Is this part compatible with natural gas heaters

the Lennox 51W15 is the approved direct replacement for legacy part numbers 51W1501

part of the Lennox 36T series

The lead-free construction and robust internal components offer long-term performance in high-cycle environments where thermal expansion and fluid compatibility are critical factors for system uptime and mechanical integrity

Armstrong International 75A3 Trap 30067439-890 Is this part compatible withThe Armstrong International 75A3 Trap is a high performance 3 4" NPT steam trap designed for industrial heating applications requiring efficient condensate removal and rapid air venting. As part of the prestigious Series A Cast Iron Float & Thermostatic Steam Trap family, this unit features a robust cast iron body and a thermostatic air vent equipped with a balanced pressure phosphor bronze bellows caged in stainless steel. Specifically engineered for