💧 Double-Eccentric Extended-Stroke Butterfly Valve

38 years of valve manufacturing experience | Specializing in water treatment | Large-diameter water supply and drainage pipeline solutions

What if valves are installed underground, in deep wells, on pipe racks, or in areas with limited on-site operating space?

Standard butterfly valves may be out of reach, difficult to operate, and even constrained by pipe insulation and the installation environment.

Double-Eccentric Extended-Stroke Butterfly Valve Building on the double-eccentric butterfly valve, the stem is lengthened to extend the operating position to a more convenient location.

While retaining the double-eccentric butterfly valve Low opening and closing torque, reliable sealing, and smooth operation. and other features, while also addressing operational challenges in specialized installation environments.

💧 Double-eccentric structure
📏 Extended rod design
🛡️ Soft-seal structure
🔩 Flange connection optional
⚙️ Various drive modes, including manual and electric.

🔧 I. Double-eccentric design to reduce seal wear

The core advantage of a double-eccentric butterfly valve is that it enables the disc to disengage from the sealing surfaces more quickly during opening.

Compared with conventional concentric butterfly valves, it can effectively reduce friction between the valve disc and the sealing ring.

✔ Reduces seal wear
✔ Reduces opening and closing torque
✔ Enables smoother operation
✔ Reduce seal damage
✔ Extend valve service life

For Large-diameter water supply, sewage, and water treatment pipelines In this regard, the double-eccentric design can simultaneously optimize sealing performance and operational efficiency.

💡 Simply put:

It reduces friction when opening and ensures a tight seal when closing.

📏 II. Extended rod design, addressing special installation environments

Valves are not always installed in easily accessible locations.

For example:

⬇️ Underground Valve Chamber
⬇️ Deep-buried pipeline
⬇️ Underground Utility Tunnel
⬇️ High-level pipeline
⬇️ Insulated piping
⬇️ Area with restricted operating space

A standard valve stem may not meet the operational requirements on site.

The extension rod can be adjusted to extend the operating position to a more convenient height, depending on the actual installation requirements.

👉 The valve is installed too deeply, making it impossible to operate comfortably.

The length of the extension rod can be adjusted according to:

📐 Pipe center height
📐 Valve well depth
📐 Insulation layer thickness
📐 On-site operating height
📐 Actuator installation location

Conduct reasonable design.

🛡️ 3. Soft-seal design, suitable for water treatment applications.

One of the most fundamental requirements for butterfly valves in water treatment systems is:

Reliable shut-off, reduced leakage.

The double-eccentric soft-seal butterfly valve employs an elastic sealing structure, delivering excellent sealing performance under applicable operating conditions.

Common sealing materials include:

🔹 EPDM
🔹 NBR
🔹 PTFE
🔹 FKM (Fluororubber)

Different media, temperatures, and pressures require corresponding sealing materials.

📌 If you’re unsure which sealing material to choose, there’s no need to decide on your own.

To put:

Medium + Temperature + Pressure

Send it to us, and we’ll help you confirm.

💧 IV. Specifically designed for water supply, drainage, and water treatment systems

Double-eccentric extended‑stem butterfly valves are particularly well suited for water‑system piping.

Common applications:

💧 Municipal Water Supply
💧 Wastewater treatment
💧 Water Plant
💧 Raw Water输送
💧 Pumping Station
💧 Reservoir water conveyance
💧 Water Conservancy Project
💧 Industrial Circulating Water
💧 Underground Utility Tunnel

For large-diameter water pipelines, butterfly valves feature a compact structure, relatively light weight, and convenient opening and closing.

🔩 V. Suitable for Large-Diameter Pipelines

As the pipe diameter increases, the valve’s weight, installation space requirements, and on-site operational complexity all increase.

Double-eccentric butterfly valves are particularly suitable for:

DN200, DN300, DN500, DN800, DN1000… and even larger diameters.

