Sewage installations - Bypass ventilation

Product	InstalSystem 5
Type of article	SAMPLE PROJECT
Source for translation	2026-06-23

Project description

The attached projects present an exemplary solutions for a sewage installation with bypass ventilation.
Schemes A-D are applicable to buildings from 3 to 5 floors (less or equal to 12m in height).
Schema E - for the buildings with more than 5 floors (more than 12m in height).

Files to download and project information

Schema A

• Direct parallel ventilation: vent stack is connected to the sewage stack at the bottom near the stack foot, and at the top to the vent pipe;
• Generate intermediate ventilation connections can be made or not depending on the project features.
  

  File:Sewage installations Bypass ventilation Schema A.png

  1. Schema A.

  
  Bypass ventilation Schema A, isproj
  

Schema B

• Indirect parallel ventilation: vent stack is a separate one, and is connected to the branches on each floor. Horizontal ventilation pipes are to be drawn manually, correcting the elevation where necessary;
• Air admittance valve is used as an Element on top of stack for both stacks (Sanitary drainage and Ventilation conduit).
  

  File:Sewage installations Bypass ventilation Schema B.png

  2. Schema B.

  
  Bypass ventilation Schema B, isproj
  

Schema С

• Direct parallel ventilation: vent stack is connected to the sewage stack at the bottom near the stack foot and at the top to the vent pipe;
• Generate intermediate ventilation connections are made automatically;
• Connection to the vent stack from each fixture on the first floor and from each sewage branch on the floors above.
  

  File:Sewage installations Bypass ventilation Schema С.png

  3. Schema C.

  
  Bypass ventilation Schema C, isproj
  

Schema D

• Air admittance valve is used on the first floor for the most distant fixture;
• Drainage ventilating pipe-run are connected to the sewage stack on the floors above.
  

  File:Sewage installations Bypass ventilation Schema D.png

  4. Schema D.

  
  Bypass ventilation Schema D, isproj
  

Schema E

• In high buildings the fixtures on the lowest floors should be connected to the additional sewage pipe in the stack;
• The additional sewage pipe should be connected to the sewage collector at least 2 m from the base of the stack;
• Generate intermediate ventilation connections is declared as well;
• The connection of the additional stack to the main stack is made by the means of a "vent loop". For more information, see: Creating pressure-relief loops in high-rise stacks of sanitary sewage installations.
  

  File:Sewage installations Bypass ventilation Schema E.png

  5. Schema E.

  
  Bypass ventilation Schema E, isproj

If you have any comments on this article, please send us a short message at info@instalsoft.com.