Armstrong 15-B6 Float and Thermostatic Steam Trap

Armstrong 15-B6 Float & Thermostatic Steam Trap is a 1-1/2 in NPT cast-iron B-series trap designed for horizontal installation, delivering reliable condensate drainage in steam systems while withstanding live steam conditions. It is rated for a maximum operating pressure (MOP) of 15 psi and a maximum allowable pressure (MAP) of 175 psi, with a maximum service temperature of 377°F, making it suitable for moderate-pressure steam lines and condensate-rich runs. The trap handles up to 4,200 lb/hr of condensate flow and uses a 1/2 in orifice to regulate drainage, enabling fast response to varying condensate loads without excessive steam loss. Its screwed (NPT) 1-1/2 in connections support straightforward field installation and standard piping compatibility, typically configured for horizontal flow direction. The float-and-thermostatic mechanism separates condensate from steam while venting air, contributing to efficient heat transfer and reducing water hammer risks in boilers, heat exchangers, and steam mains. Built to endure industrial environments, this model aligns with Armstrong’s reputation for durable, back-pressure tolerant traps within the B-series family. Commonly referenced in distributor catalogs as model 15B6 (D1175-11), it’s listed by major suppliers for applications needing a robust, mid-size trap that balances condensate removal with minimal steam loss. In short, the Armstrong 15-B6 provides a proven, inline solution for draining condensate in 1-1/2 inch steam lines while meeting the 15 psi operating constraint and 175 psi maximum pressure rating, backed by a cast-iron body and a 377°F temperature ceiling.