Butterfly Valve

Transformer Butterfly Valve

Product Introduction

[Ziyang]  |  [Shenyang, China]  |  www.ziyangelectric.com

1. Product Overview

The transformer butterfly valve is a quarter-turn on/off valve specially designed for oil-immersed power and distribution transformers. Mounted on the transformer tank, radiator, conservator and oil piping systems, it provides reliable shut-off and flow control for insulating oil with minimal pressure drop and a compact footprint.

Engineered for both manual operation and actuator automation, our butterfly valves ensure quick isolation during maintenance, preventing oil leakage and contamination. With a robust ductile iron or cast steel body, a stainless steel disc and a self-compensating seal, the valve delivers bubble-tight performance across millions of operating cycles, even under the harsh thermal and seismic conditions of utility service.

2. Key Features

• Quarter-Turn Operation: 90° open/close action enables fast isolation and is easily adaptable to electric, pneumatic or gear-actuated automation.
• Zero Leakage Sealing: An elastomeric (NBR / EPDM / VITON) seat provides bubble-tight shut-off, protecting transformer oil from moisture ingress and oxidation.
• Compact & Lightweight: Short face-to-face dimension and low weight reduce installation space and structural load on the transformer tank.
• Bi-Directional Flow: Symmetric disc design allows installation in either flow direction without compromising sealing performance.
• Corrosion & Oil Resistance: Body and disc materials are selected for long-term compatibility with transformer insulating oil and outdoor environments.
• Extended Service Life: Proven for over 10,000 cycles under rated conditions, with minimal maintenance requirements.

3. Technical Specifications

Parameter	Specification	Remarks
Nominal Diameter (DN)	50 – 400 mm	Custom sizes on request
Pressure Rating	PN 6 / PN 10 / PN 16	Class 125/150 available
Body Material	Ductile Iron / Cast Steel	Stainless steel optional
Disc Material	Stainless Steel (SS304 / SS316)	Epoxy-coated available
Seat / Seal	NBR / EPDM / VITON (FKM)	Oil-resistant grade
Stem Material	Stainless Steel (2Cr13 / SS416)	—
Connection Type	Flanged (DIN / ANSI / GB)	Wafer type optional
Operating Temperature	−20 °C to +120 °C	Seat dependent
Operating Medium	Transformer insulating oil	Mineral / synthetic
Standards	IEC 60214, GB/T 6451, DIN 3202	Third-party test on request

Note: Specifications are typical values and can be customized to match your transformer tank design and project requirements. Please send us your flange standard and dimensional drawing (DWG / DXF) for a tailored proposal.

4. Advantages vs. Gate Valve

Compared with the traditional gate valve, the butterfly valve offers significant advantages in space, weight, operation and total cost of ownership — making it the preferred choice for modern transformer auxiliary piping.

Comparison Item	Butterfly Valve	Gate Valve
Installation Space	Compact, short face-to-face	Bulky, long body
Weight	Lightweight (up to 60% lighter)	Heavy
Operation	Quarter-turn, fast open/close	Multi-turn, slow
Sealing Performance	Bubble-tight, seat self-compensating	Prone to wear over time
Maintenance	Minimal, seal replaceable	Frequent repacking
Cost (TCO)	Lower initial & lifecycle cost	Higher overall cost

5. Applications

• Oil-immersed Distribution & Power Transformers (radiator isolation, bottom oil drain)
• Oil Conservator & On-Load Tap Changer (OLTC) piping systems
• Buchholz Relay, oil level gauge and sampling point connections
• Transformer cooling (ONAN / ONAF / OFAF) oil circulation loops
• Substation & industrial power equipment oil handling systems

6. Why Choose Us

• OEM & ODM Support: Full customization of flange standard, material, seat and actuator to your drawings.
• Strict Quality Control: Every valve undergoes 100% shell pressure and seat leakage tests before shipment.
• Proven Experience: 15+ years of supplying transformer components to global markets.
• Fast Lead Time & Global Shipping: Efficient production and reliable export packaging for worldwide delivery.
• Responsive Service: Engineering support and quotation within 24 hours of inquiry.

7. Ordering Information

To help us prepare an accurate quotation, please provide the following information when sending your inquiry:

1. Nominal diameter (DN) and quantity
2. Pressure rating (PN / Class)
3. Body, disc and seat material requirements
4. Connection standard (DIN / ANSI / GB) and flange details
5. Operating temperature range and special requirements (actuator, etc.)

Send us your transformer tank drawing (DWG / DXF) for a free butterfly valve design proposal within 24 hours.