Pulmonary vein three and five in the healthy population. The two left lobar veins may be united as a single pulmonary vein in about 25% of people; the two right veins may be united in about 3%. The pulmonary veins play an essential role in respiration, by receiving blood that has been oxygenated in the alveoli and returning it to the left atrium. As part of the pulmonary circulation they carry oxygenated blood back to the heart, as opposed to the veins of the systemic circulation which carry deoxygenated blood. A rare genetic defect of the pulmonary veins can cause them to
Oxygenated treatment corrosion. When OT is used, conductivity after cation exchange (CACE) at the economiser inlet must be maintained below 0.15μS/cm this can be achieved by the use of a condensate polisher. Oxygenated treatment Oxygenated treatment (OT) is a technique used to reduce corrosion in a boiler and its associated feedwater system in flow-through boilers. With oxygenated treatment, oxygen is injected into the feedwater to keep the oxygen level between 30-50 ppb. "Common injection points are just after the condensate polisher and again at the deaerator outlet." This forms a thicker protective layer of hematite (FeO) on top of the magnetite. This