Q84Y-25

Engineer's Selection Guide: Steam Traps

Steam traps discharge condensate and non-condensable gases while retaining live steam. Selection depends on the trap type (mechanical, thermodynamic, thermostatic), load, pressure, and whether continuous or intermittent drainage is required. Proper sizing prevents premature failure and energy loss.

• For modulating, continuous condensate load on process equipment a float-and-thermostatic (mechanical) trap handles varying load without blowing live steam; for remote, maintenance-free points a thermodynamic disc trap suits but needs the correct pressure rating.
• Never apply a thermodynamic trap below its rated differential or it will cycle rapidly and fail; on steam-tracing lines thermostatic (bellows) traps are the usual choice for tight temperature control.

Guidance reflects general engineering practice for steam traps; confirm against the project specification and applicable standards before procurement.