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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.
How do you perform a helium leak test on a vacuum furnace?
Finding leaks in vacuum furnaces is a task that few people look forward to, however it is important and necessary. Leaks happen almost always and can occur suddenly or develop over time. They can damage both the material being heat treated as well as internal furnace components. When left uncheckedRead more
Finding leaks in vacuum furnaces is a task that few people look forward to, however it is important and necessary. Leaks happen almost always and can occur suddenly or develop over time. They can damage both the material being heat treated as well as internal furnace components. When left unchecked leaks will stop the furnace from pumping down and will compromise the heating elements. Small leaks often go undetected since the pumping system can overcome them, but they can still cause continuous and eventually catastrophic damage. It is therefore highly recommended that routine leak checking and repair be a part of any good preventative furnace maintenance program.
An Excerpt: “Why is helium used to detect leaks? Helium is used as a tracer gas to detect leaks for several reasons. These include the fact that it constitutes only ~ 5 ppm in air so that background levels are very low. Helium has also relatively low mass so that it is ‘mobile’ and is completely inert/non-reactive. Helium is also non-flammable and generally widely available and low cost. This association with helium is one of the reasons why one of the most accurate and rapid leak detection methods employs helium as the tracer gas and a mass spectrometer for the analyzing/measuring. Furthermore, helium is chosen as a tracer gas because it is light, very quick, and absolutely harmless.” >> Continue Reading
See lessWhat is a gas ballast valve on a vacuum pump?
The gas ballast valve on a mechanical oil-sealed rotary vacuum pump is a very simple device that offers several potential benefits for vacuum pump users and when used correctly can keep a vacuum pump working well. However, gas ballast valves but are often overlooked and are poorly understood, this aRead more
The gas ballast valve on a mechanical oil-sealed rotary vacuum pump is a very simple device that offers several potential benefits for vacuum pump users and when used correctly can keep a vacuum pump working well. However, gas ballast valves but are often overlooked and are poorly understood, this article helps take some of the guesswork out.
An excerpt: “When pumping atmospheric air (or gas) in a vacuum system, however “pure” it may appear to be, it will invariably contain some vapor. During the compression process in the pump, this vapour will condense. Failure to remove it will form a contaminant which will prevent the pump from achieving its optimum vacuum pressure. Also, the condensate can enter the pump’s mechanism, for example the oil in oil-sealed rotary pumps, where, as a contaminant, it can have a detrimental effect.” >> Continue Reading
See lessWhat type of water treatment do you recommend for a closed-loop cooling system?
Every closed-loop cooling system needs a modest amount of chemical treatment. Most are used once and then checked yearly. We recommend a sodium nitrite-based inhibitor with biocide to prevent biological contamination. This treatment is usually done at a 1% concentration so not much is needed. TheseRead more
Every closed-loop cooling system needs a modest amount of chemical treatment. Most are used once and then checked yearly. We recommend a sodium nitrite-based inhibitor with biocide to prevent biological contamination. This treatment is usually done at a 1% concentration so not much is needed. These inhibitors will protect both the ferrous and non-ferrous materials in your piping system. Many treatment chemicals come with a colorant which allows the treatment to be visually monitored.
Source: Dry Coolers
See lessWhat is the difference between ethylene glycol and propylene glycol?
ETHYLENE GLYCOL (EG)Is the green liquid we used to have in our car radiators. It’s the least expensive, hurts heat transfer the least, and hurts pump performance the least. It is toxic so its falling out of general usage. It is very corrosive so a suitable inhibitor package must be used to protect yRead more
ETHYLENE GLYCOL (EG)
Is the green liquid we used to have in our car radiators. It’s the least expensive, hurts heat transfer the least, and hurts pump performance the least. It is toxic so its falling out of general usage. It is very corrosive so a suitable inhibitor package must be used to protect your piping and equipment. Never use ethylene glycol for corrosion protection! Its only use is to prevent slushing and freezing of your coolant.
PROPYLENE GLYCOL (PG)
It’s the pink liquid we currently have in our car radiators. It’s about 20% higher in cost than EG, hurts heat transfer due to its high viscosity, hurts pump performance due to its high viscosity, and is needed in slightly higher concentrations than EG for equal freezing protection. Its winning appeal is its low toxicity. It is corrosive so a suitable inhibitor package must be used to protect your piping and equipment. Never use propylene glycol for corrosion protection! Its only use is to prevent slushing and freezing of your coolant.
DO NOT USE AUTOMOTIVE ANTI-FREEZE. Coolants for automobiles have inhibitors based on aluminum. Their inhibitor package is wrong for our industrial cooling systems.
Source: Dry Coolers
See lessWhat is the difference between freeze protection and burst protection in a water cooling system?
Freeze Protection requires a glycol concentration level sufficient to prevent the formation of ice crystals at the lowest temperature experienced by the fluid. Freeze protection is imperative when the system requires pumping. Slush is formed when you get colder than its freeze protection rating. BurRead more
Freeze Protection requires a glycol concentration level sufficient to prevent the formation of ice crystals at the lowest temperature experienced by the fluid. Freeze protection is imperative when the system requires pumping. Slush is formed when you get colder than its freeze protection rating.
Burst Protection only requires a glycol concentration high enough (generally 30% by volume or more) to prevent bursting and other mechanical damage from freezing, but not necessarily high enough to keep the fluid pumpable. Burst protection requires less glycol than freeze protection and is suitable for chilled water systems that are dormant in the winter. As the temperature drops below the freezing point of the fluid in a system with burst protection, ice crystals begin to form, and the solution becomes a slush. The fluid expands as ice is formed. This mixture may or may not be pumpable, but it is fluid enough so that the excess volume flows into an expansion tank without damage to the system. As the temperature drops further and all the water freezes, the glycol will begin to freeze and contract.
Source: Dry Coolers
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