Butterfly Valves: Discussing the Different Functions of DI, CI and HP Designs

Butterfly Valves: Discussing the Different Functions of DI, CI and HP Designs

Butterfly valves represent a flexible flow control solution utilized across many process industries. Their economical design and low torque operation enable usage in varied applications and fluid types. Within the butterfly valve category lay divisions defined by valve body and trim materials suited for a range of operating pressures and environments. Commonly specified variations include ductile iron, cast iron and high performance butterfly valves.

What Is The Shortcut O f Ductile Iron Butterfly Valves?

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Ductile iron butterfly valves, also called ductile iron (DI) butterfly valves, exhibit mechanically robust properties through their spheroidal graphite microstructure. DI bodies withstand shock loading and cyclic stresses better than cast iron alternatives. Pressure ratings range from 150-2500 psi depending if wafer, lug or groove end styles are selected. Internal and external epoxy coatings complement ductile iron’s natural corrosion resistance, expanding its versatility handling abrasive or corrosive fluids. DI butterfly valve find pervasive use for water, wastewater, and general industrial process isolation or throttling where suitable working pressures exist.

How To Understand The CI Butterfly Valves?

When lower operating pressures govern valve selection, cast iron (CI) butterfly valves offer a cost-effective option. Manufactured to ASTM A126 Class B standards, CI butterfly valve exhibit adequate strength for pressures under 150 psi. Their cast construction forms intricately shaped bodies ideal for complex configurations. Internally protective epoxy coatings enable usage with certain process services where corrosion presents less severe risks. Typical CI butterfly applications involve natural gas distribution, irrigation, or potable water supply below 100 psi.

High Performance Butterfly Valve Up To 3000 PSI

Specialized high performance (HP) butterfly valves employ fabricated or laminated construction permitting higher pressure specifications up to 3000 psi. Reinforced epoxy or rubber lined bodies withstand intensive fluid velocities and abrasive particulate matter better than CI and DI alternatives. HP butterfly trim utilizes rugged alloy steels or exotic alloys to resist wear in corrosive or erosive applications. These premium butterfly valves see niche service for oil & gas extraction, pulp & paper, or mining industries transporting slurries at elevated pressures.

Moving inside the valve, user-serviceable disc designs differentiate butterfly types further. DI and CI valves usually contain ductile or cast iron discs for economical operation at their respective pressure classes. One-piece investment cast discs offer self-centering stability. HP butterfly valve often utilize insert type discs constructed from resistant alloys tailored for severe services. Cut away seals along disc edges reduce leakages when throttling.

Conclusion Of Kinds Of Buterfly Valves

With DI, CI and HP variations available, engineers can match butterfly valves to projects spanning diverse industries and fluid conditions. Factoring application parameters like pressures, fluid characteristics, temperatures and flowrates ensures the proper material-rated butterfly valve style performs seamlessly as specified. Through prudent valve selection from varied butterfly product lines, fluid systems worldwide operate at maximum dependability for many years.