Studor Mini-Vent Air Admittance Valve for 1-1/2 & 2

The unique design of the STUDOR MINI-VENT provides plumbing ventilation to prevent the loss of water seals in traps without the need for costly roof penetration and vent piping.

• The Studor Mini-Vent is made of white PVC
• Studor Mini-Vent Model #SMV fits 1-1/2 in. & 2 in. pipe sizes - Studor Mini-Vent includes a glue socket adaptor to 1 1/2 & 2 in. PVC
• Studor packaging provides extra protection for the Studor Mini-Vent from extreme temperatures, debris, and tampering when used in installation.
• Can be used as an individual, branch, circuit or stack vent
• Will vent up to 160 DFUs on a branch
• Will vent up to 24 DFUs on stack
• Expands architectural design limits
• Reduces the number of fire-stopping applications
• Exclusive vermin protection system
• Any plumber knows that the Studor Mini-Vent is IT when you just can't hit the roof!
• Studor Mini-Vent has a lifetime warranty.
• Studor Mini-Vent is made in the USA

Studor SMV is also known as the Studor Mini-Vent, Studor Mini, Studor Vent, Quick Air Admittance Valve and BOCA in-line vent, because it conforms with the B.O.C.A. (Building Officials and Code Administrators International) Code, which is the National Standard Plumbing Code.

How Air Admittance Valves (AAV) Works

The purpose of venting plumbing is to allow air to enter the plumbing drainage waste and vent piping system and equalize pressure when water drains out of the system maintaining the integrity of the water trap seals that prevents sewer gases from entering the building through fixture drains. Air Admittance Valves open and close in conjunction with normal (DWV) Drain Waste and Vent, plumbing system operation. When a plumbing fixture is operated a negative pressure (induced by fixture discharge) causes the AAV to open and allow air to enter the DWV system. The air equalizes the pressure within the system, protecting traps and eliminating the chance of siphonage - at no time is drainage flow disturbed. The time it takes for an AAV to open is extremely short, assuring that it responds to system needs. Static or positive pressure closes the AAV, eliminating sewer gas from entering the building.

The Studor AAV can be used in lieu of expensive and complex plumbing (open pipe) vent systems that penetrate roofs of buildings.

A plumbing drainage venting system is the component of a drainage system that maintains neutral pressure in the pipework, allowing flow of water down drains and through waste pipes. Venting also removes foul or combustive gasses from the system, usually through vents located above a building's roof.

The abbrieviations "DWV" (drain waste vent) and "SVP" (soil & vent pipe) refer to the piping of a building's complete drainage system.

Venting is important to prevent pressure differentials in the drainage system.

A sewer pipe is normally at neutral pressure compared to the surrounding atmosphere. When a column of waste water flows through a pipe, it compresses air in the pipe, creating a positive pressure that must be released or push back on the waste stream. As the column of water passes, air must flow in behind the waste stream or negative pressure (suction) results. The extent of these pressure fluctuations is determined by the fluid volume of the waste discharge.

Excessive negative air pressure can siphon water from trap seals at sanitary appliances (such as the p-trap under a sink). Generally, a toilet outlet has the smallest trap seal, making it most vulnerable to being emptied by induced siphonage. An empty trap can allow noxious sewer gasses to enter the interior of a building.

On the other hand, if the air pressure within the drain becomes suddenly higher than ambient, this positive transient could cause serwage waste water to be forced into a plumbing fixture or appliance, breaking the trap seal, with dire hygiene and health consequences. Tall buildings are particularly susceptible to this problem.

To prevent the problems of high pressure in a drain system, sewer pipes will usually vent via one of several mechamisms.

Most residential buildings in North America are vented directly to the roof. The pipe is typically ABS or PVC DWV-rated plastic pipe equipped with a flashing to prevent water entering the roof cavity. Older homes may use copper, iron, lead or clay pipes (in rough order of increasing antiquity).

Under many building codes, a vent "stack" (or pipe leading to the main roof vent) are required to be within a five foot radius of the draining fixture (sink, toilet, shower stall, etc.). To allow only one vent stack (and thus roof protrusion) - as permitted by local building code - sub-vents may be tied together and exit a common vent stack.

A blocked vent is relatively common, caused by anything from leaves to dead squirrels. Symptoms range from bubbles in the toilet bowl when it is flushed, slow drainage, and all the way to siphoned (empty) p-traps and sewer gases entering the home.

Air Admittance Valve

An Air admittance Valve (AAV) allows air to enter the plumbing drainage system through a one-way air valve when a plumbing fixture is operated and water flows through the pipes. When the flow stops, the valve closes by gravity and prevents the escape of sewer gas from the plumbing system. AAVs allow greater freedom of design for plumbers, engineers and architects.

Additional Documentation on the Studor Mini-Vent

Mini-Vent Specification Sheet
Mini-Vent Sell Sheet

Thank your plumber - "Plumbers Protect The Health Of The World."

About Pipe Sizes: IPS, NPS,

Below is an edited and modified exerpt only about pipe sizes, for complete information see Wikipedia:

Nominal Pipe Size (NPS) is a set of standard pipe sizes used for pressure piping in North America. The same pipe dimensions are used with different names in Europe. It is often incorrectly called National Pipe Size, due to confusion with National pipe thread.

Pipe size is specified with two non-dimensional numbers: a Nominal Pipe Size (NPS) and a schedule (SCH). The relationship of these numbers to the actual pipe dimensions is a bit strange. The NPS is very loosely related to the inside diameter in inches, but only for NPS 1/8 to NPS 12. For NPS 14 and larger, the NPS is equal to the outside diameter (OD) in inches. For a given NPS, the OD stays constant and the wall thickness increases with larger SCH. For a given SCH, the OD increases with increasing NPS while the wall thickness increases or stays constant. Pipe sizes are documented by a number of standards, including API 5L, ANSI/ASME B36.10M in the US and ISO 65 international.

NPS 1/8" to NPS 3-1/2"

 NPS 4"

 Excerpt about Pipe Size Information - Credit to Wikipedia: and the following references:

- Thank you.

1. Oberg, Erik; Franklin D. Jones, Holbrook L. Horton, and Henry H. Ryffel (2000). in ed. Christopher J. McCauley, Riccardo Heald, and Muhammed Iqbal Hussain: Machinery's Handbook, 26th Edition, New York: Industrial Press Inc.. ISBN 0-8311-2635-3. 
2. Nayyar, P.E., Mohinder L. (2000). "A1", in Mohinder L. Nayyar, P.E.: Piping Handbook, 7th, New York: McGraw-Hill. ISBN 0-07-047106-1. 
3. Engineering Department (1988). Flow of Fluids Through Valves, Fittings, and Pipe (Technical Paper No. 410), 25th Printing—1991, Joliet, IL: Crane Co.. 
4. ANSI/ASME Standard 36.19M - Stainless Steel Pipe. 
5. ANSI/ASTM Reference R0036 - Stainless Steel Pipe.