What is a PVC Butterfly Valve? Structure, Applications & 2025 Quotation

 

PVC butterfly valves are increasingly becoming a popular choice in water, chemical, and wastewater treatment systems due to their compact design, superior corrosion resistance, and reasonable cost. Unlike heavy metal valves, PVC plastic valves are lightweight, easy to install, and still ensure reliable flow control performance.

This type of valve is particularly suitable for highly corrosive environments such as acids, bases, or salt water – where conventional materials are prone to damage. However, to choose the right valve, you need to understand its structure, operating principle, advantages and disadvantages, and also the cost according to different sizes and control types.

In this article, Bao Tin Steel will help you compile all comprehensive information about PVC butterfly valves: from classification, applications, the latest 2025 price list, to installation methods and most effective maintenance.

What is a PVC Butterfly Valve?

A PVC butterfly valve is a type of industrial butterfly valve used to start, stop, or regulate the flow of liquid in piping systems. Unlike traditional valves made from cast iron or stainless steel, this valve is manufactured from Polyvinyl Chloride (PVC) plastic material—known for its excellent chemical corrosion resistance, lightweight nature, and affordable cost.

Regarding its structure, a PVC butterfly valve features a circular disc (valve disc) positioned inside the valve body, rotating around a central shaft. When the disc rotates parallel to the flow, the valve is fully open; when it rotates perpendicular, the flow is blocked. With a 90-degree rotational design, opening and closing operations are very fast and flexible, saving space and making maintenance convenient.

With its simple yet effective structure, PVC butterfly valves are commonly used in water treatment, swimming pools, chemical systems, aquaculture, and the food industry. Notably, this type of valve is ideal for corrosive environments, where metal valves tend to degrade over time.

Structure and Operating Principle

Despite their compact design, PVC butterfly valves possess a highly efficient structure, making them suitable for both residential and industrial systems.

Basic Structure

The structure consists of 5 main components:

• Valve body: This is the outer casing, made from PVC, uPVC, cPVC, or PVDF, designed to withstand pressure and corrosion.
• Valve disc: A circular, butterfly-shaped disc that rotates to regulate fluid flow. It can be rubber-lined to prevent leakage.
• Valve stem: Connects the valve disc to the control mechanism, typically made from stainless steel 304/316 for corrosion resistance.
• Sealing gasket: Made from EPDM, PTFE, FPM, etc., ensuring a complete and leak-proof seal.
• Control mechanism: A lever handle, handwheel, or electric/pneumatic actuator – enabling quick opening and closing.

Important Note: The gasket is a critical component that must be chosen with the correct material based on the chemical environment (acids, bases, chlorine, etc.) to ensure maximum valve lifespan and sealing integrity.

Operating Principle

The valve operates by rotating the valve disc 90 degrees around its axis:

• When the disc rotates parallel to the flow, the valve is fully open, allowing fluid to pass through easily.
• When the disc rotates perpendicular to the flow, the valve closes, blocking the fluid flow.
• An intermediate rotation angle puts the valve in a partially open state, allowing for flexible flow regulation.

With its simple yet effective principle, PVC butterfly valves help reduce pressure drop, minimise flow friction, and save significantly more energy compared to other valve types like globe valves or gate valves.

Classification of PVC Butterfly Valves

To select the correct PVC butterfly valve for your system, you need to understand the classification criteria. In practice, this type of valve is divided into various forms depending on its control mechanism, material composition, and connection type to the pipeline.

Classification by Control Mechanism

Classification by Control Mechanism

Lever Handle Butterfly Valve

• Controlled by a simple lever handle with a 90° opening angle.
• Suitable for small systems, offering quick opening/closing and easy operation.
• Common sizes: DN50 – DN200.
• Lowest cost among all types.

Handwheel (Gear) Butterfly Valve

• Uses a handwheel + gearbox to open slowly.
• Requires less effort when used with larger valves.
• Typically applied to medium to large pipelines (DN100 – DN600).
• Slightly higher cost than lever handle types.

Pneumatic Actuated Butterfly Valve

• Opens/closes the valve using compressed air pressure.
• Very fast opening/closing speed (~1–2 seconds).
• Suitable for hazardous environments and where high automation is required.
• Mid-range price, cheaper than electric actuated valves.

Electric Actuated Butterfly Valve

• An electric motor controls the valve’s opening and closing.
• Can be integrated with remote control and PLC systems.
• Easily connects to industrial automation systems.
• Highest cost but offers excellent and highly accurate control.

