Types of Butterfly Valves – Working, Parts & Diagram Explained

Table of Contents

1. Introduction to Butterfly Valves
2. Common Butterfly Valve Types
3. Butterfly Valve Parts Explained
4. Butterfly Valve Working Principle
5. Butterfly Valve Diagram
6. Butterfly Valve Symbol & P&ID Use
7. Butterfly Valve HSN Code Reference
8. Butterfly Valve Uses Across Industries
9. Butterfly Valve Actuator & Automation
10. Stainless Butterfly Valve – Benefits & Applications
11. Delval Butterfly Valve – Brand Insight
12. FAQs

Introduction to Butterfly Valves

Butterfly valves are essential flow control devices used across a wide range of industries. Characterized by a rotating disc that allows or restricts fluid flow, these valves are compact, cost-effective, and suitable for various pressure and temperature conditions. The versatility of the butterfly valve lies in its many types, each designed to meet specific application requirements.

Common Butterfly Valve Types

There are several butterfly valve types based on design, material, and operation. The most commonly used include:

• Lug Type Butterfly Valve: Designed for dead-end service with threaded inserts for secure pipe connection. Useful for systems requiring frequent maintenance.
• Flanged Butterfly Valve: Integrated flanges provide a strong connection for high-pressure environments. Offers easy installation and removal.
• Double Flanged Butterfly Valve: Offers enhanced structural strength with flanges on both sides. Ideal for heavy-duty operations.
• Stainless Butterfly Valve: Made from stainless steel for superior corrosion resistance in food, pharma, and chemical industries.

Each type has its advantages and selection depends on operational needs, pressure ratings, and environmental conditions.

Butterfly Valve Parts Explained

A butterfly valve consists of several key components. Understanding these butterfly valve parts is critical for choosing the right valve and performing maintenance:

• Body: The outer casing that holds internal components together.
• Disc: The rotating part that controls flow.
• Stem: Connects the disc to the actuator or handle.
• Seat: Seals the disc against the valve body to prevent leakage.
• Actuator: Provides the motion needed to turn the disc.

Butterfly Valve Working Principle

The butterfly valve working principle is based on a quarter-turn rotation. As the actuator turns the stem, the disc rotates within the valve body. When the disc is parallel to the flow, the valve is fully open. When perpendicular, it's closed. Intermediate positions allow throttling. This simple operation provides fast shut-off and minimal pressure drop across the valve.

Butterfly Valve Diagram

A butterfly valve diagram helps visualize internal mechanisms and component alignment. Diagrams are essential in technical manuals and installation guides. They typically show the disc, stem, actuator, and sealing interface clearly.

Butterfly Valve Symbol & P&ID Use

The butterfly valve symbol used in process and instrumentation diagrams (P&ID) is a circle intersected by a straight line. This symbol helps engineers quickly identify valve types during system planning and troubleshooting.

Butterfly Valve HSN Code Reference

The butterfly valve HSN code is 8481. This classification is used for GST filing, procurement processes, and international trade. It ensures proper documentation and helps businesses comply with tax regulations.

Butterfly Valve Uses Across Industries

Butterfly valve uses span across water treatment plants, HVAC systems, oil and gas refineries, chemical processing units, food & beverage production, and fire protection systems. They are ideal for systems needing quick shut-off, regulation, and compact design.

Butterfly Valve Actuator & Automation

A butterfly valve actuator automates the valve operation and can be electric, pneumatic, or hydraulic. These actuators enable remote control and are often integrated into SCADA or PLC systems. They are preferred in high-volume or hazardous environments where manual operation is impractical.

Stainless Butterfly Valve – Benefits & Applications

Stainless butterfly valves are manufactured using grades like SS304 and SS316. Their corrosion resistance makes them suitable for marine systems, pharmaceutical lines, and RO water systems. These valves maintain hygiene standards and offer long service life even in aggressive chemical flows.

Delval Butterfly Valve – Brand Insight

The Delval butterfly valve is a trusted brand in India, known for manufacturing ISI-certified valves for water, oil, and gas industries. Their products are available in both lug and flanged designs and support motorised control. Delval valves are popular among EPC contractors and municipal projects for their consistency and availability.

FAQs

Q1. What is the difference between lug and flanged butterfly valves?

Lug type allows one-side disassembly and modular installations, while flanged type provides stronger sealing for high-pressure systems.

Q2. How does a butterfly valve actuator work?

It rotates the disc via electric, pneumatic, or hydraulic motion for automated valve control without manual effort.

Q3. What materials are used in stainless butterfly valves?

Typically SS304 and SS316 stainless steel for enhanced corrosion resistance and hygiene compliance.

Q4. Where are double flanged butterfly valves used?

They are preferred in heavy-duty and large-diameter pipeline applications requiring structural rigidity.

Q5. What is the HSN code for butterfly valves?

The HSN code used for GST and tax classification is 8481.

Q6. Can Delval butterfly valves be automated?

Yes, Delval valves are available in actuator-compatible models for automation-friendly pipelines.