Rückstauklappe

Rückstauklappe is a backwater valve used in drainage systems to prevent sewage or wastewater from backing up into a building during overflows in the public sewer. It provides protection against sewer surcharges, heavy rainfall, and flood events by allowing flow in one direction while blocking reverse flow.

The device typically consists of a housing with a one-way flap or swinging gate. When wastewater flows out of the building, the flap opens to permit discharge. If pressure comes from the downstream sewer, the flap is pressed closed, preventing backflow into the building. Some designs use gravity operation, others employ a spring mechanism to ensure the valve remains closed when backflow threatens.

Rückstauklappen are installed in the main building drain or at the connection to the public sewer, often located in basements, cellars, or outside the building. They are generally designed for horizontal installation, with certain models suitable for vertical orientation depending on the pipe configuration. Materials commonly used include plastics and stainless steel, chosen for durability in damp environments.

Applications include residential, commercial, and industrial facilities, especially in areas prone to flooding or heavy rainfall. They protect basements, floor drains, and low-lying rooms from sewage backups and contribute to overall drainage reliability. They should be part of an integrated backflow prevention strategy and installed in accordance with local plumbing codes and manufacturer guidance.

Maintenance involves regular inspection for wear, proper sealing, and removal of debris that could hinder the flap’s movement. Accessibility for inspection and testing is important, and components such as seals or the flap may require replacement over time. Improper installation or neglect can reduce effectiveness.