In a steam heating system, where must the steam supply line be located relative to the return line?

In a steam heating system, where must the steam supply line be located relative to the return line?

• A. Below the return line
• B. Above the return line
• C. At the same level as the return line
• D. In front of the boiler

Answer: (B)

In steam heating, keeping the steam supply line above the return line helps gravity do the work of moving condensate back to the boiler and keeps the steam line dry. If the supply line is higher, condensate that forms in the system will tend to stay in the lower return line and drain back to the boiler rather than pool in the steam line, which reduces the risk of water hammer and ensures consistent steam flow to the radiators. Placing the supply below or at the same level as the return could allow condensate to back up into the steam line and disrupt steam delivery. The relative position in front of the boiler doesn’t address this drainage and flow behavior.

In steam heating, keeping the steam supply line above the return line helps gravity do the work of moving condensate back to the boiler and keeps the steam line dry. If the supply line is higher, condensate that forms in the system will tend to stay in the lower return line and drain back to the boiler rather than pool in the steam line, which reduces the risk of water hammer and ensures consistent steam flow to the radiators. Placing the supply below or at the same level as the return could allow condensate to back up into the steam line and disrupt steam delivery. The relative position in front of the boiler doesn’t address this drainage and flow behavior.