A vacuum pump is a powerhouse machine that removes air, gases, moisture, and contaminants from a system to create a clean environment for refrigerant. These efficient and powerful machines need clean oil to perform at their peak. When oil becomes cloudy or saturated, the pump won’t work as well, and pulling a deep vacuum takes longer.

Double-duty Oil

The oil in the vacuum pump acts as both a lubricant and as a sealant. It keeps the pump vanes (rotor blades) lubricated and helps keep a proper seal for an optimal vacuum. The deep vacuum that the pump creates helps push moisture and non-condensables from the system to the pump, ensuring the system is ready for refrigerant. This process contaminates the oil in your vacuum pump, which negatively impacts the pump’s performance and efficiency by compromising its internal seal. Pumps with contaminated oil will struggle to create a strong pressure differential, leading to increased evacuation time and eventual damage to the pump.

When to Change the Oil

The need to change your oil will depend on several factors. The most effective way to maximize performance and efficiency of your vacuum pump is to change the oil after each evacuation. In humid environments systems are more likely to contain moisture. Systems with more moisture and non-condensable contaminants present will contaminate your oil faster, requiring more frequent changes to maintain performance. Moisture contamination is easy to spot because the oil looks milky or cloudy. Other contaminants can sink to the bottom of your oil reservoir, so vacuum pumps with better reservoir visibility, such as the large window on the Fieldpiece vacuum pumps, allow for more accurate monitoring.

Another key indicator that it’s time for an oil change is pump efficiency. When pulling a vacuum, if the rate at which your microns are decreasing starts to level out, this could signal the need to change oil. When pump efficiency starts to wane, pulling a deep vacuum becomes more time-consuming. Note that the time to pull a vacuum will vary depending on the size of the system, atmospheric conditions such as humidity, and the efficiency of your evacuation setup.

Oil Changes on the Fly

Some pumps on the market allow the oil in the pump to be changed while it’s pulling a vacuum, like the RunQuick® oil change system on Fieldpiece vacuum pumps. Towards the end of the evacuation is when you need fresh oil the most, so oil changes on the fly are key to working faster and smarter.

Get a Vacuum Pump that Works for You

Since clean, dry oil is crucial for faster evacuations, consider vacuum pumps that make oil changes quick and hassle-free. Fieldpiece vacuum pumps are powerful, portable and offer oil changes on the fly, saving you time on every evacuation. See the entire line of pumps, oil and other HVAC tools built and designed for techs.

For refrigerant heating and cooling systems to work correctly and optimally, the refrigerant must be free of air, nitrogen, moisture, and contaminants. Therefore, before charging a system, it’s critical to evacuate the system with a vacuum pump to create a clean and sealed environment. Here are a few tips and best practices to make your next evacuation faster and more effective. 

Tip 1: Purge with Nitrogen 

Moisture in a system can drastically increase the time it takes to pull a vacuum and removing that moisture and other contaminants is a crucial step to saving time. To ensure that the system is free of excess oxygen, refrigerant, moisture, and other contaminants, purge it with nitrogen. This is different than flowing nitrogen or conducting a nitrogen pressure test. To purge, connect a nitrogen tank and flow nitrogen through the system at around 100 PSI. This allows nitrogen to flow into one side and then out the other. The movement displaces excess oxygen and air. It also removes any dangerous gases and ensures the system is dry. While performing this purge, be sure to keep the area well-ventilated. Nitrogen can displace oxygen and create a dangerous environment for techs or other occupants, so always keep this in mind. 

Tip 2: Triple Evacuate 

When working in humid environments or on systems with significantly more moisture, a triple evacuation is a great way to remove the moisture entirely. This is an industry requirement for some OEMs, and one of the most effective techniques for systems with high moisture content. Start by sealing the system off and pulling the system down to a vacuum of between 1000 and 2000 microns. Then, break the vacuum by introducing nitrogen for 5 minutes at 5 PSIG. Perform another evacuation to 500 microns, and then break it again with nitrogen for five minutes. Perform a third evacuation and pull the system down to between 200 and 300 microns. Let the system sit for 10 minutes, or longer for larger systems. Performing the triple evacuation purges with nitrogen helps the excess moisture and other contaminants vent out of the system. Not to mention, systems with less moisture allow for pulling a vacuum faster, saving you time on the job. 

Tip 3: Change Your Oil 

Within a system is not the only place where moisture can impede evacuation efficiency. High moisture content in your vacuum pump oil considerably reduces your pump’s ability to pull a deep vacuum quickly. Cloudy oil is a sign of moisture buildup, a natural occurrence in used oil. Vacuum pumps with clean, dry oil can maintain a higher pressure differential, speeding up the vacuum process and allowing for a deeper vacuum. This means more frequent oil changes directly improve your ability to evacuate systems quickly, once again saving you time on the job. With Fieldpiece vacuum pumps featuring the RunQuick® oil change system, you can change oil in seconds without losing vacuum.  

