What arrangement is necessary for condensate removal in a steam heating system?

In a steam heating system, effective condensate removal is critical for the system's efficiency and operation. Free drainage from units is essential because, during the steam heating process, steam condenses back into water (condensate) as it releases heat to the environment. If this condensate is not drained effectively, it can create a variety of operational problems including water hammer, reduced heating efficiency, and increased risk of damage to the heating units.

When there is free drainage, the condensate can flow back to the boiler or be discharged through a drain line without obstruction. This helps maintain the proper functioning of the system by ensuring that steam generating equipment can continuously operate without interruption from water accumulation. The design of the system must account for gravity and ensure that all parts of the steam heating units are sloped correctly to allow for the free flow of condensate towards the drainage point.

Other arrangements, such as partial blockage, closed pathways, or high-pressure zones, could lead to inefficiencies and potential hazards within the system, making free drainage the necessary and correct choice for condensate removal in a steam heating system.