The industrial community has always been on the search for more effective solutions to the problems caused by metal-on-metal contact. Since this type of contact occurs through all stages of the manufacturing process, including the operation of equipment, and both assembly and disassembly procedures, the list of potential issues is long. The answer is anti-seize compounds — now used to prevent galling, seizing, corrosion, heat freezing, cold welding and the stripping of fittings and bolts.
All the above problems can be accelerated by, or related to, both environmental and chemical corrosion, torque, high temperatures, friction and load. Lubricants have long been used as shields or barriers to decrease the likelihood of metal surface deterioration occurring. Although traditional greases and oils are acceptable for some applications, many do not last when the temperature rises above 400° - 500°.
Why use anti-seize compounds?
The development of an anti seize compound provided fresh solutions to an old problem. Various applications can now properly lubricate their metals at far higher temperatures.
The way they work is quite simple. For low temperatures, they contain the needed greases and oils, but they also contain solids that are contained within the formulation for high-temperature use.
Habitually, these anti-seize compounds are brushed onto various components to eliminate the corrosion, which inevitably will see fasteners seize over time. This seizing makes equipment part removal time consuming and difficult, resulting in the potential need to drill out fasteners or cut the head off.
Along with increased service costs, key equipment being offline will either slow production down, or bring it to a grinding halt. By using solid or metal content with low friction coefficients, the compounds continue to work after the lubricant has dissipated.
The importance of solids
Once the temperature range for grease and oil dissipation has been reached, the solid portion of the compound takes over on flanges, threads, bolts, etc., and "plates" the metal to resist a variety of detrimental conditions such as corrosion, rust and friction.
Not only is the solid portion of the compound important when high temperatures above 500° are reached, but the solids also enhance the lubricating performance at lower temperatures. Common additive materials like aluminum, graphite and copper far outperform standard greases when higher load bearing pressures are required.
Anti-seize compounds also ensure ease of assembly and disassembly. The type and percentage of the solid in the formula will determine temperature limits and protection degree.
For example, aluminum has a melting point of approximately 1,220° F. This would mean an aluminum anti seize compound would have decreased effectiveness above this temperature, and using a product with a solid that has a higher melting point, such as nickel (roughly 2,600° F), may be indicated.
Benefits and applications for an anti-seize lubricant
In addition to providing protection against corrosion, seizing and rust, the use of an anti seize lubricant also provides constant tension and torque, reduces friction and retards galvanic action between unrelated metals.
Some of the applications where anti-seize lubricants provide the greatest benefit include unions and tubing, studs and bolts, valves and pumps, valve stems and gland plates, joints and couplings, dies and punches, plugs and nuts, drives and shafts, and bearings that are slow moving or heavily loaded.
How to choose the correct compound
Different anti-seize compounds are better suited to certain applications than others. Several factors influence the final decision, such as the type of environment the compound will be used in, whether there are any temperature requirements and what the application is if there will be an issue with carbon resin. Also, you must take into consideration if the compound may meet any chemicals, alkalis or acids that could affect its effectiveness.
Offshore and marine use
When using an anti-seize compound in wet environments, it is imperative you choose a marine grade anti seize compound with molybdenum disulfide that is specially formulated for the unique requirements of marine use. The advanced formulation of non-metallic anti-friction material prevents damage to bolts and nuts, prevents interference of sliding components, fills imperfections and voids, and bonds easily to any metal surface.
Common usages for an anti-seize marine compound include engine assembly bolt lubrication, sliding door track lubrication, heat exchanger bolts and boiler covers.
Chemical resistance: Where there is the need for an anti-seize lubricant capable of resisting chemical interference and depending on the application, you want to look for products such as flexible gasket makers, marine or food grade compounds, and anti-seize compounds that contain copper, nickel or aluminum with graphite particles.
Heat resistance: For high-temperature applications, rigid flange sealant gasket makers, anti-seize compounds composed of nickel, copper and aluminum, are the preferred choices. Additionally, both food and marine grade compounds resist heat well.
Cold and weather resistance: When extreme weather temperatures and conditions drop the mercury, for anti-seize products to work effectively, they must be able to resist cold. Both marine grade and nickel compounds are good choices.
Depending on the use, it may be essential to choose an anti-seize lubricant that has either a medium or slow set time. The flexibility needs of your application may also be a consideration. Anti-seize compounds are available in rigid or flexible, ensuring your requirements are always met.
Ultimately, the anti-seize lubricant you choose will primarily depend upon the factors listed above. Since most are general purpose, you can potentially use the same compound on a variety of surfaces throughout your processes.
Regardless of the compound you decide to work with, you can rest assured you are choosing from a line of superior products that will continue to facilitate operations for many years to come.