Butterfly valves are widely used industrial valves to regulate flow in pipe systems. Based on their disc design and seat configuration, butterfly valves can be categorized into ggg50, lt and U type valves.
Each variety has distinct advantages suited for certain applications and operating conditions. Meanwhile, they have distinct constructions tailored for specific pressure, temperature, sealing and flow control needs across industries like water supply, chemical processing, energy, HVAC, and general engineering. This article will compare ggg50, lt and U type butterfly valves in terms of their construction, performance attributes, use cases and selection criteria.
Construction of ggg50, lt and U Type Butterfly Valves
- Firstly, ggg50 butterfly valve has offset disc centers and utilize resilient seats that allow tight shutoff despite disc deflection. ggg50 denotes the distance of the disc center offset from the seat centerline.
- Secondly, lt butterfly valve has concentric centered discs supported on both sides. They use metal seats and rely on disc to seat contact for tight sealing. lt denotes the diameter of the pipe to which the valve can be installed.
- Thirdly, U type butterfly valve also has concentric disc centers but use resilient U-cup seals inserted into the valve body liner. This gives both metal-to-metal and soft seal contact.
Sealing ability: The resilient seats in ggg50 and U type valves allow bubble-tight shutoff even at high pressures and temperatures. lt valves can experience seat passing leaks.
- Pressure rating: lt type valves offer the highest pressure capacity of up to Class 600. ggg50 is typically Class 150. U type is in between at Class 300.
- Temperature range: ggg50 and U type handle temperatures from -40°F to 250°F. lt type can withstand higher temperatures.
- Flow regulation: lt valves offer more precise flow control compared to ggg50 and U types which are more for on/off applications.
- ggg50: Used extensively in water and wastewater pipelines for reliable shutoff against differential pressure. Also used in chemical, oil and gas lines.
- lt: Ideal for flow control in high pressure steam lines, compressor discharge, and power plant piping. Also used in cryogenic and high temperature applications.
- U type: Suitable for water treatment plants, swimming pools, HVAC systems, and service lines exposed to grit that can damage seats. Provides shutoff while easing seat wear.
- Operating pressure/temperature: lt for extremely high pressures and temperatures; ggg50 for moderate conditions.
- Shutoff requirements: U type and ggg50 for zero-leakage shutoff; lt where minor seat leakage is permissible.
- Flow control needs: lt for modulating flow; others for on/off applications.
- Media characteristics: U type for abrasive media that causes seat wear; ggg50 for clear fluids.
- Cost: U type priced in between ggg50 and lt types. lt most expensive.