... of aluminium or steel dies under low varying vacuum with china invention patent Vacuum varying pressure nitriding furnaces are equipment for ... , furnace tank, furnace top, cooling fan, lifter, vacuum system, intake system, temperature control system. It achieves seeping layer:0.14-0.18mm, bright ... ±5°C and rising time ≤80min., and the limit vacuum is -0.08 pa.Technical parameter Item No.Rated power ...