Studor MAXI-VENT Air Admittance Valve

Maxi-Vent® by Studor® fits piping systems of 3" (80mm) and 4" (100mm) diameters.

The Studor® Maxi-Vent® can vent up to 500 Drainage Fixture Units (DFUs) in a stack application.

The unique design of the STUDOR MAXI-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 Maxi-Vent is the top of the range AAV which protects the trap seals in the drainage system. It can be used for venting stack systems in buildings up to 10 storeys high as a standalone device - completely eliminating the requirement for a vent pipe through the roof. (In buildings with more than 10 storeys, a P.A.P.A. is also required.) Resulting in great savings by reducing the need for venting piping, the Maxi-Vent greatly improves the performance of the drainage system. The Maxi-Vent is part of the STUDOR System which can vent an entire building without the need for conventional vents.

• The Studor Maxi-Vent vent is made of white PVC
• Fits 3" and 4" pipe sizes. (to connect to 3" pipe the Studor Maxi Vent is 3" O.D. the same size as 3" Pipe Size or to connect to 4" pipe with a push into pipe - rubber gasket see our image above for gasket.)
• Studor packaging provides extra protection for the Studor Maxi-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 500 DFUs on a stack
• Expands architectural design limits
• Reduces the number of fire-stopping applications
• Exclusive vermin protection system
• Any plumber knows that the Studor Maxi-Vent is IT when you just can't hit the roof!
• Limited lifetime warranty for replacement of defective valves
• Studor Maxi-Vent is made in the USA

The STUDOR® Maxi-Vent is designed for the terminal of individual and branch vents, eliminating floor and roof penetrations.

The STUDOR® Maxi-Vent AAV:

• Reduces the need for fire stopping devices preventing the “chimney effect” in pipes, reducing the risk of fire spreading upwards between floors.
• Provides greater freedom of design for engineers, architects and design professionals.
• Protects the inner mechanism against the entrance of vermin, foreign objects and material by means of the specially designed screens.
• Eliminates the risk of water leakages through unnecessary roof and surface penetrations.
• Prevents transmission of odorous sewer gas into the building or surrounding areas.
• Is resistant to adverse weather conditions (-20°C to +60°C).
• Requires no maintenance, specially designed to resist extreme temperatures and deterioration.
• Has a lifetime warranty - equivalent to that of the drainage system in which it is installed - repeated opening and closing will not affect its sealing operation.

Studor SMV is also known as the Studor Maxi-Vent, Studor Maxi, 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.

Studor Maxi-Vent Air Admittance Valve Additional Documentation:

Maxi-Vent Specification Sheet
Maxi-Vent Sell Sheet

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.