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This episode is the first of a 10-part "CO2 Unfiltered" series, where we're joined by Ernesto Rodriguez to discuss hermetic CO2 pumps. Ernesto has decades of practical knowledge to help technicians understand how CO2 pumps really work and why so many failures can be prevented through proper design and installation. Here, we cover pump selection and sizing, and troubleshooting, including how to recognize cavitation and flash gas, avoid common piping mistakes, optimize pump performance, and commission CO2 pumps with confidence.
In this episode, we discuss:
(01:15) Introduction to CO2 pumps and why they matter
(04:50) Internal vs. external recirculation systems
(09:20) Pump construction and hydrostatic bearing lubrication
(15:45) Variable frequency drives and operating at the correct pump curve
(19:20) Recirculation rates and cascade system applications
(24:15) Pump sizing fundamentals, NPSH, and avoiding cavitation
(33:45) Flow regulation, differential pressure regulators, and system balance
(46:30) Installation best practices, suction piping, elbows, and insulation
(55:00) Proper pipe sizing and maintaining flow velocity
(01:01:15) Multiple pump installations and preventing turbulence
(01:09:15) Startup, commissioning, and maintenance checks
(01:12:30) Troubleshooting cavitation, flash gas, vibration, and pump failures
Helpful Links & Resources:
Episode 285. CO2 Experts: Transitioning to CO2 as a Service Technician Q & A with Andrew Freeburg
Episode 243. Step-By-Step Walkthrough of a CO2 Service Call with Patrick Gregory
Episode 227. Getting to Know Transcritical CO2 Supermarket Refrigeration Systems with Kevin Mullis