Effective tools are only part of an effective service. Staying informed and up to date on best practice is just as important, so we hope these tips help make your system evacuations easier, faster, and better! 

Refrigerant recovery, system evacuation, and charging are the “bread and butter” processes that HVACR techs routinely tackle. Removing one of the smallest components of a system, the valve core, significantly increases the speed and efficiency of these tasks. Valve cores can block up to 90% of the flow, therefore removing it to increase the flow rate makes a valve core removal tool an important part of any HVACR tech’s toolkit.

Why Pull a Valve Core

The initial, primary purpose of a valve core removal tool (VCRT) was to replace a damaged core on a charged system without losing the refrigerant charge. By replacing the damaged valve core without having to pump down the system, you save significant time on the job.

The time saving advantages discovered in using a VCRT to replace a damaged valve core led to the best practice of removing the valve core to recover, evacuate and charge systems faster.

Removing a Valve Core on a Charged System

One of the first steps before installing a VCRT is to understand the open and close positions of the ball valve to prevent accidental refrigerant loss. When installing a VCRT on a charged system, it’s important to hand tighten the tool at the service port to prevent leaks, but not overtighten. Overtightening creates more stress on the gasket causing it to wear out faster and potentially leak.

With the VCRT installed and the integral ball valve open, slide the capture rod towards the service port valve core and slowly turn the rod tip to align on either side of the valve core. You will feel the capture tip slot into place. To firmly secure the core into the tool, slightly press the cap to ensure the core is press-fit into the capture tip. Turn the VCRT cap counterclockwise approximately five full turns to unthread the valve core and slide the capture rod back out. You can now close the ball valve, isolating the charged system, and remove the capture rod assembly with the secured valve core.

Some VCRTs, like the Fieldpiece VC1G and VC2G, have an integrated sight glass that allows you to visually confirm that the valve core has been captured before removing the capture rod from the tool. Verifying the core is captured eliminates the “Did I get it?” game saving even more time. Additionally, you can check that refrigerant is flowing through the sight glass. Once the valve core is removed, your hose can now be attached to the VCRT to begin the recovery process.

Removing the Valve Core for System Evacuation

Once you have repaired the system, performed a nitrogen pressure test and are ready to evacuate the system, you can install your micron gauge on the VCRT side port. Note that the most accurate vacuum measurement is taken at the system service port location. A VCRT with two ball valves, like the Fieldpiece VC2G, allows you to directly connect, isolate and protect your micron gauge during refrigerant recovery and charging without additional fittings. With the system at atmospheric pressure, you can now swap your recovery hose with a larger diameter vacuum hose to further speed up the evacuation process. A tip while evacuating is to open and close the VCRT ball valve to remove any trapped air in the ball valve.

Another important tip is to not insert or remove a valve core under a vacuum. This will introduce air back into the system that you just evacuated. The system should be slightly pressurized prior to inserting the core. Simply reverse the removal process to install the valve core back into the service port. Note that the best practice is to install a new valve core every time you remove one.

Removing the valve core is a common and important step for faster recovery, evacuation, and charging. Make your job even easier by picking up a Fieldpiece valve core removal tool that eliminates the guesswork and helps you work smarter.

During peak cooling season, removing a valve core on the job is as common and necessary as finding shade. Removing the core opens the valve completely, eliminating flow restrictions for faster recovery, evacuation, and charging. To simplify your job, Fieldpiece has a lineup of three ac valve core removal tools (VCRTs) that eliminates the trial-and-error process (and frustration) often faced with other tools.

Locked In
With a press-fit gasket design, the tip of the capture rod locks in the valve core the first time, every time. No adjustments necessary. With the valve core reliably secured, it won’t fall off within the tool or get lost once it’s removed. All models of Fieldpiece ac valve core removal tools have a magnetic cap on the capture rod to safely store the locked-in core on the system housing, keeping it clean and handy. PRO TIP: best practice is to always replace the removed valve core with a new one.

Seeing is Believing
Almost every technician has played the “Did I Get It?” game when removing the valve core. With no way to confirm that the core has been successfully captured before removal, you are left to remove the rod and check, releasing some refrigerant with each attempt. Also, if the core has fallen off within the tool, a quick (and dangerous) opening of the valve on a charged system can eject the core at high speed. Did we mention the frustration that sets in after multiple failed attempts to remove the core? To eliminate this annoyance, the Fieldpiece VCG1 and VCG2 feature an integrated sight glass. You can clearly see the end of the rod through the sight glass and confirm the valve core is attached before extracting it – sanity intact. The sight glass can also be used to verify that refrigerant is flowing.

