Uniform Plumbing Code Chapter 9: Vents

Questions and Answers

Vent pipes protect fixture traps against...

siphonage

Traps serving sinks that are part of the equipment of bars, soda fountains, and counters need to be vented.

False

One factor for determining the size of a vent pipe is...

its length

The combination of vent pipes that will provide sufficient aggregate cross sectional vent area for a required 4 inch house sewer is...

4-2 inch Signup and view all the answers

The maximum horizontal length permitted for a required 2 inch vent pipe is...

120 ft Signup and view all the answers

The diameter of an individual vent shall not be less than...

1 1/4 inch Signup and view all the answers

The minimum distance a vent must rise above the flood level rim of the fixture it serves before it may offset horizontally is...

6 inches Signup and view all the answers

A 2 inch vent pipe will serve how many lavatories?

24 Signup and view all the answers

Each vent pipe or stack shall extend through its flashing and shall terminate vertically above the roof at least...

6 inches Signup and view all the answers

Each vent pipe or stack shall be located at least how far away from a vertical surface?

12 inches Signup and view all the answers

Horizontal termination of vents from any openable window, door opening, air intake, or vent shaft shall be not less than...

10 feet Signup and view all the answers

Joints at the roof around vent pipes shall be made water tight by the use of...

approved flashings or flashing material Signup and view all the answers

Except for alleys and streets, vent termination from property lines shall not be less than...

3 feet Signup and view all the answers

Vents terminating in roof areas used for sun bathing shall be extended above the roof at least...

7 feet Signup and view all the answers

Parallel vent stacks are required for drainage stacks that extend above the building drain...

10 stories or more Signup and view all the answers

The parallel vent stack shall be connected to the drainage stack by means of a...

yoke vent Signup and view all the answers

The pipe size for the common vent serving lavatories installed back to back shall be not less than...

1 1/2 inch Signup and view all the answers

Horizontal drain pipes shall be level or so graded as to drip back by gravity to the...

drainage pipe it serves Signup and view all the answers

The minimum size vent pipe that may serve a 4 inch trap is...

2 inch Signup and view all the answers

Increasing vents one pipe size will...

allow vents of length Signup and view all the answers

Changes in direction of vent piping shall be made by...

appropriate use of approved fittings Signup and view all the answers

A drainage stack extends 14 stories above the building drain and is served by a parallel vent stack. A relief yoke vent connection between the vent stack and the drainage stack is required at floors...

9 and 4 Signup and view all the answers

The fitting that is required for making the yoke vent intersection with the drainage stack is a...

wye branch fitting Signup and view all the answers

The size of the yoke vent shall be...

not less in diameter than either the drainage or the vent stack, whichever is smaller Signup and view all the answers

If, due to structural conditions, horizontal vents are less than 6 inches above the overflow rim of the fixture, the horizontal portion shall be installed with...

approved drainage material and fittings and grade to drain Signup and view all the answers

Vent terminals in locations having minimum design temperatures below 0 degrees F shall be a minimum of...

2 inches Signup and view all the answers

Copper tube shall not be used for...

chemical or industrial wastes Signup and view all the answers

ABS or PVC DWV piping installations exposed within ducts or plenums shall be limited to a flame spread index of not more than 25 or a smoke index of 50 except for...

individual single family dwelling units Signup and view all the answers

Sheet lead used for flashings of vent terminals shall be not less than _______ pounds per square foot.

3 ppsf Signup and view all the answers

In a combination waste and vent system, the size of the trap arm must be increased by...

two pipe sizes Signup and view all the answers

The minimum size drain to supply to a kitchen island sink is...

2 inch Signup and view all the answers

The maximum length a combination waste and vent system branch can go horizontally without being separately vented is...

15 feet Signup and view all the answers

A 2 inch floor drain connected to a combination waste and vent system must be connected to a drain pipe at least...

3 inches Signup and view all the answers

The area of a vent installed in a combination waste and vent system shall be not less than...

one half the inside cross sectional area of the drain pipe served Signup and view all the answers

Long mains shall be provided with relief vents at intervals of...

100 ft Signup and view all the answers

The connection from a waste line to a vent shall be...

down stream of the upper most fixture Signup and view all the answers

Water closets, bathtubs, showers, and floor drains within one or two bathrooms located on the same floor level for private use shall be permitted to be vented by a...

wet vent Signup and view all the answers

Horizontal wet venting is...

allowed for two bathrooms in a dwelling or guest room on the same floor Signup and view all the answers

The fixture that serves as a dry vent connection to the horizontal wet vent is a...

lavatory, urinal, shower, or bidet Signup and view all the answers

The vent system shall be designed to prevent a trap seal from being exposed to a pressure differential on the outlet side of the trap that exceeds _______ inch of water column.

1 inch water column Signup and view all the answers

The horizontal wet vent shall be not less than two inches in diameter for _______ drainage fixture units or less.

4 DFUs Signup and view all the answers

The dry vent connection to the wet vent shall be a ______ vent.

individual or common vent Signup and view all the answers

The _____ fixture drain or trap arm connection to the horizontal wet vent shall be downstream of the fixture drain or trap arm connections.

water closets, bathtubs, showers and floor drains Signup and view all the answers

An engineered vent system shall be designed by _______ and approved in accordance with section 301.4.

a registered design professional Signup and view all the answers

Joints at the roof and around pipes shall be made water tight by the use of...

flashing material Signup and view all the answers

Study Notes

Vent Pipe Functions and Requirements

Vent pipes protect fixture traps from siphonage, ensuring proper drainage and functionality.
Certain traps in sinks at bars, soda fountains, and counters may not require venting under specific conditions.

Sizing and Length of Vent Pipes

The length of a vent pipe is critical for determining its size; longer vents require larger diameters.
Minimum diameter for an individual vent must be 1 1/4 inches.
A 2-inch vent pipe can serve up to 24 lavatories, reflecting its capacity in drainage systems.

Vent Installation Guidelines

Vent pipes must rise at least 6 inches above the fixture's flood level before they can offset horizontally.
Maximum horizontal length for a required 2-inch vent pipe is 120 feet, ensuring effective venting across distances.

Vertical Venting Standards

Each vent pipe must extend at least 6 inches above the roof and be 12 inches from any vertical surface, preventing obstruction in airflow.
Vents must terminate 10 feet away from any openable window, door, air intake, or vent shaft to ensure air quality.

Vent Connection Requirements

Joints at the roof and around vent pipes need to be water-tight, achieved through approved flashing materials.
Minimum distance for vent termination from property lines, except alleys and streets, is 3 feet.

Special Conditions for Venting

For drainage stacks above 10 stories, parallel vent stacks are required to manage airflow effectively.
The size of the yoke vent connected to drainage stacks should not be less than the smaller of the drainage or vent stack.

Additional Specifications

Vent terminals in cold climates (below 0°F) must be at least 2 inches in diameter to withstand conditions.
Copper tube is not permitted for chemical or industrial waste due to corrosion risks.

Flashing and Connection Guidelines

Sheet lead for vent flashings must be a minimum of 3 pounds per square foot to ensure durability.
In combination waste and vent systems, the size of the trap arm should increase by two pipe sizes for proper flow.

Compliance and Management

An engineered vent system requires design by a registered professional and must adhere to established guidelines.
Wet venting allows for efficient venting between multiple fixtures within a single system, streamlining plumbing layouts.

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Description

Test your knowledge on the key concepts of venting from the Uniform Plumbing Code Chapter 9. This quiz provides flashcards that cover essential definitions and requirements related to vent pipes and trapping. Perfect for plumbing students and professionals looking to reinforce their understanding of vent systems.