A lube oil system accumulator (LOSA) is a component in a lubrication system that stores lubricant. The LOSA collects and releases lubricant as necessary to keep the oil level consistent in the system. Without an accumulator, the oil level would constantly fluctuate, which could cause damage to the machine. Read on for more about what a LOSA is, how it works, and some of its benefits. By understanding the functions of a lube oil system accumulator, you can ensure that your equipment remains in good condition and operates at peak efficiency.
What is a Lube Oil System Accumulator?
A lube oil system accumulator is a type of pressure vessel used to store oil along with a mechanical mechanism for maintaining pressure if the pump fails. The combination of the two components reduces the impact of changes in oil pressure. LOSA’s can use a few different types of mechanisms to maintain pressure, such as a spring, gravity, or gas-loaded accumulator.
While maintaining oil level and pressure is the primary function of a lube oil system accumulator, it isn’t the only function. Another application is for the storage of fluids for disposal. Lubricants at the end of their useful life can transfer to the tank, then you can pump them out when the tank is full. For instance, this type of accumulator is often utilized in sub-sea oil drilling. Once the accumulator is full of waste fluids, they can be safely pumped to the ocean’s surface for disposal.
Why are Lube Oil System Accumulators Important?
Loss of lubricant flow is one of the major factors contributing to lube oil system failure. This can result in severe bearing wear and early replacement. Lube oil system accumulators serve as a preventive measure against these failures. When needed, they provide a temporary supply of lubricant preventing a pressure decrease. This is especially useful during an electrical outage, a switchover between oil pumps, or during brief shifts in demand. Additionally, under these circumstances, lube oil system accumulators perform effectively in preventing bearing damage and extending bearing life by providing oil to the bearings.
How Many Lube Oil System Accumulators Do You Need?
The crucial detail when adding a LOSA to your lubrication system is to make sure you have the right amount for your needs. For example, a lube oil system that feeds 400 to 500 gallons per minute requires the storage of at least 100 gallons of lubricant under high pressure. A system of that size would likely have 8 to 10 accumulators connected in series.
The Different Types of Lube Oil System Accumulators
Spring Accumulators
This type of lube oil system accumulator has a spring-loaded position in a cylinder. The spring pressure matches the hydraulic pressure because the oil fills the cylinder, compressing the spring. Then, if the oil pressure drops, the spring pushes the oil back into the system. Because the spring wears out and loses its flexibility, you should only use this type of accumulator in low-cycle applications. They also struggle to keep the pressure steady.
Gravity-Loaded Accumulators
Weights are used in gravity-loaded accumulators to drive a piston and generate the required pressure. These accumulators can provide nearly constant pressure, but they are larger, heavier, and more expensive than other varieties.
Gas-Loaded Accumulators
Finally, gas-loaded accumulators use compressed gas to create the required pressure. There are two options within the gas-loaded accumulator category: separator and non-separator accumulators. As the name implies, there is no barrier separating the gas from the liquid in non-separator accumulators. Despite having the most oil storage capacity and being the simplest design, non-separator accumulators have the drawback that the fluid may absorb gas at high pressures since there is no barrier separating gas from oil. The absorbed gas creates bubbles in the oil when the pressure decreases, which may result in foaming in the oil and damage to numerous system components.
Alternatively, separator accumulators have a barrier between the gas and the fluid, like a pressurized rubber bladder. These accumulators are composed of 300 series stainless steel in compliance with API specifications and can handle pressures as high as 1,500 psi. The bladder’s quick response time and great flexibility enable the accumulator to swiftly make up for pressure decreases in the system, protecting the bearings and other parts from harm.
The Bottom Line on Lube Oil System Accumulators
Lube oil system accumulators are important components of many lube oil systems. There are three main types of accumulators: spring-loaded, gravity-loaded, and gas-loaded. Each type has its advantages and disadvantages. By understanding the different types of accumulators and what each one does, you can ensure your system is running smoothly and efficiently. If you have a lube oil system that is not functioning properly, don’t overlook the possibility that it may be due to a problem with the accumulator. Contact a professional to help you troubleshoot the issue and get your system back up and running.
