Two Way Valve
AL7-Meipa SpA, after long research and experiments, has created a new device, the Two-Way valve that improves the Insulating Glass reliability and solves the very well known problem of the negative effects of pressure and temperature variations on I.G. units.
AL7-Meipa Two-Way valve is inserted through a 6mm hole in the spacer frame, when the I.G. is sealed, the valve becomes an integral part and feature of the I.G. unit.
Under normal conditions the valve remains “shut”, without letting air in or out of the unit, which is totally sealed. However, when the differential between inner and outer pressure exceeds a range of approximately 80 millibar the valve opens, thus allowing an adjustment between the two pressures. When the variation, that caused the valve to open, reaches a range of approximately ± 25 millibar the valve shuts and the unit is perfectly sealed again. We would like to emphasize that our two-way valve does not perfectly balance the I.G. unit pressure, it only allows an adjustment between inner and outer pressure.
Without the AL7-Meipa Two-Way valve, an excessive pressure differential could put the I.G. unit under stress and cause various damage, such as cracks in the glass or loosening of the sealant. These are the reasons why the Two-Way valve is a perfect solution in all those situations where the I.G. unit is produced at a certain altitude and pressure and then transported to a different one (e.g. produced at sea-level and then transported to the mountains) or when the I.G. is sealed with a certain barometrical pressure and then exposed to a different one (e.g. sealed on a sunny day, high pressure, and exposed to bad weather conditions, low pressure). It is very important to remember that, as stated in the laws of physics CHARLES and GAY-LUSSAC, the variations of the inner pressure, in a I.G. unit, are also due to the increase of the gas temperature, (even if the unit is filled with air or other GAS). Infact, the Two-Way valve has an optimal behaviour in GAS fi lled units (such as ARGON, HEXAFLUORIDE, etc.).
The AL7-Meipa SpA Two-Way valve has been tested at ift Rosenheim, in Germany, (Test Report No. 601 22579/2e of July, 06 2000) and fulfi ls the requirements according to DIN 1286 part 1.
