Description

The Armstrong inverted bucket—the most reliable steam trap known—provides efficient condensate drainage of virtually all types of steam-using equipment. The 880 Series combines this reliability with a tough cast iron package and an integral strainer. These traps operate efficiently for longer periods, providing solid energy savings and lower replacement/labor costs.

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 discharge orifice is located at the top of the trap, dirt cannot collect on the seat. Small particles are held in suspension until discharged by the purging action when the bucket sinks.

Features

• Energy Efficient: 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.
• Water Hammer Resistant: The inverted bucket design is naturally resistant to water hammer.
• Side Inlet/Outlet: Horizontal installation for easy piping.
• Durable: Hardened chrome steel (17-4PH) valve and seat for erosion resistance.
• Repairable: All Armstrong cast iron inverted bucket traps are repairable for maintenance savings.

Operating Conditions

Parameter	Value
Max Allowable Pressure (Vessel Design)	250 psig @ 450 °F (17 bar @ 232 °C)
Max Operating Pressure (880)	150 psig (10 bar)
Max Operating Pressure (881, 882, 883)	250 psig (17 bar)
Connections	Screwed NPT, BSPT; Flanged options available

Materials

Component	Material	Standard
Body	Cast Iron	ASTM A48 Class 30
Internals	Stainless Steel	304
Valve and Seat	Hardened Chrome Steel	17-4PH
Strainer	Stainless Steel	304

Options

• CV: Internal stainless steel check valve
• T: Thermic vent bucket
• LV: Large vent
• BVSW: Scrub wire (for gas service)
• BD: Blowdown connection (NPT)

Dimensions & Weights (Approximate)

Model	Connections	Test Plug	A	B	C	D	E	Bolts	Weight lb (kg)
880*	1/2", 3/4" (15, 20 mm)	1/4" (6 mm)	3-3/4" (95.2 mm)	6-1/16" (154 mm)	5" (127 mm)	3-7/16" (87.3 mm)	3/8" (9 mm)	6	5-1/2 (2.5)
881	1/2", 3/4", 1" (15, 20, 25 mm)	1/4" (6 mm)	3-3/4" (95.2 mm)	7-1/16" (179 mm)	5" (127 mm)	4-7/16" (113 mm)	3/8" (9 mm)	6	6 (2.7)
882	1/2", 3/4" (15, 20 mm)	1/2" (15 mm)	5-5/8" (142.9 mm)	9-3/8" (244 mm)	6-1/2" (165 mm)	5-3/4" (146 mm)	3/8" (9 mm)	6	15-1/2 (7.0)
883	3/4", 1", 1-1/4" (20, 25, 32 mm)	3/4" (20 mm)	7" (177.8 mm)	12-3/8" (314 mm)	7-7/8" (200 mm)	7-3/8" (187 mm)	1/2" (15 mm)	6	31 (14.1)

Legend: A = Flange Diameter, B = Height, C = Face-to-Face, D = Bottom to CL Inlet, E = Blowdown Connection.*Note: Add suffix "CV" to model number for internal check valve, "T" for thermic vent bucket.

Capacity Charts

The charts below show the cold water capacities for different models at various differential pressures.

Model 880 Capacity

Model 881 Capacity

Model 882 Capacity

Model 883 Capacity

How to Order

Specify:

1. Model number
2. Size and type of pipe connection
3. Maximum working pressure or orifice size
4. Any options required