Wafer Vs. Double Flanged Butterfly Valves: Which One Should You Choose?

Introduction

When specifying a butterfly valve, the first decision is often the connection type. Two of the most common options are the wafer type and the double flanged type.

While they may look similar internally—both use a rotating disc to control flow—their external designs dictate how they mount to the pipeline, how much space they require, and how easy they are to maintain. Choosing the wrong one can lead to installation headaches, higher costs, or unnecessary downtime.

This guide breaks down the differences between wafer and double flanged butterfly valves, helping you select the right configuration for your system.

What is a Wafer Butterfly Valve?

A wafer butterfly valve is designed to be sandwiched between two pipe flanges. It does not have its own flanges. Instead, long through-bolts pass through both pipe flanges and the valve body to secure it in place.

Advantages of Wafer Valves:

• Compact and Lightweight: Because there are no integral flanges, the face-to-face dimension is very short. It takes up minimal space in tight piping layouts.

• Cost-Effective: Less material is used in the body casting, making wafer valves the most economical choice.

• Easy to Install (with proper alignment): Once the flanges are aligned, it simply slides between them.

 

Limitations of Wafer Valves:

• No Dead-End Service: A wafer valve relies on both flanges for support. If you remove the downstream pipe, the valve cannot hold the pressure and will not seal.

• Difficult Maintenance: To remove a wafer valve, you must disconnect both sides of the pipeline and spread the flanges apart.

 

What is a Double Flanged Butterfly Valve?

A double flanged butterfly valve has its own integral flanges (typically drilled to match ANSI, DIN, or JIS standards) on both ends. It bolts directly to the mating pipe flanges.

Advantages of Double Flanged Valves:

• Self-Supporting and Rigid: The integral flanges provide structural strength. The valve can independently carry pipe loads, making it ideal for large-diameter pipelines or systems with heavy vibration.

• Bidirectional Dead-End Service: You can isolate and remove the downstream pipe while the valve remains under pressure and fully sealed.

• Easier Maintenance: Because it connects directly to the flanges, you can unbolt just one side to perform maintenance without disrupting the other side of the pipeline.

• Suitable for Large Sizes and High Pressure: The robust design is standard for large diameters (e.g., above DN600) and higher pressure ratings.

 

Limitations of Double Flanged Valves:

• Heavier and More Expensive: More metal is required for the body and flanges, increasing both weight and cost.

• Requires More Space: The face-to-face length is longer than a wafer valve, requiring more room in the piping layout.

 

The "In-Between" Option: Lug Butterfly Valve

 

It is worth mentioning the lug-style butterfly valve, which bridges the gap between wafer and double flanged. A lug valve has threaded inserts on the body, allowing it to be bolted independently to each pipe flange.

It offers the dead-end service and independent maintenance of a flanged valve, but with a more compact, wafer-like body.

However, it still relies on the pipe flanges for support, unlike a fully self-supporting double flanged valve.

 

Beyond Connection: Don't Forget the Seat Material

Once you have decided between wafer, lug, or flanged, the next critical choice is the seat material.

• Resilient Seats (EPDM, NBR): The standard choice for water and wastewater. They offer excellent sealing but are limited by temperature and chemical compatibility.

• PTFE Seats: If your media contains strong acids, solvents, or operates at higher temperatures, a PTFE seat or a fully PTFE-lined valve is often required to prevent corrosion and ensure long-term reliability.

 

Which One Should You Choose?

Here is a quick selection guide based on common application needs:

 

How Tianjin Worlds Valve Can Help

At Tianjin Worlds Valve Co., Ltd., we manufacture the complete range: wafer, lug, and double flanged butterfly valves. Whether you need an economical wafer valve for a water line or a heavy-duty flanged valve with a PTFE lining for chemical service, we can build it to your specifications.

As an OEM/ODM manufacturer with over 19 years of export experience, we hold CE/PED (Module H) and UKCA certifications for pressure equipment safety, as well as WRAS and ACS approvals for potable water applications. Every valve is 100% pressure tested before shipment.

If you are unsure which configuration is best for your project, tell us your pipe size, media, pressure, and space limitations. Our engineering team will recommend the right valve for your system.

Contact us with your requirements, and we will respond within 24 hours.