13th Jun 2021
Tips for How to Prime an HPLC Pump
Why Is It Important To Prime an HPLC Pump?
It is important to prime your HPLC pump to ensure that only the solvent you want flowing through the pump is present. Therefore, when installing a new pump, taking a pump out of storage, or changing solvents, it is important to prime the HPLC pump.
The other reason you may need to prime your HPLC pump is to remove bubbles from the solvent line.
Tips for Priming an HPLC Pump
If your pump has a prime/purge valve, priming your pump is quite simple.Ensure all connections downstream of prime/purge valve are closed
- Ensure all connections downstream of prim/purge valve are closed.
Attach syringe to prime/purge valve
Open prime/purge valve (in the case of Chrom Tech pumps, you turn the knob counterclockwise one to two turns
Draw syringe back to prime. Draw approximately 20 mL of fluid
Press “Prime” button (or pump at max flow), continue to draw on syringe until no bubbles are seen
Close prime/purge valve
Press prime button (stop pumping solvent)
Remove syringe
What Is a Prime Purge Valve?
The prime/purge valve vents the flow to atmosphere and permits efficient priming of the pump. When the valve is closed (fully clockwise), high-pressure flow is directed to the outlet port. When the valve is opened (counterclockwise), pressure is vented, and flow exits through the drain port in the prime/purge valve assembly. Suction with a luer tip syringe at the port will purge air bubbles from the pump and reservoir lines (provided there are no open valves to lines downstream at the injector/column interface).
Don’t Have a Prime/Purge Valve? No Problem!
If you don’t have a prime/purge valve, you can still prime your HPLC pump with common laboratory HPLC Fittings. Simply remove the 10-32 HPLC fitting on the outlet check valve (10-32 thread is the standard outlet port on most models of HPLC pumps), insert a luer adapter (P-642), attach a luer syringe, and draw the mobile phase through the pump head as described above in the Tips for Priming an HPLC pump.
P-642 female luer adapter shown above
Chrom Tech HPLC Pumps Designed for Easy Maintenance
Maintenance is simple on Chrom Tech HPLC pumps since the items typically replaced are on the outside of the pump chassis. The inlet check valve is on the bottom of the pump head, and the outlet check valve is on the top of the pump head. Check valves are shown below in this exploded diagram of the pump head with the self-flush housing:
Chrom Tech pumps are equipped with our innovative Self Flush feature to provide continuous wetting of the piston. Using the self-flush system dramatically increases seal life and improves overall reliability by continuously flushing away buffer salts (or other harmful solvents) that could precipitate out and cause scratches on the piston and then premature seal failure—resulting in leakage.
For more tips, read our blog on HPLC Pump Care and Troubleshooting for best practices to keep your HPLC pump running trouble-free for years to come. 
Picture of Chrom Tech HPLC pumps used in a non-chromatography application.
Chrom Tech Pumps in a Production Facility for Over 20 years!
I recently had a conversation with the maintenance supervisor in charge of equipment uptime in the filtration production of a facility using Chrom Tech HPLC pumps to pump diluent to a catalyst to produce the fiber for their filters:
“We can trust that the Chrom Tech pumps are consistent every time. That is really the reason why we went with Chrom Tech in the beginning, and then again when we needed to purchase another pump diluent line, and service. When they asked us as techs (I was not a supervisor at the time) ‘if we get more diluent pumps, what is your preference?’ the decision was clear. Chrom Tech is always there, they have always supported us, we can get what we need.
If we e-mail or call, you always respond and that is important to us. The products are good, but the decision to work with Chrom Tech was based on our relationship. We know you will respond and help us.
It’s really about relationships. Chrom Tech has proven to be a great vendor to Cantel Medical/Medivators (formerly MinnTech) and it was a no-brainer to work with Chrom Tech when we needed to update our diluent line. We have 75 Chrom Tech pumps, and we chose to go back to Chrom Tech for more diluent pumps. The parts are readily available, the service is top notch, customer service is top notch… and, even when you can’t help us, you give us to someone that can. That’s what it’s all about in the service industry, which is what I consider the maintenance group, and Chrom Tech has always done a great job.”
Cody Bullis, Equipment Maintenance Technician Supervisor,
Medical Division, Cantel