Every modern plumbing and water distribution system relies on valves to control the flow of water. Among these, the butterfly valve stands out for its simple design, quick operation, and cost-effectiveness. But many people still ask:
👉 What is butterfly valve function?
👉 What is a butterfly valve in plumbing, and why is it widely used?
This article provides a detailed guide to the function of butterfly valves and their applications in plumbing systems, helping engineers, buyers, and project owners make informed decisions.
A butterfly valve is a quarter-turn valve that regulates or isolates the flow of liquid. It consists of a circular disc mounted on a shaft.
When the handle or actuator turns the disc parallel to the flow, the valve is open.
When the disc rotates perpendicular to the flow, the valve is closed.
✅ Flow Control – Adjusting the volume of water passing through the pipe.
✅ Shut-Off – Completely stopping the flow when needed.
✅ Isolation – Allowing maintenance on parts of the plumbing system without shutting down the entire network.
✅ Backflow Prevention (when combined with other devices) – Helping protect systems from contamination.

The name comes from the disc shape, which looks like a butterfly’s wings as it rotates inside the pipeline.
In plumbing, a butterfly valve is used to control water distribution in pipelines for residential, commercial, and industrial projects. They are especially common in:
✅ Municipal water supply
✅ Wastewater treatment plants
✅ Building plumbing networks
✅ Irrigation systems
Provides quick shut-off during maintenance
Saves installation space compared to gate valves
Offers a cost-effective solution for large pipe diameters
Butterfly valves require less space and fewer materials compared to gate valves. This makes them ideal for tight plumbing installations.
They can be opened or closed with a 90° turn, reducing response time during maintenance or emergencies.
From clean water to wastewater and irrigation, butterfly valves handle a wide range of fluids in plumbing networks.
For large diameters, butterfly valves are cheaper and lighter than ball valves or gate valves, making them a popular choice for large plumbing projects.
Installed between two flanges
Compact and low-cost
Common in residential plumbing systems
Designed with threaded lugs for secure bolting
Allows one-side maintenance without disturbing the other side
Suitable for commercial plumbing
Strong and reliable connection
Used in municipal and industrial plumbing systems with large diameters
Easy and fast installation
Often used in building plumbing and fire protection networks

✅ Cast Iron / Ductile Iron – Cost-effective, suitable for water supply
✅ Stainless Steel – Resistant to corrosion, ideal for drinking water or aggressive media
✅ PVC / Plastic – Lightweight and cost-effective for irrigation and chemical applications
✅ Carbon Steel – Suitable for high-pressure plumbing systems
Cause: Worn sealing materials or debris in the pipe
Solution: Replace seat material (EPDM/NBR) and flush pipeline
Cause: Scale build-up or actuator misalignment
Solution: Regular cleaning and correct actuator selection
Cause: Improper material selection
Solution: Use stainless steel or epoxy-coated ductile iron
Ensure the valve matches the system requirements.
Wafer, lug, flanged, or grooved depending on the pipeline design.
Cast iron for municipal water
Stainless steel for potable water
PVC for low-cost irrigation systems
Look for ISO, EN, or AWWA certified valves for reliability.

✅ Residential plumbing systems (water distribution and shut-off)
✅ Commercial buildings (HVAC and fire protection)
✅ Irrigation projects (agricultural water supply)
✅ Industrial plumbing networks (cooling water, wastewater)
✅ Municipal water supply and treatment plants
The butterfly valve is a reliable, compact, and cost-effective solution for controlling water flow in plumbing systems. Its simple design, quick operation, and wide applicability make it one of the most popular choices in residential, commercial, and industrial water networks.
At WEIZIDOM, we manufacture high-quality butterfly valves for plumbing systems in cast iron, ductile iron, stainless steel, carbon steel, and PVC. With 100+ export markets, 1000+ projects, and 5+ factories, we are trusted worldwide for reliable water system solutions.
📧 Contact us at eileen@wsdsolution.com for free catalogs and best quotations.
🌐 Visit: www.wsdsolution.com