Patent ID: 7475568

Claim:
A method of forming an oxide glass in a manufacturing process comprising: flowing a glass melt having a β —OH concentration of at least about 0.35 mm −1 through a vessel comprising a metal selected from the group consisting of platinum, gold, molybdenum, palladium, rhodium, iridium, rhenium, tantalum, titanium, tungsten, and alloys thereof, there being an interface present between the vessel and the glass, the vessel further comprising a first portion and a second portion; controlling a partial pressure of hydrogen of a first atmosphere in contact with an outside wall surface of the vessel first portion in an amount such that hydrogen permeation blisters form in a region of the glass adjacent the glass-vessel interface in the vessel first portion; and controlling a partial pressure of hydrogen of a second atmosphere in contact with an outside wall surface of the vessel second portion in an amount such that hydrogen permeation blisters are substantially prevented from forming in a region of the glass adjacent the glass-vessel interface in the vessel second portion.