Ask | Share | Grow™ - Question & Answer Community
Of the Members, By the Members, For the Members!
VacuumFurnaces.com is a Q&A community where vacuum furnace product and service suppliers connect with commercial and captive heat treaters to share their practical skills and know-how and to establish valuable relationships around niche topics of expertise with vacuum furnace end-users in operations, production, training, maintenance, marketing, sales, and engineering.
What is the difference between a leak rate and rate of rise?
If I understand the question, I believe the answer is they are the same. In the vacuum furnace industry, when we say "leak rate", we typically are measuring pressure as it rises to provide an indication of the in leakage of gasses into the vessel or furnace. This rise in pressure is called the "raRead more
If I understand the question, I believe the answer is they are the same. In the vacuum furnace industry, when we say “leak rate”, we typically are measuring pressure as it rises to provide an indication of the in leakage of gasses into the vessel or furnace. This rise in pressure is called the “rate of rise” when referenced over a period of time.
See lessHow to calculate rate of rise for leak check?
Pump the chamber down as far as practically possible, close the vacuum valve and measure the pressure rise over a period of time. Typically a rate of rise or leak rate is measured in a one (1) hour time period. If for example the pressure rises from 50 microns to 100 microns in one hour the rate oRead more
Pump the chamber down as far as practically possible, close the vacuum valve and measure the pressure rise over a period of time. Typically a rate of rise or leak rate is measured in a one (1) hour time period. If for example the pressure rises from 50 microns to 100 microns in one hour the rate of rise is 50 microns per hour. In other words you could say the leak rate is 50 microns per hour.
See lessHow frequently should leak testing be performed on vacuum furnaces?
Maybe once or twice a year, depending on many things. I recommend taking a leak rate (rate of rise test), after the furnace hot zone has been through a burn-out and cooled under vacuum, on a routine basis. This should be done maybe weekly or at least monthly and recorded. Eventually you will beginRead more
Maybe once or twice a year, depending on many things.
I recommend taking a leak rate (rate of rise test), after the furnace hot zone has been through a burn-out and cooled under vacuum, on a routine basis. This should be done maybe weekly or at least monthly and recorded. Eventually you will begin to see trends as the leak rate deteriorates. When the leak rate is determined to be to high, I would recommend a helium leak test using a mass spectrometer.
See lessHow to clean vacuum seals for vacuum furnace?
I would suggest using rubbing alcohol and a clean lint free rag.
I would suggest using rubbing alcohol and a clean lint free rag.
See lessWhat is an acceptable leak rates for o-rings?
An o-ring should not leak when tested with a helium mass spectrometer in the range of 10-6 or 10-7 Torr. Acceptable leak rates would be subjective and relate to the materials being processed in the furnace and the hot zone deterioration that can be tolerated with a leaking o-ring or system.
An o-ring should not leak when tested with a helium mass spectrometer in the range of 10-6 or 10-7 Torr. Acceptable leak rates would be subjective and relate to the materials being processed in the furnace and the hot zone deterioration that can be tolerated with a leaking o-ring or system.
See less