Classification by Valve Body Material

Type of Plastic	Key Characteristics	Typical Applications
PVC	Good chemical resistance, low cost, temperature limit ~55–80°C	Water treatment, residential systems
uPVC	Rigid unplasticized PVC, twice the pressure resistance of PVC	Light industry, medium-pressure chemical applications
cPVC	Higher heat resistance (~90–110°C), better acid/base resistance than PVC/uPVC	Chemical industry, hot water, engineering systems
PVDF	Ultra-durable, resistant to very strong chemicals and high temperatures (~150°C)	Pharmaceutical industry, cleanrooms, concentrated acid treatment

Advantages and Disadvantages of PVC Butterfly Valves

Like any industrial equipment, PVC butterfly valves have both their strengths and limitations.

Outstanding Advantages:

• Cost-Effective: PVC butterfly valves are generally much cheaper than stainless steel, cast iron, or metal ball valves. This makes them an ideal choice for systems requiring a large quantity of valves or those with budget constraints.
• Superior Corrosion Resistance: PVC offers excellent resistance to acids, alkalis, salts, chlorine, and more, allowing the valve to operate reliably in corrosive environments where metal valves would easily degrade.
• Lightweight: Compared to metal valves of the same size, plastic valves are significantly lighter. This eliminates the need for complex pipeline structural reinforcement or heavy lifting equipment.
• Simple Operation and Maintenance: They have a simple structure with fewer components, making assembly and disassembly quick. This is especially true for lever-operated valves, which can be actuated with a single, light pull.
• Enhanced Safety: The natural electrical insulating properties of PVC increase safety in areas with potential electrical leakage and provide explosion protection.
• High Aesthetics: They boast high aesthetic appeal, do not rust, and resist discolouration. This makes them particularly suitable for exposed systems, food processing plants, and domestic water treatment.

Alongside these advantages, it also has certain limitations, such as:

• Temperature and Pressure Limitations: Standard PVC valves typically only withstand temperatures around 55–80°C and pressures up to 10 bar.
• Lower Mechanical Durability: They have lower mechanical strength, are prone to fading, becoming brittle and cracking, or deforming after extended use.
• Poor Resistance to Abrasives: Plastic valves cannot tolerate high friction from sand, mud, gravel, and similar abrasive materials, which can easily scratch the valve disc and damage the sealing gasket.
• Lower Performance in Continuous Operation: Their performance in continuous opening and closing cycles is inferior to that of cast iron or stainless steel valves.

Practical Applications in Residential and Industrial Settings

With their chemical corrosion resistance, low cost, lightweight nature, and simple operation, PVC butterfly valves have become a popular choice in numerous industries and residential systems. Below are some typical applications you might encounter:

• Used in clean water treatment plants, domestic and industrial wastewater treatment.
• Water filtration systems, building water supply and drainage, storage tanks, and swimming pool water pumps.
• Installed in reaction tanks, mixing lines, plating workshops, and laboratories in the chemical and electroplating industries.
• Regulating the flow of water, milk, soft drinks, saline solutions, alcohol, etc., in the food, beverage, and pharmaceutical industries.
• Applied in drip irrigation systems, mist irrigation, and controlling water supply in shrimp and fish ponds, and artificial lakes.
• Used in flexible air ducts and factory air handling systems.
• Building fire suppression systems (clean water, not high pressure).
• Mineral processing plants, paper mills, textile dyeing factories.
• Agricultural pumping stations, new urban areas, industrial zones.

A PVC butterfly valve is an economical, efficient, and versatile solution for most mild-to-moderately corrosive fluid systems, or those with low temperature/pressure, ranging from residential to large-scale industrial applications.

Latest 2025 PVC Butterfly Valve Price List

The price of PVC butterfly valves in the market depends on various factors: size (DN), material (PVC, uPVC, cPVC), control mechanism (lever, handwheel, electric, pneumatic), as well as the brand and origin. Below is a reference price list, compiled from reputable suppliers in Vietnam, as of 2025:

Price List for Lever Handle Plastic Butterfly Valves (PVC/uPVC)

Diameter (DN)	Standard PVC Valve (VND)	uPVC Valve (VND)
DN60	360,000	–
DN76 (D75)	420,000	–
DN90	520,000	–
DN110	660,000	–
DN140	1,300,000	–
DN160	1,400,000	–
DN200	2,100,000	1,370,000

Price List for Handwheel Plastic Butterfly Valves (PVC/uPVC)

