Armstrong 5000 Series forged chrome-moly steel inverted bucket steam traps are designed for vertical installation with a choice of screwed, socketweld, or flanged connections. 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, preventing live steam loss. Automatic air venting is provided by a small vent hole in the bucket, ensuring continuous automatic air and CO₂ venting at steam temperature.

Inverted bucket traps drain continuously, although discharging intermittently, to prevent condensate backup. They are also resistant to water hammer.

Operation on Superheat

A normally operating bucket trap is filled with saturated steam and condensate. Superheated steam can enter only as fast as the steam inside can condense. As a result, the temperature of the trap is at (or slightly below) saturated steam temperature, regardless of the degree of superheat.

Features and Working Principle

For Superheat Service

When using the 5000 Series for superheat service, observe the following recommendations:

1. Don’t oversize the orifice; a restricted orifice may be advisable.
2. Specify a burnished valve and seat and an extended inlet tube and check valve.
3. Provide a drip leg of adequate diameter and length.
4. Provide a generous length (600-900 mm / 2'-3') of inlet piping, with the trap below the main.
5. Don’t insulate the trap or the inlet piping.

Materials

Component	Material
Body	ASTM A182 F22 Class 3 Forged Steel
Internals	All stainless steel – 304
Valve and seat	Titanium

Dimensions and Weights

Model No. (Screwed/SW)	5133G	5155G
Model No. (Flanged)	5133G-FW	5155G-FW
Pipe Connections (mm)	15, 20, 25	20, 25, 32
"A" Flange Diameter (mm)	216	264
"B" Face-to-Face Screwed/SW (mm)	362	412
"BB" Face-to-Face Flanged (mm)	479*	530*
"G" Body Outside Diameter (mm)	146	194
"K" C Outlet to C Inlet (mm)	33.3	44.4
Number of Bolts	8	10
Weight Screwed/SW kg (lb)	44.5 (113)	77.6 (171)
Weight Flanged kg (lb)	47.6 (120)	83.9 (185)

Note: "BB" dimensions shown are for 1" conn. Class 1500 flanged No. 5133G-FW and 1-1/4" conn. Class 1500 flanged No. 5155G-FW.

Capacities

Pressure-Temperature Rating

Model No.	Max. Operating Pressure (Saturated Steam)	Max. Allowable Pressure at 371°C (700°F)	Max. Allowable Pressure at 538°C (1000°F)
5133G	103 bar (1500 psig)	146 bar (2120 psig)	64 bar (930 psig)
5155G	124 bar (1800 psig)	174 bar (2520 psig)	76.5 bar (1110 psig)

Note: Maximum operating pressure to be marked on nameplate will be determined by actual orifice used.

Options

• Internal Check Valves: Spring-loaded stainless steel, screwing into an extended inlet tube having a pipe coupling at the top. May result in slightly reduced capacities.
• Screwed Connections: Available in all sizes for pressures of 63 bar (900 psig) or less. Higher pressures require socketweld or flanged connections.

Maintenance

Equipment under pressure

Operating temperature > 100°C. Make sure the trap is cold before handling!

Internals Maintenance:

1. Remove the complete trap from the steam line.
2. Unscrew bolts and nuts and lift the cap.
3. Clean or replace the bucket or mechanism (valve and seat).
4. The mechanism should be adjusted so that when correctly aligned, the lever can be moved sideways the same distance to the right as to the left. If the guide pin is not in the middle of the orifices, adjust by slightly hitting with a hammer.
5. Replace the gasket.
6. Put the cap back on the body and screw bolts and nuts.

Important Note: The type and material of bolts must not be changed.