We have fabricated a mirror-finished, surface-seal-type gate valve with diaphragms made of silver and with independent compressed air systems for the seal diaphragms and seal bellows. The previous design had diaphragms made from an aluminum alloy and a common air system for the seal diaphragms and seal bellows. For the new design, after 9523 open/close sequences, a stainless steel bellows for the isolation plate vertical motion broke. However, this is a lifetime improvement of more than one order of magnitude over the old design. Further improvement of the bellows can lead to an even longer lifetime for the valve.