A bypass plug is used on two-pipe oil systems; it is placed in the oil pump.

A bypass plug is used on two-pipe oil systems; it is placed in the oil pump.

• A. True
• B. False
• C. In the oil tank
• D. In the fuel line

Answer: (A)

The bypass plug is used to create an alternate flow path for the oil pump so the system can be primed, bled, or tested without forcing oil through the normal burner path. In a two-pipe oil system, you want the pump to be able to circulate oil even when the regular flow path (to the nozzle and through the regulator) is being serviced or closed. Placing the bypass plug in the oil pump does exactly that: it routes oil around the usual flow restrictions right at the source, inside the pump body, where the supply path and return path are controlled. If you put a bypass in the tank or in the fuel line, it wouldn’t affect the pump’s internal flow path and wouldn’t provide the necessary bypass during priming or testing. So the correct placement is inside the oil pump.

The bypass plug is used to create an alternate flow path for the oil pump so the system can be primed, bled, or tested without forcing oil through the normal burner path. In a two-pipe oil system, you want the pump to be able to circulate oil even when the regular flow path (to the nozzle and through the regulator) is being serviced or closed. Placing the bypass plug in the oil pump does exactly that: it routes oil around the usual flow restrictions right at the source, inside the pump body, where the supply path and return path are controlled. If you put a bypass in the tank or in the fuel line, it wouldn’t affect the pump’s internal flow path and wouldn’t provide the necessary bypass during priming or testing. So the correct placement is inside the oil pump.