Diameter (DN)	Standard PVC Valve (VND)	uPVC Valve (VND)
DN60	1,200,000	–
DN76 (D75)	1,300,000	–
DN90	1,350,000	–
DN110	1,400,000	–
DN140	2,300,000	–
DN160	2,800,000	–
DN200	3,700,000	–
DN250	5,700,000	3,700,000
DN300	6,500,000	4,200,000

Price List for Automatic Control Plastic Butterfly Valves (PVC/uPVC)

DN	Price (VND)	Type of Control
DN50	2,000,000	Electric Actuated (uPVC)
	700,000	Pneumatic Actuated (uPVC)
DN80	3,040,000	Electric Actuated (uPVC)
	1,060,000	Pneumatic Actuated (uPVC)
DN100	2,260,000	Electric Actuated (uPVC)
	1,340,000	Pneumatic Actuated (uPVC)
DN300	15,060,000	Electric Actuated (uPVC)
	10,080,000	Pneumatic Actuated (uPVC)

Tips for Choosing the Right PVC Butterfly Valve

Selecting a PVC butterfly valve shouldn’t be based solely on price or size. Instead, it’s crucial to consider the actual operating environment: the fluid being handled, temperature, pressure, and operational needs. Choosing the wrong material or control mechanism can easily lead to leaks, valve damage, or reduced system lifespan.

Here are the criteria you should consider when making your selection:

Don’t just pick “the cheapest valve”; choose “the most suitable valve for the operating environment” to avoid maintenance and replacement costs that could be 5–10 times higher later on.

Guide to Correct Technical Installation of PVC Butterfly Valves

Proper technical installation will help PVC butterfly valves operate stably, ensure tightness, limit leakage, and extend their lifespan. Below is a step-by-step guide compiled by Thép Bảo Tín according to standard procedures:

Preparation Before Installation

Before you begin, make sure to take these preparatory steps:

• Depressurise and Drain: Ensure the pipeline is completely depressurised and all fluid has been drained.
• Clean Surfaces: Thoroughly clean the pipe and flange surfaces, removing any sand, dust, or residue.
• Check Dimensions: Verify that the distance between the two flanges perfectly matches the valve’s length.
• Gather Tools and Materials: Prepare all necessary bolts, nuts, sealing gaskets (if additional ones are being used), and tools such as wrenches, hex keys, pliers, and monkey wrenches.

Installing the Valve into the System (7 Standard Steps)

• Step 1: Position the valve between the two flanges on the pipeline. Adjust the valve disc to be 1/4 open to prevent it from rubbing against the flanges.
• Step 2: Insert two opposing bolts temporarily to hold the valve in place.
• Step 3: If flange welding is required: Remove the valve from the pipe after aligning it correctly. Then, weld the flanges securely to prevent heat damage to the valve’s gasket. Step 4: After welding is complete and the pipe has cooled, place the valve back into its original position.
• Step 5: Install all bolts, tightening them evenly in a crisscross (star) pattern. Ensure there’s no eccentricity and avoid over-tightening.
• Step 6: Test operation: Open and close the valve a few times to check for smooth operation and the tightness of the valve disc.
• Step 7: If you observe leakage or the disc rubbing, remove the valve and recheck Step 5, particularly the concentricity and bolt tightening.

Notes for Outdoor or Corrosive Environment Installation

• Outdoor installation: You should cover the valve to protect it from direct UV rays (to prevent plastic degradation).
• Avoid bending stress: Do not allow the valve to bear bending forces from the pipeline; use supports if the pipe is long.
• No adhesives or silicon: Do not use glue or silicone on the flange faces as this can jam the valve disc.

After installation is complete, you should record a technical log (installation date, installer, materials used) and perform a final check using a pressure test to ensure absolute safety before official operation.

PVC Butterfly Valve Maintenance Guide

For PVC butterfly valves to operate reliably, without leaks, jamming, or gasket failure after some time in use, regular maintenance is essential. This is especially true in environments with chemicals, dirty water, or systems that frequently open and close.

Below is a standard maintenance guide, compiled by Bao Tin Steel based on practical experience from various projects:

Step 1: Shut Down the System – Depressurise

• Completely shut off the flow and ensure there’s no pressure remaining in the pipeline.
• Remove the valve if a thorough internal inspection is needed.

Step 2: Clean the Valve (Internal & External)

• Use a clean cloth, soft brush, or air blower to remove dust, sediment, and algae.
• Do not use strong chemicals or petroleum solvents to clean plastic valves.

