The Armstrong TAVB-2 and TAVB-3 are combination thermostatic air vents and vacuum breakers ideally suited for steam-filled vessels with modulating controls. The TAVB series will vent air and other non-condensables from vessels such as shell and tube heat exchangers, jacketed kettles, and steam coils during their operation. It will also break the vacuum that forms during steam control modulation.

This balanced pressure air vent responds to the pressure-temperature curve of steam, and the soft-seated vacuum breaker responds to 2" H2O of vacuum. The combination of the thermostatic air vent and vacuum breaker into one unit allows for easy installation of both devices critical to proper operation of process and heating units.

Features

• Maximum allowable pressure: 300 psig (20 bar)
• Maximum allowable temperature: 365°F (185°C)
• Maximum working pressure: 150 psig (10 bar)
• Construction: All stainless steel welded construction
• Connections: NPT connections

Installation Guidelines

Installation Position

Armstrong thermostatic air vents should be installed at the highest point on a steam chamber, with the air vent located above the chamber. This will minimize the possibility of any liquid carryover, and air can be vented to atmosphere without a drain line.

Flow Direction

FLOW arrows on the vent label must correspond with the flow of the vented air.

Series TAVB vents may be used to vent air from steam chambers, coils, and air handlers into the atmosphere. Any air accumulating in the steam inlet will be automatically vented at slightly below steam temperature throughout the entire operating pressure range. The vacuum breaker opens at the end of each cycle allowing rapid drainage to the trap of any remaining condensate.

Typical Applications

Figure 1. Installation on a stationary cooking kettle.

Figure 2. Installation on a retort.

Figure 3. Installation on a sterilizer.

Figure 4. Installation on a vulcanizer.

Figure 5. Installation on jacketed kettles.

Figure 6. Installation on a unit heater.

Physical Data and Dimensions

Physical Data	TAVB-2	TAVB-3
Pipe Connections (Thermostatic Air Vent)	1/2" (15 mm)	3/4" (20 mm)
Pipe Connections (Vacuum Breaker)	3/8" (9.5 mm)	3/8" (9.5 mm)
"A" (Diameter)	2-1/4" (57 mm)	2-1/4" (57 mm)
"B" (Height)	4-5/8" (117 mm)	4-11/16" (119 mm)
"C" (¢ Inlet to Face of Vacuum Breaker)	2-1/8" (54 mm)	2-1/8" (54 mm)
Weight	1 lb (0.45 kg)	1-1/4 lb (0.57 kg)
Maximum Allowable Pressure (Vessel Design)	300 psig @ 365°F (20 bar @ 185°C)	300 psig @ 365°F (20 bar @ 185°C)
Maximum Operating Pressure	150 psi (10 bar)	150 psi (10 bar)
Discharge Orifice Size	3/16"	3/16"

List of Materials

Name of Part	Material
Body	304-L Stainless steel
Connections	304 Stainless steel
Balanced Pressure Thermostatic Air Vent	Stainless steel and bronze with phosphor-bronze bellows, entire unit caged in stainless steel
Gasket	Copper clad non-asbestos
Vacuum Breaker Body	303 Stainless steel
Valve	Stainless steel
Spring	302 Stainless steel
"O" Ring	EPDM
Screen	Stainless steel