01B101-GB AUTOMATIC AIR VENT VALVES …

1 AUTOMATICDISCHARGEMANUALDISCHARGEAUTOMAT IC AIR VENT VALVESMANUAL VALVES FOR DISCHARGING AIR FROM RADIATORSMAIN FEATURESADVANTAGE OF BUILT-IN manual DISCHARGE- Provision for controlling operation of the AUTOMATIC discharge by pressing the manual discharge By holding down the manual discharge, water flows through the orifice thus facilitating cleaning of the AUTOMATIC discharge Rapid venting of air when filling the Large capacity AUTOMATIC airvent 0253025 1 0253032 Part MAXIVENT VALVES are inspectable thanks to theopening left by the cover after unscrewing it from the tank.

2 Therefore it is also possible to clean the internal parts (floatand lever) in case of ingress of foreign matter in the seal between the tank and cover is thanks to thepresence of an NBRrubber efficiency and performance of the ventmovement is ensured by the valve design features. Theseal system is designed to withstand vibrations, thereforeit is unaffected by any external opening and closing is determined by the floatmovement (up-down). When there is air in the MAXIVENT, the force of the floatweight acts on the lever which is integral with the plug,thus causing it to move down.

3 In such situation the seatis free and allows the air to be vented filling the system with water, the air entrapped inthe water circuit is pushed towards the outside via theMAXIVENT valve. As soon as all the entrapped air isdischarged, the water, entering the tank, pushes the floatup. Consequently the lever moves the plug to pressagainst the seat thus ensuring tight sealing of the MAXIVENT valve is normally installed:- In the highest point of the air separator- At the top of the columns installed in heating systems with expansion vessel- In all points where there is risk of air building up- At the top of the installation, in order to allow perfect air venting,unscrew the protective cap by at least two turns (suchcondition ensures the vent characteristics as given in theprevious diagram).

4 INSTALLATIONN ormally the MAXIVENT valve does not require to its particular size, the MAXIVENT valve findsapplication of AUTOMATIC venting of air in large size waterdistribution pipes ( distribution manifolds in thecentral system) and in all cases where it is necessary toeliminate large quantities of air from the MAXIVENT valve is provided with manual air FEATURESBodyCast iron G25 entirely coated with epoxy resinCoverCast iron G25 entirely coated with epoxy resinManual vent valveChrome-plated brass OT 58 LeverStainless steelPlugNBR rubberFloatHigh density expanded polyethyleneSealsNBR rubberCapBrass OT 58 Inlet connectionF 3/4" - 1" - 1 1/4" DIN-ISO 228/1 Outlet connectionF 3/8" DIN-ISO 228/1, brassTECHNICAL CHARACTERISTICSMax.

5 Discharge pressure6 barMax. operating pressure12 barMin. seal barMax. operating temperature115 CAir discharge rate (NL/min)Operating pressure (bar)80070060050040030020010000123456 Air discharge rate - Operating pressureOverall dimensions (mm)MXV - 3/4 - 1 - with double possibility of venting air from thesystem, either automaticallyor manually. The manual discharge alsoallows checking for correctoperation and cleaning theautomatic discharge 0250610 3/8 0250615 1/2 Part MVD but with AUTOMATIC shut-off valve 0250710 3/8 0250715 1/2 Part DUOVENT VALVES are inspectable by unscrewing thecover from the seal between the tank and cover is thanks to thepresence of an O-ring.

6 Therefore it is also possible toclean the internal parts (float and lever) in case of ingressof foreign matter in the valve. Long-term efficiency andperformance of the vent movement is ensured by thevalve design features. The seal system is designed towithstand vibrations, therefore it is unaffected by anyexternal AUTOMATIC operation, valve opening and closing isdetermined by the float movement (up-down). Whenthere is air in the DUOVENT, the force of the float weightacts on the lever which is integral with the plug, thuscausing it to move down.

7 In such situation the seat is free and allows the air to bevented outside. When filling the system with water, the airentrapped in the water circuit is pushed towards the out-side via the DUOVENT valve. As soon as all the entrapped air is discharged, the water,entering the tank, pushes the float up. Consequently thelever moves the plug to press against the seat thus ensu-ring tight sealing of the venting is actuated by pushing down button (10);this can be done by exerting a pressure on the surface,for example with a screw driver.

8 Such operation shiftshead (9) integral with O-ring (12) to a position lower thanthe seat, thus allowing air and/or water to flow alongstem. When water flows both from orifice (A) and (B),this indicates that all the air has been discharged from (comparison between manual and AUTOMATIC venting)The AUTOMATIC venting characteristics are similar to MINIVENT. The following dia-gram shows the AUTOMATIC and manual venting curves in relation to pressure,assuming a manual plug movement of mm. It is clear that the manual ventingallows an appreciable increasing in the discharge rate of DUOVENT valve is a development on the automaticMINIVENT valve.

9 In fact DUOVENThas the same func-tions as MINIVENT, it is used for AUTOMATIC venting ofair in water distribution pipes in order to avoid certainphenomena of damage (corrosion processes, cavitation)and loss of efficiency (air pockets in radiators) of theheating system, but it is provided with an additional devi-ce allowing manual air venting. The manual air vent devi-ce offers the following advantages:a) It allows checking the valve for correct operationb) It allows reducing times for discharging air from the system by increasing the discharge flow ratec) Easier cleaning of the orifice by forcing water to flowthrough it.

10 The DUOVENT MVDR valve is provided with an automa-tic shut-off valve (Art. RIA) which allows removal of thevent valve without having to empty the system. APPLICATIONAir discharge rate - Operating pressureDESIGN FEATURESBodyBrass OT 58 CoverBrass OT 58 PlugEPDM rubberSpringStainless steelCapPolyamideLeverPolyacetalFloatHig h density expanded polyethyleneSealsNBR rubberPlug headPolyacetalPlug buttonPolyacetalSpringStainless steelConnectionsM 1/4" - 3/8" - 1/2" DIN - ISO 228/1 Air discharge rate (NL/min)Operating pressure (bar) manual air venting(plug movement of mm) manual air venting8040240280320400360200160120001 234 5678 TECHNICAL CHARACTERISTICSN ominal pressure12 barMax.