Different options can be provided according to project requirements:

✔ Nominal diameter
✔ Nominal pressure
✔ Flange Standard
✔ Valve body material
✔ Valve Disc Material
✔ Sealing material
✔ Valve stem length
✔ Drive Type

📌 Large diameter + deep‑buried installation + inconvenient operation

This is precisely the most common application scenario for extended‑stem butterfly valves.

⚙️ 6. Manual, electric, and multiple drive options

Based on on-site operational and automated control requirements, the following can be configured:

🔘 Manual
🔘 Worm gear and worm shaft
🔘 Electric
🔘 Pneumatic

If remote control is required, it can also be configured according to the project’s specifications:

✔ Switch control
✔ Adjustment Control
✔ Switch position signal feedback
✔ Remote Control Accessories

Enable better integration between the valve and the entire water treatment control system.

📐 VII. Product Specifications

📌 Specific specifications, pressure ratings, materials, sealing solutions, extension rod lengths, and drive configurations can be customized to meet project requirements.

🏗️ 8. A longer extension pole isn’t necessarily better.

This is an issue that many customers tend to overlook.

The length of the extension rod shall be determined in accordance with the actual on-site installation conditions.

If the rod is too short:

❌ The operating position is inconvenient.

If the rod is too long:

❌ Increased costs
❌ Takes up more space
❌ May affect on-site installation

Therefore, we recommend:

Determine the length of the extension rod based on the on-site dimensions.

If you have the site drawings, piping layout diagrams, or installation dimensions on hand, simply send them to us.

We can help you confirm the appropriate extension rod solution.

🏆 9. 38 years of valve manufacturing experience, specializing in water treatment.

Zhengzhou Zhongnan Valves was founded in 1988 。

For the past 38 years, we have been dedicated to valve manufacturing, with a particular focus on serving:

💧 Water Supply and Drainage Engineering
💧 Water Treatment Project
💧 Municipal Water Supply
💧 Wastewater treatment
💧 Water Conservancy Project
💧 Pumping Station
💧 Industrial Water Systems

The main products include:

🔹 Double-eccentric butterfly valve
🔹 Double-Eccentric Extended-Stroke Butterfly Valve
🔹 Triple-eccentric butterfly valve
🔹 Seawater butterfly valve
🔹 Eccentric Hemisphere Valve
🔹 Rotary ball valve
🔹 Flow and pressure regulating valve
🔹 Hydraulic Check Valve

For 38 years, we’ve not only been manufacturing valves—we also deeply understand water‑treatment operating conditions.

From standard plumbing and drainage systems to large-diameter, deeply buried pipelines in specialized installation environments, our primary focus is:

What kind of valve design is truly suited to your site?

💬 10. Looking for a double-eccentric extended-stem butterfly valve?

You don’t need to identify the model first.

Simply send us the information below:

📌 Caliber: DN?
📌 Pressure: PN / Class?
📌 Medium: Water / Wastewater / Seawater / Other?
📌 Work stress: How much?
📌 Temperature: How many °C?
📌 Installation depth: How much?
📌 Extension rod length: Are there any requirements?
📌 Drive type: manual / electric?
📌 Quantity: How many units?

📩 It’s okay even if you don’t have all the parameters.

You can just send it directly:

① Valve List
② Project Drawings
③ Technical Specification Document
④ On-site photos

We have confirmed for you based on the available information:

✔ Valve Model
✔ Caliber and Pressure Rating
✔ Sealing material
✔ Valve body and valve disc materials
✔ Extension rod length
✔ Drive Type
✔ Project Quotation Proposal

💧 Deeply buried pipelines—hard to access?

📏 Need an extension rod, but unsure how long to make it?

Please send us the on-site dimensions, and we’ll help you confirm them together.

38 years of valve manufacturing experience · Specializing in water treatment · Specializing in eccentric valves

👉 Send the DN, PN, medium, and installation dimensions, and we’ll help you with the selection first.