CO2 leak from the CO2 pump when starting FDM - WKB109794

SYMPTOMS

• CO2 leak from the CO2 pump when starting the FDM of the SFC-Prep system

 

ENVIRONMENT

• SFC Prep 15

• SFC Prep 30

• Investigator SFC System

• MV-10

• FDM

 

 

CAUSE

Carbon dioxide may temporarily leak for a few seconds after the FDM CO2 pump starts to pump.

 

Following reasons can be considered.

• Deterioration of CO2 pump seal
• Problem due to the characteristics of CO2 pump in the SFC system

 

Pump seals on CO2 pumps have been found to deteriorate slightly faster than pump seals on LC pumps.

This is because the CO2 pump needs to cool the CO2 pump head due to the characteristics of the SFC system.

The pump seals become hard due to these cooling actions, and friction with the piston accelerates the deterioration of the pump seals.

Also, by cooling the pump head, the pump seal is also cooled and may shrink slightly.

During this, CO2 leaks from a small gap.

This CO2 leak often occurs when starting the CO2 pump.

However, if the CO2 leak is temporary and the CO2 leak stops in about 30 seconds after the CO2 pump is started, there is no problem in operation.

The CO2 pump seal expands when pressure from CO2 is applied, and when it closely contacts with the pump head, CO2 leakage is eliminated.

 

FIX or WORKAROUND

• If the CO2 pump continues to leak for more than 1 minute after starting, it is recommended to replace the pump seal.

 

ADDITIONAL INFORMATION