An individual sewer system in a country house, as a rule, is arranged on a non-pressure basis. Drains are sent to the septic tank by gravity under a slope. If, for a number of reasons, it is not possible to build such a collector, sewage under pressure is necessary. Such a system forcibly sends drains to the collection point using a special pump.
The device and purpose of pressure sewer
Pressure sewer is an almost identical system with a gravity collector. The difference between them is the presence of a pumping station (sewage pumping station) in one of the sections of the pipeline. As a rule, it is located at the lower point of the collector so that in the future the pump sends effluents to the receiver or to the gravity section of the system.
KNS works as a compulsory device for moving wastewater to a receiver and as a storage device for fecal matter. If a certain level of contaminated water accumulates in the tank, the pump switches on and transports sewage further to the septic tank or central collector.
Forced sewage is needed in such cases:
- a complex rocky relief of the site, which does not allow laying sewer pipes under a given slope or a complex trajectory of their installation and, as a result, stagnation of sewage on stretches of track;
- construction of a house at the lowest point of the relief site and the location of the central collector above its level;
- the need to install a sewer system from pipes of small cross-section;
- installation of the pipeline by an open method (above the road).
Often, for the installation of pressurized sewage in a private house, a mini HPS (special pump) is installed in the basement floors of cottages immediately after the toilet. Thus, effluents under pressure reach a gravity section of individual sewage. Small stations are called house buildings. External pumping stations are mounted outside the house and can serve several objects at once.
Advantages and disadvantages
Pressure sewer system has several advantages:
- With its device, you can safely use pipes of a smaller cross-section than the non-pressure system requires. This somewhat reduces the cost of the collector installation process.
- When laying pipes, there is no need to clearly monitor the level of their slope.
- Blockages in the sewer system in the presence of SPS are extremely rare.
The disadvantages of pressure sewer include:
- the high cost of KNS, especially if it is external;
- the need to install damping wells to relieve excessive pressure in the system (for stations serving several houses);
- installation and maintenance costs of the pump station.
With a properly installed pump, the sewer system will work without interruption for decades. You only need to clean the main tank regularly.
Current requirements
When installing the pumping station, it is important to observe specific rules:
- KNS is mounted only in rooms with a positive temperature. If it is an outdoor station, it is qualitatively insulated.
- When designing the system, it should be borne in mind that approaches to the pump should be open from all sides, and the site should accommodate the foreman in case of repair / maintenance work.
- The collector from the pump to the sink receiver is made without sharp turns and distortions.
- A special support bend for sewer pipes is installed at the bottom of the pumping station.
- The tubes for the pressure manifold must be flexible, have good linear tension, withstand pressure drops and provide reliable tightness at the joints.
- According to SNiP, the collector of the outer part of the sewage system is laid below the level of freezing of the soil or it is well insulated.
- To prevent reverse sewage current, a valve and a check valve are installed.
If the installation of a combined sewage system is provided, pipes under pressure are installed after the pump. Before it is possible to install conventional tubes.
Pipe selection
For the construction of a sewage system operating under pressure, it is necessary to use pipes that meet the following characteristics:
- good flexibility;
- resistance to pressure drops;
- increased tightness at the joints.
Cast iron and polymer pipes have such properties. The former are used not so often because of the large mass, relative fragility in the cold, and the complexity of their installation.
An excellent option for mounting pressure sewer are PVC pipes or HDPE. They differ in such advantages:
- inertness of the material to aggressive environments;
- light weight;
- the smoothness of the inner walls, which prevents siltation of the collector / sticking to its walls of fecal waste.
Polymer pipes are joined by a simplified connection technology.
Installation Steps
Work on the installation of KNS is performed in the following sequence:
- Determine the installation location of the pump. As a rule, it is mounted at the lowest point of the sewer collector.
- The fasteners included with the pump are installed on the prepared site.
- Mount the device itself and check the reliability of its position. SPS should stand straight, without distortions and forced turns relative to the input / output of the collector.
- The rubber hoses included in the kit are connected to the pump inlet / outlet.
- Hoses are joined with manifold pipes using special fittings.
- All joints are additionally treated with sealant.
- The assembled system is connected to electricity.
The KNS drive must have some spare volume in case of a power outage. It is good if this volume allows the accumulation of effluents for at least three days, or you need to install an autonomous generator in the house.
