It can be tempting to devote all of your attention to the material that is flowing through the valves in your process control system, but it’s just as important to invest some time and effort in maintaining the materials within your valves. Seals, gears, and other internal components need to be cared for with routine maintenance, but there is probably no valve maintenance activity as important as proper lubrication.
Grease performs several crucial tasks that make valves work better and last longer. In order to get the most out of your valves, it’s essential to choose a grease that will deliver superior performance. You might be thinking that a penny saved is a penny earned. But if you’re pinching pennies in the area of valve maintenance, you’re being penny wise and pound foolish.
Invest some time and effort to make sure that you’re caring for the valves in your process control system with the right practices and products. Do some research to identify the right grease for a given application. Adopt a no-excuses, no-exceptions attitude toward routine maintenance to make sure that the valves stay greased.
What Can Valve Maintenance Do for You?
That might seem like an odd way to phrase the question. After all, what we really want to know is what proper maintenance can do for your valves right? But, when you invest the time it takes to research and organize a routine maintenance program and the effort that it takes to make sure it gets executed, you’ll be doing yourself and your valves a big favor.
Proper lubrication means never being in a situation where you’re counting on a valve to perform only to have it let you down. Proper maintenance means never having to explain why your valve repair budget for the quarter is double, triple, or even quadruple what it was last quarter. In short, taking care of your valves is taking care of your bottom line.
One of the most important benefits of properly lubricate valves is reduced wear and tear on moving internal parts. The mechanical joints that join stems, bushings, and gears benefit from regular lubrication with quality grease. In fact, some metal-to-metal contact inside of valves can’t work at all without lubrication. Plug valves need to have the hydraulically activated surface coating of extreme pressure grease in order to form a seal.
Plug valves require lubrication to form a seal but grease can offer supplemental emergency sealing power in a variety of valve types. Properly lubricated valves are protected from the harms of corrosion and oxidation.
Choosing the Right Grease for Your Operation
The organization that sets the standards for lubricating grease is the National Lubricating Grease Institute (NLGI). They have developed a scale to measure the viscosity of grease. It runs from 000 (least viscous) to 6 (thickest). When using grease to lubricate process control valves, medium viscosity in the range of 1-2 is typically the best.
In addition to knowing the viscosity that will work best for your operation, it can be important to consider the components that make up the product’s base and soap. The base of grease can be derived from petroleum, animal, or plant materials. The soap, or thickener, can comprise a variety of thickening agents to give a grease its unique characteristics.
When you shop for grease, you will likely find a two-letter prefix in the description. “AP” denotes an all-purpose grease that has good thermal and structural stability. Greases of this type are often used on cars and trucks but can be used for light-duty valve applications. “MP” means that you have a multi-purpose grease. MPs are #2 NLGI greases that are appropriate for light industrial and agricultural applications.
For most process control applications, you will want an “EP” or extreme pressure grease. It is the most robust of the three classifications. EP grease contains special additives. These prevent it from becoming compressed during high-pressure exposures or shock loading. EP grease will also carry solids that bond with the surface of the metals it comes into contact with. This sub-layer will prevent metal-to-metal contact even when the grease has been washed out.
Since process control is a vital part of so many industrial operations, it is impossible to list all of the special circumstances that require additional consideration when selecting the right grease for your valve maintenance program. For example, both chlorine and oxygen services will require you to use grease made of certain synthetic compounds. In high-temperature applications, you will need a grease that carries graphite or lithium.
In the oil and gas industry, pipeline and gathering line valves fall under the supervision of the American Petroleum Institute (API). Under API specifications, gate valves have to be equipped with an injection port. This allows you to pump grease into the valve to seal leaks. The API also publishes specific standards for the lubricants used in plug valves that come under their oversight.
Valve Magazine offers a fitting final word on this subject. “Valve lubrication is vital today for effective and efficient valve operation . . . Today’s valve lubrication needs require specific compounds designed to meet the broad range of different valve applications. That means the squirt-can should remain on the shelf” (source).
Call PSA, Inc. to speak to one of our valve maintenance experts. We’ll be happy to help you track down the perfect grease for your routine maintenance plan.
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