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Automatic Air Valves - For All Hot Water and Solar Heating Systems

Correct problems and avoid trouble by installing these float-operated Auto-Vents. They vent air from mains, solar panels, pipe lines, boilers, unit heaters, chillers, convectors, radiant panels, coils, baseboard and free-standing radiation.

Please choose an Auto-Vent®: 7 Series66, 67, 68 & Accessories27 & 377295



No. 7 Series Auto-Vents®

The No. 7 Series Auto-Vents® are reliable, automatic air eliminating valves for concealed radiators, pipe lines, tanks and other devices where water or liquids are used for heating and cooling. They have proven to be the solution to problems that have confronted engineers and contractors in which air pockets or traps retard the free circulation of the liquids and reduce the efficiency of the system or appliance. The No. 7 Series Auto-Vents® air eliminators are made of brass and equipped with a self-closing, float-operated valve. The valve is equipped with a Monel® metal spring and a Neoprene® valve seat which is unaffected by high temperatures, oil and anti-freeze. No air chamber is required. The vent is regularly fitted with a patented cap that may be used as a check in case of a leak caused by core sand or scale.

No. 7 Auto-Vent®
No. 7 Auto-Vent®
  • Vertical mounting
  • 1/8" I.P. female connection
  • 75 lbs. pressure
  • 4 3/8" x 2 1/4"
  • Bright brass finish
No. 71 Auto-Vent®
No. 71 Auto-Vent®
  • Vertical mounting
  • 1/4" I.P. male connection
  • 150 lbs. pressure
  • 4 3/8" x 2 1/4"
  • Bright brass finish
No. 74 Auto-Vent®
No. 74 Auto-Vent®
  • Vertical mounting
  • 1/4" I.P. female connection
  • 150 lbs. pressure
  • 4 3/8" x 2 1/4"
  • Bright brass finish
No. 75 Auto-Vent®
No. 75 Auto-Vent®
  • Combination connection 
  • 1/2" female & 3/4" male
  • Up to 150 lbs. pressure
  • 4 3/4" x 2 1/4"
  • Bright brass finish
No. 77 Auto-Vent®
No. 77 Auto-Vent®
  • Vertical mounting
  • 1/8" I.P. female connection
  • 1/8" female side opening 
  • 75 lbs. pressure
  • 4 3/8" x 2 1/4"
  • Bright brass finish
No. 78 Auto-Vent®
No. 78 Auto-Vent®
  • Vertical mounting
  • 1/8" I.P. male connection
  • 75 lbs. pressure
  • 4 3/8" x 2 1/4"
  • Bright brass finish

Applications of No. 7 Series Auto-Vents®

Auto-Vent® Applications for Solar Heating
Applications for Solar Heating
Auto-Vent® Applications for Trapped Mains and Circulating Lines
Applications for Trapped Mains and Circulating Lines
Auto-Vent® Applications for Boiler or Chilling Units
Applications for Boiler or Chilling Units
Auto-Vent® Applications for Trapped Mains and Circulating Lines
Applications for Trapped Mains and Circulating Lines
Auto-Vent® Applications for Trapped Mains and Circulating Lines
Applications for Trapped Mains and Circulating Lines




No. 66, 67, 68 Auto-Vents® and Accessories

The No. 66, 67, 68 Auto-Vents® are float-operated vents for use on convector radiators, baseboard radiation and radiant panels. These are designed to be used in space that is limited and can be installed in trouble spots previously neglected or improperly vented. No air chamber is required. The No. 66, 67, 68 Auto-Vents® are designed for systems with pressures up to 50 lbs.

The No. 9AS Shortstop is an Automatic Shut-Off that saves hours when changing out Maid-O’-Mist® vents with 1/8” male connections. This accessory is a spring-loaded shut-off that stops the flow of water automatically when the vent is removed and re-opens when a new Maid-O’-Mist® vent is installed. With a Shortstop in place, it is no longer necessary to drain the system to switch out vents.

In situations where safe waste is required by law or areas particularly susceptible to water damage, the No. 7A Connector is used to connect 1/4” copper or plastic tubing to the venting port of Maid-O’-Mist® vents. In this manner, any spray caused at system start-up or leaking caused by scale in a system can be safely directed to a drain.

