A new device that improves insulating glass reliability & solves the problem of negative effects of pressure/temperature variations on IG units has been made by Italian firm, AL7-Meipa. The Two-Way valve is inserted through a 6mm hole in the spacer frame & when the IG unit is sealed, the valve becomes an integral part of the same unit. Under normal conditions, the valve remains shut, without letting air in or out of the unit, completely sealed. However, when the difference between inner & outer pressure exceeds a range of around 80 millibars, the valve opens, thus allowing an adjustment between the two pressures. When the variation that caused the valve to open reaches a range of 25 millibars, the valve shuts & the unit is perfectly sealed again. Without the valve, an excessive pressure differential could put the IG unit under stress & cause damage.
