wullewuu
2022-09-10 21:59:02
- #1
Hello,
for our new building we have installed an 8000-liter concrete cistern in the garden. Unfortunately, our property is below the backwater level, so we are initially required to secure everything against backflow. Regarding the single-family house, this is done by a Staufix FKA. Now, in our municipality, there is a combined sewer, meaning that theoretically even sewer water/fecal-containing water could flow back into the cistern. The cistern is 1.2 m below the single-family house, so even if it were to overflow, it would definitely not matter for the house. However, the neighbor would not be so pleased. Strictly speaking, I would also have to secure the cistern electronically against backflow, but honestly, that's too much for me.. the one electronic backflow prevention already annoyed me enough :D The probability of backflow there is anyway so low, but whatever.. that should not be the topic. I now want to secure the cistern at least with a double flap (e.g., Staufix from Kessel). But I keep wondering how to best implement this. The company Finger (cistern manufacturer) sent me the attached document about this. From this, I see two problems/questions: 1. In this position, the backflow valve is practically not accessible, neither for maintenance nor for emergency closure. 2. The backflow valve is below the water surface, assuming the cistern is full. Can that be correct? My idea would be to extend the outlet pipe inside, then the whole system would at least be closer to the center, but it would also become less stable.. Or is it no problem if the flap is essentially underwater?
for our new building we have installed an 8000-liter concrete cistern in the garden. Unfortunately, our property is below the backwater level, so we are initially required to secure everything against backflow. Regarding the single-family house, this is done by a Staufix FKA. Now, in our municipality, there is a combined sewer, meaning that theoretically even sewer water/fecal-containing water could flow back into the cistern. The cistern is 1.2 m below the single-family house, so even if it were to overflow, it would definitely not matter for the house. However, the neighbor would not be so pleased. Strictly speaking, I would also have to secure the cistern electronically against backflow, but honestly, that's too much for me.. the one electronic backflow prevention already annoyed me enough :D The probability of backflow there is anyway so low, but whatever.. that should not be the topic. I now want to secure the cistern at least with a double flap (e.g., Staufix from Kessel). But I keep wondering how to best implement this. The company Finger (cistern manufacturer) sent me the attached document about this. From this, I see two problems/questions: 1. In this position, the backflow valve is practically not accessible, neither for maintenance nor for emergency closure. 2. The backflow valve is below the water surface, assuming the cistern is full. Can that be correct? My idea would be to extend the outlet pipe inside, then the whole system would at least be closer to the center, but it would also become less stable.. Or is it no problem if the flap is essentially underwater?