Two’s Company
The VCG2 model also includes a second ball valve on the side port. This convenient addition allows you to easily isolate and protect a connected vacuum gauge from refrigerant contamination. Since the second ball valve is integrated into the VCRT, you no longer need to add a fitting to gain an isolation valve, which increases bulk and introduces a new potential leak point.

Made to Fit your System
All three Fieldpiece ac valve core removal tools come standard with a 1/4” service port fitting that may be swapped with an optional 5/16” fitting on the jobsite. You no longer need to purchase and haul additional VCRTs to accommodate different system ports, simply keep the swappable fitting in your toolkit. Fieldpiece VCRTs are the right tool, every time.

Thumbs up!
Inserting a core when a system is pressurized can be awkward, except when you have a comfort spinner! The VC1G and VC2G tools feature a rubber-coated, free-spinning cap that lets you use your thumb to hold the capture rod in place, against pressure and easily thread the core with your other hand. Another tech-friendly feature from Fieldpiece.

It’s a Fieldpiece
The VCRT lineup is another addition to our arsenal of rugged tools designed to make life easier for technicians everywhere. We stay committed to innovating in the HVACR industry and providing tools and instruments that survive the test of time while making jobs easier, faster and better.

Fieldpiece is always looking for innovative ways to make tech’s job easier, faster and better, and the combination of Job Link Probes and the Job Link System App do just that. Did you know that you can now use these tools to conduct a temperature compensated, nitrogen pressure leak test? Let’s walk through when to run a pressure test and some of the key steps in the process.

If you’re conducting a service call and have made repairs on a system, it’s important to make sure that it’s a clean, dry, and tight system – especially if you brazed new copper, added flared connections, or repaired other mechanical connections. A nitrogen pressure leak test is an excellent way to ensure that the system doesn’t have any leaks before charging it.

It’s recommended to run a pressure test, also called a tightness test, after a leak has been detected and repaired, or on new installs before charging with refrigerant. The test fills the system with nitrogen under pressure to determine whether it can hold that pressure over time, verifying there are no leaks. Nitrogen is an inert gas and is much safer and cheaper to use than refrigerant.

Before adding nitrogen and conducting a pressure test, record the initial pipe temperature and determine the length and volume of the tubing that is being filled to calculate the amount of nitrogen you will need. Then, make sure there aren’t leaks at the Schrader cores. You should also test your hoses and anything else connected to the system during the test.

Start by purging the system with nitrogen. This is different than flowing nitrogen – that’s at a much lower pressure. Purging allows nitrogen to flow into one side of the system and then out the other. This displaces all excess oxygen and air in the piping. Since you’re working with gas under pressure, be sure to work safely. Any gas under high pressure should be handled carefully and transported per the Department of Transportation guidelines.

After purging, replace the valve cores if you removed them, and attach a pressure regulator to the nitrogen tank and a charging hose to the service port. Be sure to use a regulator that is made for nitrogen and properly sized for the target pressure. Attaching a Job Link® System JL3PR Pressure Probe to the system can offer additional accuracy compared to the standard regulator dial. To monitor temperature, connect a Fieldpiece JL3PC Job Link® System Pipe Clamp to the system. Note that you can also use your Fieldpiece SMAN® digital manifold to run a nitrogen pressure test.

Once the system is prepared, start to slowly pressurize the system. Start with 100 psi and let the system sit for a minute. Then add another 100 psi and let it sit again. Typically, the recommended test pressure range falls within 200-600 psi, but check the system manufacturer’s specifications. If you’re pressurizing the low side of the system, use the manufacturer’s rated test pressure. Note that a stepped process that gradually increases pressure is not only safer, but it can also prevent wasting time and nitrogen.

Once the system is under pressure, isolate it by removing the charging hose and capping the Schrader port. If you’re working on a residential system, let it sit for 30 to 60 minutes. Some larger, commercial systems require a nitrogen pressure test to sit for 24 to 48 hours. Check with the manufacturer’s recommendations for the exact time needed.

If the system needs to sit for an extended period, temperature fluctuations in the environment will affect the pressure of the nitrogen in the system. Make sure to compensate for these changes in pressure before concluding that a system is leaking. Note that the new pressure test feature in the Job Link System App compensates for temperature fluctuations, as does the Fieldpiece SMAN digital manifold.

If you see a drop in the temperature compensated pressure over time, it means there is a leak. Bubble test every fitting and connection to find the source of the leak. This includes every field-fabricated joint in the system. Any of these could be a potential leak point.

When performed correctly, a nitrogen pressure test is an easy and safe way to determine if a system can be charged with refrigerant. Download the latest Fieldpiece Job Link ® System updates from the app store to include the nitrogen pressure test features. Learn more at www.Fieldpiece.com.