Using the correct oil sampling hardware helps ensure you’re getting an accurate sample every time. Below we’ll talk about the oil sampling equipment you need to take a precise oil sample.
Importance of Proper Oil Sampling
A lubrication professional extracting a representative oil sample is only as good as their instruments, even if they know how to get a suitable oil sample. Without these two things, you’ll likely wind up with a non-representative oil sample, which can have detrimental consequences. Using the wrong or inadequate oil sampling hardware, taking oil samples from unsuitable locations, and even mishandling the samples can all lead to an oil sample that doesn’t represent the actual condition of your equipment.
Proper oil sampling tools prevent exposing the sample or system to ambient air. The right equipment allows oil sampling without opening the bottle. Having a correct-sized and cleaned bottle, a zip-lock sandwich bag, the correct sampling port and valve, and a sampling device like a vacuum pump are all things you’ll need to do this.
Below we’ll discuss the various oil sampling equipment you’ll need to take a representative sample of the oil inside your machinery.
Requirements
Accessories
- Sample extraction tube
- Vacuum pumps
- Oil sample bottles
- Materials
- Opaque plastic
- Polyethylene terephthalate (PET)
- Glass
- Cleanliness
- Clean
- Superclean
- Ultraclean
- Materials
Sampling Ports
The location and method of collecting oil samples are two of the most critical aspects of the sampling process. But ports are only sometimes where you need them to be.
After detecting unusual conditions, installing multiple ports in strategic locations helps isolate components and diagnose problems. Primary sample ports should be located at routine sampling points to ensure the most accurate evaluation of fluid and machine condition. They track oil pollution, wear debris, and the chemical and physical characteristics of the oil. Primary sampling port locations vary, but circulating systems should be located on the return line before the fluid enters the sump or reservoir.
Secondary sampling ports can be installed on a system to isolate specific components. By inspecting individual parts, you can pinpoint the source of the contamination. When the primary port sample identifies an unusual reading, and you need to study the root cause further, take an oil sample from the secondary port location.
Under normal operating conditions, a proper sample port draws fluid from the most representative parts of the equipment using gauge adapters, port adapters, and sample ports with pilot tubes.
Sometimes a machine’s design or operation environment necessitates installing a remote oil sampling port through line extensions. It may be necessary to take samples for condition monitoring during runtime conditions. Many machines can’t be accessed during normal operating conditions, but yet they may be the most important to sample.
Sample Valves
Sample valves are put at ports on sumps and oil circulating lines for clean and efficient oil sampling. This achieves a controlled, fixed sampling location. Sample valves can aid in the prevention of leaks and unintentional sample contamination. They also don’t interfere with the machine’s regular operation. This allows samples to be taken during normal operation, improving their quality.
Depending on your system, you might need to use many pieces of oil sampling hardware with the appropriate valve. Consider the following valve options:
- Portable high-pressure valves
- Minimess valves
- Ball valves
- Stauff sampling valve
- Circle-seat control valve
- Fluid line sampling valve
- Parker aerospace sampling valve
- Taylor sampling valve
- Eaton sampling valve
- Checkfluid sampling valves
- Caterpillar sampling valve
Improvements
Over the years, technology and ingenuity have improved upon the designs and availability of oil sampling hardware to make sampling more accessible and more representative of system and fluid conditions. Two of the most notable oil sampling equipment recently introduced are the Ultra Clean Vacuum Device (UCVD) and Luneta’s Condition Monitoring Pod (CMP).
The UCVD is a high-tech sample bottle with a pre-set vacuum that keeps it ultraclean and free from moisture and impurities. Its nozzle attaches to a sample tube, which connects to the sampling valve. Turning the nozzle releases the vacuum, drawing oil into the bottle. This method works with any lubricating system, including pressurized systems, without needing a standard hand-pump vacuum.
The Condition Monitoring Pod is a multifaceted piece of equipment that lets an inspector perform many tasks from the same port. The CMP, also known as a “multi-parameter inspection pod,” combines an oil sight glass and a sample port into a single piece of equipment. The CMP lets you view oil levels, color, clarity, aerating and foaming, corrosion, varnish, and wear debris. Oil is drawn through the built-in, vacuum-compatible port, with the CMP’s stainless-steel pilot tube bending to reach the optimal position inside the machine.
Oil Sampling Methods
Pressurized Line
Sampling a pressurized line on an engine equals sampling a pressurized line on any industrial forced lube system. The lubricant is drawn from the sump, filtered, and pumped to the required lubrication points. The goal is to install sampling hardware in the live zone at a turbulent point past the pump and before the filter.
When sampling is needed, the hardware collects a representative, repeatable sample while the system runs. Using sampling equipment maintains a closed system, letting you retrieve the sample without exposing it to outside contaminants.
Drop Tube
Drop-tube vacuum sampling is a straightforward, low-cost method of obtaining oil analysis samples. This method requires a large fluid flushing volume, needs help getting consistent samples from the exact location, and needs help sampling high-viscosity fluids.
The location will always be in the same general vicinity when using this method in conjunction with a dipstick tube. The existing variable is the depth at which the tube is inserted into the volume of oil in the sump.
To solve the issue of tube depth, insert a premeasured or graded sample tube to a known depth, which will limit the tube’s termination point to a suitable area of changeable location.
Drain Port Engine Oil Sampling
To collect a representative oil sample from the sump, first purge a large volume of oil. Then, catch the sample midstream, ensuring that the oil entering the bottle reflects the system’s overall condition. By doing so, the sample avoids settled contaminants. Finally, the collected oil can be analyzed confidently as representative of the system.
This method yields cleaner midstream samples, but you must carefully interpret data from a drain port. It is typically applied when replacing the oil with new fluid. Under typical operating conditions, this does not apply to trending the in-service oil
Every engine oil sampling procedure has various methods and associated variables. To be successful, it is necessary to understand the limitations and variability of each system and assume the appropriate amount of accuracy with each.
Implementing a World-Class Lubrication Program
CRE Philippines manages every lubrication process from purchasing to determining re-grease volumes for each plant bearing through our program designed in partnership with Noria.
Furthermore, implementing lubrication programs to diagnose incipient machine failure through oil analysis entails cost. As such, thorough planning must ensure that your resources are well-spent.
You will be confident to start your Machine Diagnostics Program and Lubrication Program with our full support every step of the way.
Sources:
Noria Corporation. (n.d.). 3 Engine Oil Sampling Methods. MachineryLubrication.
https://www.machinerylubrication.com/oil-sampling-hardware-31620