Extension of the gravity-fed sanitary sewage system to include a pressure section

Product	InstalSystem 5
Type of article	TIP&TRICK
Source for translation	2026-09-18

Problem description

During the Designing gravity sanitary sewage installations, the situations may arise when some Sanitary Fixtures are located below the level which allows gravitational flow. In such situation Sanitary waste lifting plant elements should be used.

Solution

• Place one or several Wastewater lifting plant (domestic) elements near Sanitary Fixtures that are located too low to allow wastewaters to flow by gravity to the Sanitary sewage outlet.
  

  

  1. Wastewater lifting plant (domestic).

  
  
• Connect the Fixtures to the Sanitary waste lifting plant with the use of Gravity sewerage Pipe-run and ensure that wastewater flows by gravity to the Sanitary waste lifting plant.
  Note: Toilet bowl should be connected separately, exclusively to the inlets of Sanitary waste lifting plant designated for this purpose.
• Connect the outlet from the Sanitary waste lifting plant to the Gravity sewerage part of installation (Waste collector or Waste collector underground) with the use of Pipe-run (pressure part), imposing, where necessary, the elevations of the ends of the pressurised pipe-runs to achieve their desired vertical alignment.
  

  

  2. Pipe-run (pressure part).

  
  If necessary, use Stack of wastewater lifting system to rise to the Storey above. In turn, connect the Stack of wastewater lifting system to the Gravity sewerage part with the use of Pipe-run (pressure part), imposing, where necessary, the elevations of the ends of the pressurised pipe-runs to achieve their desired vertical alignment.
  

  

  3. Stack of wastewater lifting system.

  
  
• Directly before connection to the Gravity sewerage part, the Backflow loop (reversed siphon) should be created. The top of it should be located above the "flooding level" (usually ground level). To create the backflow loop, check ON the box Pipe-run makes the backflow loop in the Data table window and specify the Height of the backflow loop. The effect becomes visible after executing the function Check connections.
  

  

  4. Pipe-run makes the backflow loop.

  
  The same effect can be achieved by manually specifying the elevations of Pipe-run.
  Attention! It is not permitted to perform the outlet connections of Sanitary waste lifting plant together in a tree structure. If there are several such elements in the project, each should have an individual connection to the Gravity sewerage network.
• The ventilation outlet from the Sanitary waste lifting plant, which pumps sewage containing fecal matter, should be connected with the use of Ventilation conduit Pipe-run and Ventilation conduit Stack to the Vent pipe element, or to the Ventilation collector terminating in the Vent pipe.
  

  

  5. Ventilation conduit.

  
  
• Insert necessary Fittings in pressurised part.
  

  

  6. Fittings.

  
  

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