Siemens 277-05921 Flowrite 599 Series 2-Way Normally Open 3-Inch Flanged Valve Assembly with 8-Inch Pneumatic Actuator

The Siemens 277-05921 is a Flowrite 599 Series 2-way, normally open pneumatic valve assembly designed for precise flow control in commercial HVAC hydronic and steam systems. This pre-assembled unit pairs a 3-inch, ANSI Class 250 cast iron flanged valve body with an 8-inch pneumatic actuator, delivering reliable modulating control with a 5 psi actuator span.

Key Features:

• Valve Configuration: 2-Way, Normally Open (N/O), stroke-globe style
• Flow Coefficient: 100 Cv with equal percentage flow characteristic for precise modulating control
• Pipe Size & Connection: 3-inch flanged end connections, ANSI Class 250 rated
• Valve Body Material: Cast iron, ASTM A126 Class B
• Trim Material: Stainless steel — body trim, stem (ASTM A582 Type 303 stainless steel), bronze plug, single-seat configuration
• Packing: EPDM O-rings for standard duty sealing
• Actuator: 8-inch pneumatic actuator with 3/4-inch (20 mm) stroke
• Leakage Rate: Class IV (0.01% of Cv)
• Rangeability: Greater than 100:1 for excellent turndown control
• Compatible Media: Water, water with antifreeze, saturated steam
• Operating Temperature: 20°F to 250°F (standard/normal temperature duty)
• Warranty: 60 months

The 277-05921 is part of Siemens' proven Flowrite AP 599 Series, engineered for dependable, long-service performance in demanding HVAC plant environments. The equal percentage characteristic provides smooth, stable modulating control across the full flow range, making this assembly well-suited for chilled water, hot water, and steam coil applications in commercial buildings.