Steam Trap Loss Estimator

Quantifies annual steam loss and dollar cost from a population of failed steam traps using Napier’s orifice flow equation. Required CSV columns: trap_id, service, set_pressure_psig, orifice_in, status, hours_per_year. Status values: OK, BLOWN, LEAKING, COLD.

CSV Input

Fuel cost ($/MMBtu)

Steam latent heat (Btu/lb)

Leak fraction (BLOWN basis)

Method: Napier’s equation per Spirax Sarco The Steam and Condensate Loop, Module 2.4 — W (lb/hr) = 24.24 · P_abs (psia) · D_orifice² (in²), where P_abs = P_set + 14.696 psi. BLOWN traps assume full Napier choked-flow discharge; LEAKING traps default to 40% of Napier per Spirax / DOE empirical guidance; COLD and OK traps contribute zero steam loss (COLD still flags downstream process impact). Annual cost = lb/yr · latent heat (default 1000 Btu/lb, accurate within 5% for 15–600 psig saturated service) · fuel $/MMBtu / 10⁶. Sources: Spirax Sarco Module 11.4 (trap testing), DOE Steam Tip Sheet #1, Armstrong Handbook N101, ASME PTC 39 (steam-trap performance test code). Does not credit condensate or flash-steam recovery.

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