The Armstrong 881 Cast Iron Inverted Bucket Steam Trap features a built-in integral strainer and higher operating pressure capability for medium-pressure steam systems. Built with a cast iron body rated to 250 psig at 450°F (17 bar at 232°C), the Model 881 handles capacities up to 4,400 lb/hr (2,000 kg/hr) with a maximum operating pressure of 250 psig (17 bar). The integral strainer eliminates the need for a separate line strainer, reducing installation costs and potential leak points.
Like all Armstrong inverted bucket traps, the 881 uses a free-floating stainless steel mechanism with no fixed pivots to create wear or friction. The discharge orifice is surrounded by a water seal, preventing live steam loss. Automatic air venting is provided by a small vent hole in the bucket, delivering continuous air and CO₂ venting at steam temperature for efficient system startup.
Key Features
- Integral strainer for built-in protection against dirt and scale
- Free-floating stainless steel inverted bucket mechanism
- 250 psig maximum operating pressure for medium-pressure systems
- Continuous air and CO₂ venting at steam temperature
- Water seal prevents live steam loss
- Field-repairable internals
- Resistant to water hammer
Applications
Suited for drip, tracer, and process applications in medium-pressure steam systems where pipeline debris is a concern. Available with screwed NPT and BSPT connections in 1/2″ (15 mm), 3/4″ (20 mm), and 1″ (25 mm) sizes.
