A cotton ball soaked in Vaseline will burn a very long time, and actually makes a good fire starter. Since connectors are often near insulation or other things that can act like wicks, petroleum jelly is not the best thing. This is especially true since grease migrates in warm temperatures. Internet forums thrive on myths. Forums often claim dielectric grease thermally insulates connections.
Forums also claim dielectric grease electrically insulates connections, such as in connectors and on battery posts. Neither is true. Here is a test using a watt dissipation resistor.
The resistor is mounted to the heatsink with a stack of Belleville washers. These washers are conical spring washers. They maintain a constant pressure when partially collapsed.
Proper Belleville washer implementation ensures compression or pressure against the heatsink is essentially the same between tests. The Belleville eliminats cap screw torque as a factor in results. Best result is at bottom. Using too much dense grease, like thick heatsink compound, greatly increased thermal resistance. This occurred because compression pressure was not enough to force excess grease out of the area between the heatsink and the resistor tab.
When the layer was thinned to a light "wipe" of grease, thermal resistance fell off significantly. There is essentially no difference between Permatex Dielectric Tune Up Grease and a special heatsink compound used on high-power transistors.
Flooding a connector is not acceptable at high power, because most greases will carburize when subjected to an arc. Greases also change the dielectric constant, lowering the dielectric constant in the connector. This may create an impedance bump at very high frequencies, the problem's effect on the system being entirely dependent on the length of the bump in electrical degrees and the amount of the bump.
Not all things that show on a TDR meaningfuly alter performance, but they do indicate a potential problem. In regular low voltage multiple-pin circuit connectors, such as automotive applications , flooding with a proper insulating grease of low-viscosity dielectric grease is perfectly acceptable unless a manufacturer recommends against it. The grease should have good stability and not contain metals in any form, and be specifically designed for use as a dielectric grease.
This generally is a silicone dielectric grease, although some Teflon based greases are acceptable. In single low-voltage terminals or connections, such as metal-to-metal joints, grounds, or battery posts , almost any pure grease of light viscosity will be acceptable. Caution should be used with greases containing metallic powders to be sure any metal is compatible with the embedded grease metal. Connection enhancement from embedded metal powder is very minor, if it exists at all, and unless you match the grease to the connector material, risk of interaction with base metals might increase.
In single high voltage connections, such as spark plug boots or other high voltage connectors x-ray, neon sign, or HV power lines , only pure dielectric silicone greases should be used. Generally a light coating or wipe is all that is required.
Dielectric grease will actually increase voltage breakdown across insulators, especially in the presence of moisture. Never use or allow a metalized grease around HV connections.
The important physical characteristic is that any grease must have low enough viscosity to push out of the way at contact points, be water or liquid resistant, and be stable enough to remain in place as a protectant against moisture and air for a long time. It will not do any good to apply a grease that does not do required functions of excluding air and moisture, and lubricating the interface to prevent galling or fretting , for extended periods of time.
Contrary toInternet rumors, advertisements, and articles low viscosity silicone dielectric grease will NOT insulate pressure connections. Because it is so robust and features low friction properties, it is often used as a solid lubricant. Sliding surfaces, such as axles, require different types of grease and black moly grease is used whenever the services in question are under great pressure.
In most cases, you will use whatever type of grease is called for in the service manual. For anything that requires grease, there will be a symbol that resembles a grease gun and has one of the following:. The different types of greases are not interchangeable. For instance, using general-purpose grease on a drive spline can end up in disaster, due to the pressures involved. On the other hand, moly grease would not work well on an axle due to the fact that it is very slick.
Several different molecules make up the hexagonal crystal platelets of moly. There is one molybdenum atom and two sulfur atoms in each molecule of moly. When choosing a grease gun, there are several things you should consider, including how much grease will be applied and what type of machinery will be lubricated.
The most popular grease guns are the manually operated, pneumatic and battery-powered styles. John Deere grease fittings are manufactured to the most stringent quality standards and are heat-treated to SAE specifications. It goes without saying that it is imperative to check with the local authority before purchasing or getting down with the sizing process of grease traps. If the trapped FOG is not pumped out when needed, it becomes thick and may begin to escape via the outlet tee.
This could consequently lead to your commercial kitchen and business being shut down by local sanitary officials for wastewater plumbing system damage. Dishes should be scraped before being washed. As a result, less food and grease FOG will make its way down the drain. Again, as a standard practice, high-fat liquids and fryer oils should never be allowed to flow down the drains, even with water, or else the need for grease recovery increases.
The more grease in the waste, the more often it needs to be pumped. Waste in the form of frostings, sauces, meats, salad dressing, and butter oils means a higher frequency. Busy establishments lead to more waste products being washed down the drains.
For this reason, busy seasons mean a higher pump frequency. If the grease interceptor is not drained often enough, the inlet and outlet often become clogged with fats, oils and grease FOG. For this reason, the drainage should be cleaned at a higher frequency. Furthermore, other drains in your establishment also require some maintenance in terms of periodical cleaning.
For best practice, have the sewer lines cleaned at least once a year, and more often if the need arises. To mitigate issues associated with foul odors from blocked drains and sewer system issues, officials from the local health and hygiene department recommend the following tips:.
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