Step 3: Inspect the Sealing Gasket

• Visually inspect the gasket for any scratches, hardening, or cracks.
• If there are signs of degradation, replace it with a new gasket of the same material (EPDM, PTFE, Viton, etc.) that is compatible with the fluid medium.

Step 4: Check the Valve Stem and Disc

• Ensure the stem isn’t bent and the valve disc rotates smoothly without rubbing against the flange wall.
• If the valve disc is misaligned, it might be due to improper valve installation or over-tightened bolts – adjust as needed.

Step 5: Lubricate the Control Mechanism (If Applicable)

• For handwheel, pneumatic, or electric valves: apply light grease or oil to the drive shaft (if permitted by the manufacturer).
• Do not use industrial oil on parts that come into contact with the plastic gasket.

Step 6: Test Operation

• Open and close the valve at least 3 times to check for smooth operation, absence of sticking, and proper alignment.

Comparing PVC Butterfly Valves with Ball Valves

Compare with ball valve

Criteria	PVC Butterfly Valve	Ball Valve (Plastic or Stainless Steel)
Operating Principle	Rotates a circular disc 90°, located within the flow path	Rotates a hollow spherical ball inside
Main Function	Regulating & On/Off	Primarily On/Off (fully open/closed)
Throttling Capability	Good – flexible 1/4 to 3/4 turn rotation	Poor – easily causes wear on seals if used for throttling
Pressure Resistance	Low to medium (PN6–PN10)	Higher, good for PN16–PN40
Weight – Size	Light, thin, compact	Bulky, heavier
Cost	20–50% cheaper	Higher, especially if stainless steel is used

Compare with gate valve

Criteria	PVC Butterfly Valve	Cast Iron/Stainless Steel Gate Valve
Design	Thin disc rotates within the body	Wedge gate lifts/lowers vertically
Installation Space	Requires very little space	Occupies significant vertical space
Throttling Capability	Can throttle (rotate at various angles)	No throttling – only fully open/closed
Opening/Closing Speed	Very fast (90° lever operation)	Slow – requires many turns
Cost	Significantly cheaper	Often 20–40% higher

Comparison with cast iron/stainless steel butterfly valve

Criteria	PVC Butterfly Valve (PVC/uPVC/cPVC/PVDF)	Cast Iron/Stainless Steel Butterfly Valve (Ductile Iron, SS 304/316)
Material	PVC/uPVC/cPVC/PVDF	Ductile Iron, Stainless Steel 304/316
Chemical Corrosion Resistance	Excellent with acids, bases, salts	Stainless steel is good; cast iron is susceptible to corrosion in chemical environments
Temperature Resistance	55–110°C depending on plastic material	150–250°C (Stainless Steel)
Pressure Resistance	Up to PN10	PN16 – PN40 or higher
Cost	30–60% cheaper	Higher, especially for stainless steel valves
Weight	Lightweight – easy to install	Heavy – requires support systems

Bao Tin Steel – Your Trusted Supplier of Plastic Butterfly Valves

If you’re looking for a reliable supplier of PVC plastic butterfly valves with good pricing, technical support, and complete documentation, then Bao Tin Steel is a trustworthy choice.

We are not just a distributor of industrial valves; we are also a technical partner, collaborating with hundreds of clients in the fields of water treatment, chemicals, food processing, construction, and M&E (mechanical and electrical).

Why Choose Bao Tin Steel?

• Genuine Products – Clear Origin: We provide authentic products with complete CO (Certificate of Origin) and CQ (Certificate of Quality) documentation.
• Diverse Range: We offer a wide variety of butterfly valves, including lever handle, handwheel, pneumatic, and electric controlled types, ranging from DN50 to DN400. All are readily available in our warehouse for quick delivery to any project.
• Competitive Pricing: Benefit from excellent prices and high discounts for distributors and large-scale projects.
• Dedicated Technical Consultation: Our team provides heartfelt technical advice and offers nationwide delivery.

Submit your request today – We are always ready to support you 24/7!

Hotline: 0932 059 176 – Email: kinhdoanh@thepbaotin.com

Conclusion

The PVC butterfly valve is a smart choice for fluid systems with corrosive properties and moderate pressure and temperature. With outstanding advantages such as its low cost, lightweight nature, excellent chemical resistance, and ease of installation, this type of valve is widely applied in water treatment, chemical processing, food, aquaculture, and many other industries.

However, to maximise the valve’s efficiency and lifespan, you need to select the correct material, control mechanism, and reputable supplier.