What is the difference between a spring-loaded and a double ball and seat check valve on an ACQUITY UPLC BSM? - WKB14576

ENVIRONMENT

• ACQUITY UPLC Binary Solvent Manager (BSM)
• nanoACQUITY UPLC Binary Solvent Manager

ANSWER

Spring-loaded check valves' reliability comes from the creation of seal force dictated by the tension of the spring. Spring-loaded check valves are positioned on the primary actuator. If the primary pump CV fails, the head will not be able to deliver solvent.

Double ball and seat (DBS) check valves (CVs) are the most common. The valve in on the accumulator actuator. If one of the seals fails in a DBS, the other should allow the pump to work correctly. If the DBS CV fails, there could be variability in retention time or pressure fluctuations.

With a serial flow pump, the primary must fill to deliver solvent to the accumulator. The primary pump head actually acts like a check valve; even if the accumulator CV fails, the flow will still only be able to go in the direction of the column.

ADDITIONAL INFORMATION

Passive primary check valves may have long-term reliability impact, especially for bio applications using high salt buffers. Intelligent Intake Valves (i2V) were introduced for robustness and reliability but were not available on earlier generations of the BSM, which were fitted only for use with passive spring-loaded primary check valves.