No. 66 Auto-Vent®
No. 66 Auto-Vent®
  • Vertical mounting
  • 1/8" I.P. male connection
  • Up to 50 lbs. pressure
  • 2 5/8" x 1 1/4"
  • Bright brass finish

No. 9AS Shortstop Automatic Shut-off for use with No. 66, 67 and 78 Auto-Vents®
No. 9AS Shortstop Automatic Shut-off for use with No. 66, 67 and 78 Auto-Vents®.
No. 67 Auto-Vent®
No. 67 Auto-Vent®
  • Vertical mounting
  • 1/8" I.P. male connection
  • Up to 50 lbs. pressure
  • 3 3/4" x 9/16"
  • Bright brass finish
No. 68 Auto-Vent®
No. 68 Auto-Vent®
  • Vertical mounting
  • 1/4" I.P. male connection
  • Up to 50 lbs. pressure
  • 4" x 1 9/16"
  • Bright brass finish

Applications of No. 66 and No. 67 Auto-Vents®

No. 7A Connector for Safe Waste
No. 7A Connector for Safe Waste.
Auto-Vent® Applications for Venting Convector Radiators
Applications for Venting Convector Radiators
Auto-Vent® Applications for Venting Baseboard Radiators
Applications for Venting Baseboard Radiators




No. 27 and 37 Auto-Vents®

The No. 27 and 37 Auto-Vents® are dependable float-operated valves. Their construction and internal working parts are the same as the No. 7 Series Auto-Vents® except smaller in size. Made of non-ferrous metals.

No. 27 Auto-Vent®
No. 27 Auto-Vent®
  • Horizontal mounting
  • 1/8" I.P. female side connection
  • 50 lbs. pressure
  • 3" x 2 1/2"
  • Bright brass finish

Applications for No. 27 and No. 37 Auto-Vents®

No.37 Auto-Vent® Installed on Convector Radiator
No.37 Auto-Vent® Installed on Convector Radiator

No.27 Auto-Vent® Installed on Convector Radiator
No.27 Auto-Vent® Installed on Convector Radiator

No.27 Auto-Vent® Installed on Convector Radiator
No.27 Auto-Vent® Installed on Convector Radiator

No.27 Auto-Vent® Installed on Convector Radiator
No.27 Auto-Vent® Installed on Convector Radiator
No. 37 Auto-Vent®
No. 37 Auto-Vent®
  • Horizontal mounting
  • 1/8" I.P. vertical male bottom connection
  • 50 lbs. pressure
  • 3" x 2 1/2"
  • Bright brass finish




No. 37 Auto-Vent®
No. 72 Auto-Vent®
  • Vertical or horizontal mounting
  • 1/8" I.P. male connection
  • Up to 75 lbs. pressure
  • 1 1/4" x 1/2"


No. 95 Pushbutton Manual Vent®
No. 95 Pushbutton Manual Vent®
  • Vertical or horizontal mounting
  • 1/8" I.P. male connection
  • Up to 50 lbs. pressure
  • 1 5/8" x 9/16"

No. 72 Auto-Vents®

The No. 72 Auto-Vents® is a fast venting valve of the expansion type. All expansion and contraction of the single non-porous, composition disk is confined to four vents ports. Manual venting and tight shut-off are controlled by a value cap with screwdriver slot adjustment. These valves are used for vertical or horizontal mounting on convectors, baseboard and free-standing radiators.



No. 95 Pushbutton Manual Vent®

The No. 95 Pushbutton Manual Vent® provides the easiest way ever to manually vent a radiator. You don’t need a key, coin or screwdriver. All you have to do is push on the insulated cap of the No. 95 Pushbutton Manual Vent® to release trapped air. Let go and the vent closes automatically. Great for tight spaces where vents requiring a key or coin are not practical.

Applications for No. 72 Auto-Vent® and No. 95 Pushbutton Manual Vent®

No.72 or No.95 Installed on Convector Radiators
No. 72 or No.95 Installed on Convector Radiators
No.72 or No. 95 Installed on Free-Standing Radiators
No. 72 or No. 95 Installed on Free-Standing Radiators
No.72 or No. 95 Installed on Baseboard Radiators
No. 72 or No. 95 Installed on Baseboard Radiators
No.72 or No. 95 Installed on Baseboard Radiators
No. 72 or No. 95 Installed on Baseboard Radiators
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