipe is greater than air pressure in the branch;
• and
• a shut-off valve located in the branch upstream of the first valve, the shutoff valve adapted to close in response to vacuum loss in a downstream portion of the branch, thereby isolating the branch.

A method for maintaining vacuum in a vacuum collection system comprising at least two branches in fluid communication with a main vacuum pipe maintained under vacuum when one of the branches is faulty, each branch including a first valve and a shut-off valve located downstream of the first valve, the method comprising the steps of:

• closing the first valve of each unbroken branch thereby to maintain vacuum therein;
• closing the shut-off valve of a faulty branch thereby to isolate the faulty branch from the main vacuum pipe;
• and
• opening the first valve of each unbroken branch to reestablish fluid communication with the main vacuum pipe.