Butterfly valves are widespread in many industries to regulate fluid flow through piping systems. They feature a round disk that rotates within the valve body to either block or allow flow. Butterfly valves derive their name from how the cylindrical disk and shaft resemble the wings of a butterfly. Proper operation of a butterfly valve depends on an effective handle to rotate the disk and control flow. This guide will examine butterfly valve handles in greater detail.
Types of Handles
There are a few common types of handles used for butterfly valves:
Lever Handle – A simple lever that protrudes from the valve body acts as the handle. It allows the user to physically rotate the valve disk with minimal effort. Lever handles are common on smaller butterfly valves up to 6 inches.
Chainwheel Handle – Larger butterfly valves usually employ a chainwheel handle. This consists of a large circular wheel connected to the valve shaft via a chain or gear mechanism. The wheel can be turned by hand to operate valves remotely or in hard-to-reach areas. Chainwheel handles provide excellent leverage for valves 8 inches and larger.
Square Handwheel – Similar to a chainwheel but with a squared-off shape, a square handwheel allows users to get a firm grip and open/close the valve with two hands if needed. They are durable for both indoor and outdoor use.
Automated Actuators – For applications requiring remote or automated control, an electric, pneumatic, or hydraulic actuator replaces the manual handle. Actuators provide powerful torque to reliably operate very large butterfly valves or those in demanding service conditions.
Handle Design Considerations
Several factors must be considered when selecting and designing a handle butterfly valve:
Valve Size – Larger valves over 8 inches generally need a chainwheel or automated actuator to generate sufficient rotational torque. Smaller valves under 6 inches can use compact lever handles.
Service Conditions – Handles exposed to extreme weather, corrosion, or hazardous substances may require special corrosion-resistant materials. Tight spaces may necessitate compact designs.
Manual vs Automated Operation – Automated actuators are needed for remote valve control while manual handles allow direct on-site operation.
Locking – Some applications may require a handle that can be securely locked in the open or closed position to prevent unintended movement.
Ergonomics – Handle shape, size, and gearing must provide comfortable, balanced operation without straining users. Lever handles ease control better than heavy handwheels.
Visual Indication – Color-coding or tags on the handle can visually indicate the current valve position at a glance. This is important for safety processes.
Materials & Durability – Handles endure wear from frequent use, so they must be made from durable, corrosion-resistant alloys suited for the installation environment.
Valve Padlocking
For butterfly valves installed in areas accessible to the public or in industrial plants where process flows need to be regulated, padlocking the valve handle provides an important layer of security. Here are some reasons padlocking is commonly used:
Prevent accidental or unauthorized valve operation – Critical flows should not be disturbed without approval.
Lock valves in required steady operating positions – Isolate or regulate specific processes without risk of changes.
Perform maintenance safely – Lock out valves before working on connected equipment to avoid hazardous conditions.
Enforce workplace safety protocols – Padlocks help enforce procedures like confined space entry permits.
Deter theft or damage – Deters vandalism or tampering that could disrupt operations or endanger people.
Control regulated substances – For valves handling chemicals, gases or liquids where diversion poses risks.
Padlocks secure directly to the valve handle or gearing so it cannot be rotated without first removing the lock. This ensures valves remain in their intended state until unlocked by authorized personnel. Valve position indicators distinguish open from closed states while locked.
Handle Maintenance
Properly maintained handles enable reliable long-term valve operation. Periodic inspection and maintenance helps handles last as long as the valve itself. Common tasks involve:
Lubricating moving parts like chainwheels or gear mechanisms to prevent wear and corrosion buildup
Checking for loose, worn or damaged components and replacing as needed before failure occurs
Cleaning handles of process deposits, moisture or debris accumulation that could affect movement
Repainting or recoating to protect against environmental degradation for corrosion resistance
Exercising infrequently used handles to confirm smooth operation and identify maintenance needs early
Followingkit regreasing/lubrication schedules as suggested by the handle manufacturer
Recording handle condition, repair history and any noted issues in maintenance management systems
By keeping handles in good working order through minor upkeep, costly repairs stemming from neglect can be avoided. Proper handling ensures valves perform safely and reliably during their design service life.
In summary, the handle comprises a vital yet often overlooked component that determines how operators interface with butterfly valves. From design to maintenance, applying best practices for handles optimizes safety, control and long-term usability of these flow control devices.