A normally open backwater valve may be installed in your main drain provided certain criteria are met; i.e. distances from existing outlets in order to provide laminar flow.
A normally open backwater valve will provide for the free flow of air in your plumbing system as well as protecting you from sewer backup.
A normally closed backwater valve does not provide for the free flow of air in the plumbing system and may not be installed in the main line, however they may be used in the branch line serving the main drain.
Our certified plumbers can assist you in determining what type of valve you may need for your specific application.
A city permit and a plumbing inspection will be required on all backwater valve installations.