Green and gold in lubrication

Environmentally friendly fluids and sealing systems offer a new perspective.

By Joe Woods, Trelleborg Sealing Solutions June 9, 2015

The development of biodegradable engine oils, hydraulic fluids, and other lubricants provides a safer alternative to traditional fuels, especially in environmentally-sensitive areas and environments.

For example, in order to mitigate the costs associated with petroleum spills, many offshore operators are using or considering environmentally safer products. These types of fluids can protect the users against cleanup costs, downtime and potential fines.

While replacing all traditional hydraulic fluids with bio-fluids is not possible, there is an increase in the use of such fluids. Care must be given in selecting the right product for a specific application and to ensure that those products can meet the same performance standard as traditional fluids.

Equipment operators may prefer biodegradable hydraulic fluids, and fluid manufacturers are meeting these demands as they add new fluids and formulations based on low toxicity. While this is important, it is also crucial that the hydraulic component and system manufacturers are able to ensure that the products they provide are useful and compatible with fluids and account for the end user’s requirements.

Education for system designers combined with the cooperation between seal and fluid manufacturers is really crucial to successfully navigate such a complicated web of chemistry interactions.

Complex formulas

Hydraulic fluids and seal materials are similar in that both are extremely complex and variable in regards to their formulation. You will never hear a manufacturer of either say that their formulation is identical to another supplier, and it should never be taken for granted by the equipment supplier that they are.

Inside the very familiar group of materials called NBR (nitrile butadiene rubber) are thousands of different formulations that have been compounded differently for a multitude of reasons. Those reasons can relate to desired material capabilities such as temperature or chemical resistance, they might be related to manufacturing concerns such as mold flow and cure time, and they are most certainly affected by cost.

To pick up any 70 Shore A NBR from one company and assume it will function the same as the 70 Shore A NBR from another company is a mistake that can lead to serious consequences in your application. The same holds true for hydraulic fluids.

Environmentally-friendly hydraulic fluids, as with all hydraulic fluids, have considerable variation in their formulations not only in the selection and blending of the base stocks but also in the variety of additives that can be chosen to get the necessary properties.

The dozen or so additives are considered proprietary and for the most part are going to be kept secret as long as required regulatory tests are passed and performance requirements are met.

Collaboration is key

Customers who turn to their suppliers with an application in which they require a biodegradable fluid find that it is usually because the end customer has specified the fluid. It is in this scenario that suppliers need to collaborate with their customers in trying to determine seal material depending on the fluid type. In addition to working with the customer, suppliers should also be working with fluid manufacturers to develop a mutual understanding of how seals behave in their fluids and vice versa. This proactive approach solves challenges on both ends of the supply chain.

It is very important that hydraulic fluid transfer power efficiently and economically. Fluids with poor lubricity characteristics can usually be utilized if the appropriate seal material selections are made. Excessive heat build-up due to poor lubrication will result in seal wear and hardware damage otherwise.

Lubricant systems within marine environment

As demands on lubricant systems increase, the likelihood of accidental release of fluids increases. Increased operating temperatures, pressures and working cycles shorten the life of circuit components. The single best approach to protecting the environment, the equipment and the operation is to deploy the best sealing solution tailored specifically for the application in order to prevent leaks and spills.

Routine maintenance is also key. A good preventative maintenance program will increase productivity since equipment is utilized more. It will keep down costs by allowing more in-shop maintenance since there will be less emergency work. Additionally it will decrease equipment downtime, reduce safety hazards, increase equipment life, and minimize fines and cleanup costs.

Oil and gas exploration and production

One of the biggest applications for biodegradable fluids is in oil and gas exploration and production. Fluid suppliers have responded by introducing new, eco-friendly biodegradable and non-toxic fluids based on a variety of different chemistries. What is needed is not only a sealing solution that can handle the fluid, but also all the other demanding parts of that application, such as salt water, storms, various tidal and freezing conditions.

In critical operations, these systems need to be in continuous operation. Any downtime is very costly. Seal manufacturers have responded to this trend by ensuring their seals are able to interact appropriately with these new greener fluids, which many times do not have the best lubricating properties.

Oil and gas exploration applications continue to be complicated due to economic pressures that are moving the industry toward higher operating pressures, temperatures, and working cycles—all of which are more efficient but also increase the stress on components such as seals and lubricants.

Additionally, government regulations aimed at protecting the environment must be considered for those who design, build, or use hydraulic systems. With this in mind, it is important to understand the entire sealing system, gather all customer requirements, and evaluate the application. Specifically, a shoulder-to-shoulder design engineering approach where collaboration between the seal supplier and the customer’s application engineers makes a difference in delivering substantial added-value and a total value of ownership advantage.

Going green with better sealing systems

There are a number of advantages to using biodegradable hydraulic fluid, but the most important factor is that it can prevent pollutants from contaminating the soil and ground water.

Seal suppliers and hydraulic equipment manufacturers must be knowledgeable of chemical compatibility requirements and test methods. Working with material suppliers that understand these challenges and that are able to perform the proper testing to ensure compatibility is imperative for a smooth transition.

In addition to compatibility, suppliers should also know how to extend advantages received with standard hydrocarbon-based fluids such as a longer operating life of the seal, lower friction and reduced energy consumption, enhanced sealing techniques and the delivery of a total value of ownership.

Joe Woods is fluid power segment manager for Trelleborg Sealing Solutions. (