411G/421 Series Inverted Bucket Steam Traps

Forged carbon steel for vertical and horizontal installation

For pressures to 1,000 psig (69 bar) . . .
Capacities to 1,300 lb/hr (590 kg/hr)

Armstrong Model 411G vertical installation and Model 421 horizontal installation offer smaller capacities at higher pressures.

A unique leverage system multiplies the force provided by the bucket to open the valve against system pressure. The mechanism is free-floating and has no fixed pivots to create wear or friction.

Because the mechanism is located at the top of the trap, no dirt can collect on the orifice. Small particles of dirt are held in suspension until discharged by the full differential purging action when the bucket sinks, pulling the valve off the seat.

The discharge orifice is surrounded by a water seal, which prevents live steam loss. Automatic air venting is provided by a small vent hole in the bucket.

Inverted bucket traps drain continuously, although discharging intermittently, allowing no condensate backup. They are also resistant to water hammer.

Model 421 adds the convenience and savings of in-line repairability and is designed to meet today’s energy-management requirements efficiently and economically over a long, trouble-free service life.