takeman
New Member
Our basement had 9 inches of sewage flooding in 2013.
We finally had a plumber install a backwater valve - Mainline Fullport 4" Normally Open. As installed, the valve body measured at the lid has zero slope.
While nothing was flowing through the backwater valve, out of curiosity, I lifted the gate by hand. When the gate was almost vertical, with about 2" gap at the top of gate, it pulled itself shut! It's as if there is negative air pressure in the lateral connected to the inlet of the valve.
Is it possible that there is negative air pressure in the lateral? Why or how? Is this a problematic condition?
With the valve gate open, when I flush a toilet, the water shows up trickling through the valve within seconds.
But, with the valve gate closed, the gate doesn't open when I flush a toilet. It opens only 3-5 minutes after I let a faucet run continuously. The gate seems to open only after a significant amount of water "backs up" upstream. This happens with nothing in the drain downstream of the valve, with the cleanout closed or opened.
I wonder if this behavior - the valve gate not opening immediately - will lead to problems during normal usage. Will the valve gate shut too often, with minimal rainfall - leading to basement flooding not with city sewage, but with effluent from our own house?
Your comments please.
We finally had a plumber install a backwater valve - Mainline Fullport 4" Normally Open. As installed, the valve body measured at the lid has zero slope.
While nothing was flowing through the backwater valve, out of curiosity, I lifted the gate by hand. When the gate was almost vertical, with about 2" gap at the top of gate, it pulled itself shut! It's as if there is negative air pressure in the lateral connected to the inlet of the valve.
Is it possible that there is negative air pressure in the lateral? Why or how? Is this a problematic condition?
With the valve gate open, when I flush a toilet, the water shows up trickling through the valve within seconds.
But, with the valve gate closed, the gate doesn't open when I flush a toilet. It opens only 3-5 minutes after I let a faucet run continuously. The gate seems to open only after a significant amount of water "backs up" upstream. This happens with nothing in the drain downstream of the valve, with the cleanout closed or opened.
I wonder if this behavior - the valve gate not opening immediately - will lead to problems during normal usage. Will the valve gate shut too often, with minimal rainfall - leading to basement flooding not with city sewage, but with effluent from our own house?
Your comments please.