Verification procedure
All products installed in a drainage system are classified as construction products and must comply with building regulations in accordance with the Construction Products Directive, the State Building Regulations and DIN 1986-100. The following methods of verification are permitted for this purpose:
- harmonised standards such as DIN EN 12050 for lifting stations or DIN EN 13564 for backwater valves
- general building authority approvals, such as Z-53.2-487 for the Ecolift backwater lifting station
- approval in individual cases following a suitability assessment and consultation with a competent authority
With regard to the scope of application, DIN 1986-100 describes only the two standardised product types: lifting stations and backwater valves. However, as the commentary on DIN 1986-100 also notes, for reasons of technical development, cost-effectiveness, but also environmental protection and the economical use of primary energy sources, it is necessary for new construction materials, components, designs and fixtures to be applied and used. In this respect, innovative solutions may also be planned and used. Their scope of application is regulated in the relevant approval or must be agreed with the relevant authority on a case-by-case basis.
Product types for backwater protection
There are therefore three main types of product available to protect against backwater:
- automatic sewage lifting units with backwater loop in accordance with DIN EN 12050
- Backwater valves in accordance with DIN EN 13564-1
- Backflow prevention systems with general building authority approval, e.g. backwater pumping stations, backwater lifting stations and hybrid lifting stations
How the products work
The different product types vary in terms of their design, including backwater valves, pumps and backwater loops. Backflow pump and hybrid lifting stations thus combine the design features of backwater valves and lifting stations. This also results in significant differences in how they operate. Consequently, in addition to established and standardised products, innovative products are also available for project planning. In most cases, depending on the specific situation, there are several options available. When making the final decision, the choice should therefore be based on the optimum balance of safety and cost-effectiveness.
Use and selection of backwater valves
Backwater valves may be subject to restrictions due to local or national regulations. Only the following types may be used in Germany:
type of wastewater | Type |
| Greywater (water without sewage): | Types 1*, 2 and 5 |
| Black water (sewage with sewage): | Type 3 only, marked ‘F’ |
* The overflow from an underground storage tank can be protected by a type 1 backwater valve if it is connected to a rainwater drain.
