Neolube’s Anti-Galling Performance Is Proven in Over 48 Years of Successful US Navy Nuclear Power Plant Operations

Client

The US Navy Nuclear Propulsion Program has been designing, building, and operating nuclear reactors for Navy use since the USS Nautilus (SSN 571) was authorized by Congress in 1951 and commissioned in 1954. The program has a superb safety record of steaming over 157 million miles on nuclear power. There are currently 96 reactors operating. The total reactor-years of safe operation is now over 6,700 years.

Challenge

In the early days of the program, galling was causing primary coolant valve caps to get stuck and require cutting to remove. Damage to the valves themselves resulted in possible valve replacement costing thousands of dollars and keeping the strategically vital submarines offline. That was an unacceptable situation.

Neolube was always one of those “hidden secrets” that made our nuclear power program so successful. It was not as high-tech as new fuel plate designs or modern electronic control systems, but it did its job day in and day out for us. If our technicians took 1 minute or less to put on a coat of Neolube, we had 100% confidence valve caps would come off when we needed them whether in an emergency or for routine maintenance. 

Capt. Hubert Hopkins

Commanding Officer USS Sand Lance (SSN660), United States Navy

Solution

Neolube #1 was developed to be dry with extremely high purity and consistency. It is fully tested to verify every batch has no potentially harmful halogens like chlorine or other halogens. These halogens are extremely reactive and in the presence of stainless steel can cause problems like crevice corrosion. In any environment with stainless steel piping systems under high temperatures and pressures, halogens must be avoided. Neolube provided a great solution to the potential contamination, but only if stringent testing was conducted and documented. 

Neolube #1 now conforms to the stringent Military Spec MIL-L-24131C. In addition to specifying strict limits for lubrication performance, the MilSpec also limits the amount of Ash, Florine, Chlorine, Lead, and Sulfur. Mercury, Lead, and Boron must also be eliminated from all parts of the product processing and testing.

The purity of the Neolube #1 product ensures that it does not contribute towards damage to stainless steel piping systems or provide any source contaminant that may become radioactive itself when exposed to high levels of radiation. 

As a “dry” lubricant, Neolube #1 is easy to apply (and remove) and consistent results can be obtained with minimal training and in a wide range of amounts applied. It’s simple and reliable with only the graphite lubricant remaining within seconds of application. There is no need to clean the old lubricant off the threads, saving time and ensuring long term success without strict application procedures.

Image: Technical drawing of USS Nautilus (SS-168) and USS Nautilus (SSN-571). Original Source

Results

Neolube is still in use by the US Navy and has been for over 48 years since 1974. It is in use in hundreds of commercial power plants around the world and is expanding into more traditional industrial companies and process plants. 

Although galling can still occur with valve caps or other parts lubricated with Neolube #1, this is always the result of operator error either by assembling the threaded joints incorrectly or forgetting to apply the Neolube. This is a rare occurrence in today’s nuclear power plant operation, thanks to Neolube #1.

Downloads

Neolube No. 1 Technical Data Sheet

Neolube No. 1 Safety Data Sheet

The post Neolube’s Anti-Galling Performance Is Proven in Over 48 Years of Successful US Navy Nuclear Power Plant Operations appeared first on NEOLUBE® Industrial Dry Lubricants.

Galling is damage that occurs on sliding metal surfaces when a combination of excessive force and high friction cause the transfer of material.

Often macroscopic, between the two surfaces the metal from one surface tears away and becomes embedded in the other surface. The most common galling example is thread stripping in bolts, nuts, and other parts and is most susceptible to aluminum, stainless steel, or other very hardened steel and alloys. 

Why is Galling a Cause for Concern?

Galling is a sudden failure event and can cause all kinds of complicated repairs to machinery. The galling result can be as severe as friction welding of the two parts together so they can’t slide further. In threaded connections, this means stuck bolts.

Galling is common in many industrial applications such as sheet metal fabrication, engine bearings, pistons, air motors, and etc. Preventing galling in industrial settings can significantly reduce major unexpected outages and save vast amounts of money in lost production time. 

How to Prevent Galling?

Galling is a function of three things, one must address each specific application where prevention is needed. 

1. Lubrication is a crucial ingredient to galling prevention. Any sliding surfaces in an environment with high forces possible and using susceptible materials mandate proper lubrication. Dry graphite-based lubricants, such as Neolube, are custom made for those applications where a simple wipe-on, no-mess, no-contamination lubricant is needed. In some other less demanding cases, a little oil or grease will work. In food processing applications, special lubricants must be used that are food grade. 
2. Reducing force is the second key to preventing galling in existing systems. For threaded connections, for example, the second any tension is felt in the movement of the two parts, the force must be removed. Reversing the direction of a threaded bolt and moving it back and forth can free up areas that are starting to gall. This doesn’t work inside pistons or sliding machinery where only lubrication is the solution once the design is set. 
3. Material selection in the design phase is also critical. Softer steels and other metals are much less susceptible to galling and should be used in sliding applications where possible. Corrosion, hardness, strength, and many other design considerations dictate when soft metals won’t work. Metal surface treating and coatings can be effective at mitigating the risk of galling as well. 

Neolube #1 and Neolube #2 are great lubricants for reducing the probability of galling, particularly in stainless steel and other hardened alloys. The graphite layer that is dry and left on the sliding parts can retain its protective lubrication thickness in the contact zone where galling can occur. The ability to tightly control surface contamination with outside agents, like halogens, is the other significant benefit to a product like Neolube, which was developed for the Nuclear Power Industry but is also effective for thousands of different industrial applications. 

Contact Huron for all your complex lubrication and thread sealing applications. Call 810-984-4213 today. 

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