Armstrong International 15BI3 3/4″ NPT In-Line 15 PSI Series B Cast Iron F&T Steam Trap

Description

The Armstrong International 15BI3 is a Series B Cast Iron Float & Thermostatic (F&T) Steam Trap engineered for reliable, continuous condensate discharge in low-pressure steam systems. Featuring a 3/4″ NPT in-line connection, this trap is designed for straightforward installation in-line with existing piping, minimizing installation time and reducing the need for additional fittings.

How It Works

Float & Thermostatic steam traps use a float mechanism to continuously discharge condensate as it forms, while the integrated thermostatic air vent automatically purges non-condensable gases such as air at startup and during operation. This dual-action design promotes faster system warm-up, improved heat transfer efficiency, and reduced risk of water hammer.

Key Features

• Series B Cast Iron body construction for durability in demanding steam applications
• 3/4″ NPT in-line connection for easy, direct piping installation
• 15 PSI maximum operating pressure rating
• 7/32″ orifice for precise condensate flow control
• Integrated thermostatic air vent for automatic purging of non-condensable gases
• Continuous condensate discharge — no condensate backup or slugging
• Suitable for heating coils, unit heaters, heat exchangers, and similar low-pressure steam equipment

Specifications

• SKU: 15BI3
• Brand: Armstrong International
• Series: Series B
• Body Material: Cast Iron
• Connection Size: 3/4″ NPT
• Connection Type: In-Line
• Maximum Operating Pressure: 15 PSI
• Orifice Size: 7/32″
• Trap Type: Float & Thermostatic (F&T)

Application

Ideal for low-pressure steam heating systems in commercial and industrial environments. The Armstrong 15BI3 is well-suited for use on unit heaters, fan coil units, heat exchangers, and process heating equipment operating at or below 15 PSI steam pressure. Armstrong International’s proven F&T trap design ensures long service life and minimal maintenance.