Weighted Counterbalance Butterfly Valve

When precise flow regulation and fail-safe closure are critical, a Counterbalanced Butterfly Valve delivers unmatched reliability. This design, often referred to as a Gravity Counterweight Butterfly Valve or Dead Weight Butterfly Valve, uses an external weight mechanism to provide consistent torque assistance, ensuring the disc moves to a predetermined safe position—normally closed—when power or actuation pressure is lost. By eliminating reliance on springs that can fatigue over time, the counterweight system offers decades of dependable service in demanding industrial environments such as water treatment, power generation, and chemical processing. Constructed with a one-piece shaft, robust disc, and replaceable seat, this valve handles pressures up to 300 psi and temperatures from -20°F to 450°F depending on material selection. The counterweight arm is field-adjustable, allowing operators to fine-tune closure speed and balance for specific media characteristics including slurries, steam, and corrosive fluids.

The Weighted Counterbalance Butterfly Valve integrates a rugged ductile iron or carbon steel body with an adjustable counterweight assembly engineered to deliver smooth, chatter-free performance. Every unit undergoes factory testing to verify seat leakage rates below API 598 standards and torque symmetry across the full 90-degree stroke. Below is a detailed breakdown of the standard technical parameters and material options available for this product line.

• Nominal diameters: 2″ to 48″ (DN50 to DN1200)
• Pressure ratings: Class 125, 150, and 300
• Face-to-face dimensions per API 609 Category A
• Actuation: gearbox, electric, pneumatic, or bare shaft with counterweight
• Adjustable counterweight arm with multiple weight plates for field tuning
• Seat retrofit capability without removing the valve from the line
• Fire-safe design to API 607 and ISO 10497 on request