The S-IVB also continued to thrust in a very low degree by venting gaseous hydrogen, to maintain propellants settled within their tanks and forestall gaseous cavities from forming in propellant feed strains. This venting also maintained Safe and sound pressures as liquid hydrogen boiled off from the gas tank. https://embeddedai10852.bluxeblog.com/66031451/detailed-notes-on-apollo-mcu