TITLE 77: PUBLIC HEALTH
PART 890 ILLINOIS PLUMBING CODE
CHAPTER I: DEPARTMENT OF PUBLIC HEALTH
SECTION 890.1420 STACK VENTS, VENT STACKS, MAIN VENTS
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Section 890.1420  Stack Vents, Vent Stacks, Main Vents

 

a)         Design.  A properly designed and installed venting system, in conjunction with the soil or waste system, is essential to protect trap seals and prevent siphonage, aspiration, or back pressure.  The venting system shall be designed and installed to permit the admission or emission of air so that under normal and intended use the seal of any fixture trap shall never be subjected to a pneumatic pressure differential of more than a one (1) inch water column.  If a trap seal is subject to loss by evaporation, means shall be provided to prevent loss of the trap seal. (See Section 890.410(f).)

 

b)         Installation.  A stack vent, vent stack or a main vent shall be installed with a soil or waste stack whenever back vents, relief vents, or other branch vents are required.  (See Appendix K: Illustration A.)

 

c)         Terminal.  Vents shall terminate independently above the roof to the outside atmosphere, or shall be connected to another vent at least six (6) inches above the flood-level rim of the highest fixture.  (See Appendix K:  Illustration B.)

 

d)         Main Stack.  Each building in which plumbing is installed shall have at least one main vent stack no smaller than three (3) inches for each building drain installed.  (See Appendix A:  Table K, and Appendix K:   Illustration C.)

 

e)         Building Sub-drain Sump Vent Sizes.  Building sub-drain sump vents shall be sized in accordance with Appendix A:  Table K.

 

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