Transformer Valves: Premium Fluid Control Components for Power Transformers
At Hangzhou Weshare Imp. & Exp. Co., Ltd., we design and manufacture a comprehensive range oftransformer valves (including oil drain gate valves, filling valves, sampling valves, and pressure relief valves) engineered to ensure the safety, efficiency, and reliability of oil-immersed power transformers. These critical components manage the flow of insulating oil, enable maintenance operations, and protect the transformer from overpressure or contamination. All valves adopt high-strength raw materials, precision machining and strict pressure leakage test, featuring zero leakage, oil corrosion resistance, easy installation and long service life, suitable for global power engineering and transformer supporting OEM & wholesale.
Main Types & Core Functions
Our transformer valve portfolio covers every essential fluid control need for power transformers, widely applied in oil-immersed distribution transformers, power transformers and substation equipment:
|
Valve Type |
Primary Functions |
|
Oil Drain Gate Valves |
• Controlled oil filling, draining, and sampling• Bubble-tight shut-off to prevent leaks• Suitable for routine maintenance, oil changing and emergency oil discharge |
|
Filling & Vent Valves |
• Safe top-up of insulating oil during production or service• Release of trapped air during filling to eliminate bubbles• Prevent moisture ingress into the transformer tank |
|
Pressure Relief Valves |
• Automatically vent excess pressure during internal faults (e.g., arcing)• Protect the transformer tank from rupture and catastrophic failure |
|
Sampling Valves |
• Contamination-free, drip-free oil extraction for DGA, moisture, and dielectric testing• Prevent air or moisture from entering the system during sampling |
Product Application Cases
Our transformer valves have been widely applied in global power projects, covering power grids, industrial plants, renewable energy stations and other scenarios, with proven reliability and performance. Below are typical application cases:
Case 1: Urban Power Grid Substation (Europe) - We supplied 500+ DN25 oil drain gate valves and sampling valves for a 110kV urban substation renovation project. The valves are used for routine oil change and monthly oil sampling of distribution transformers. Thanks to the bubble-tight sealing design, there was zero oil leakage during 2 years of operation, effectively reducing maintenance costs and ensuring stable power supply to 200,000+ residents.
Case 2: Industrial Transformer Supporting (Southeast Asia) - Cooperated with a leading transformer manufacturer to provide OEM oil filling & vent valves and pressure relief valves for 1000+ 35kV power transformers. The valves are customized with flange connections to match the customer's transformer tank design, and the pressure relief valves successfully prevented tank rupture during 3 internal overpressure incidents, protecting equipment and avoiding production downtime.
Case 3: Wind Power Station (North America) - Provided DN32 stainless steel sampling valves and oil drain valves for 200+ wind power transformers in an onshore wind farm. The valves are treated with special anti-corrosion coating to withstand harsh outdoor environments (low temperature -30°C, high humidity), and the drip-free sampling design ensures accurate DGA testing, helping the wind farm maintain 99.8% transformer operation efficiency.
Case 4: Industrial Plant Power Supply (Middle East) - Supplied 300+ DN20 brass oil drain valves for a petrochemical plant's power distribution system. The valves are resistant to high temperature and transformer oil corrosion, adapting to the plant's high-temperature working environment, and have been in stable operation for 3 years without maintenance, meeting the plant's strict safety and reliability requirements.
Material & Craftsmanship
1. Raw Material Selection
We use only high-grade, oil-compatible materials to ensure long-term performance, with full chemical composition testing to eliminate impurities that could degrade performance:
Valve body: Cast brass, ductile iron, or carbon steel (customizable for corrosion resistance and strength)
Sealing part: Oil-resistant PTFE, fluorine rubber, or fluorocarbon elastomers (compatible with mineral and synthetic transformer oils)
Stem & core: Stainless steel, anti-rust, anti-corrosion and wear-resistant
2. Precision Processing
Adopt CNC precision machining for all critical surfaces (valve seats, stem threads, flange faces) to tight tolerances. Sealing surfaces are mirror lapped to achieve bubble-tight shut-off even at low pressures. Threads and connections are manufactured to ISO, DIN, or ANSI standards for universal compatibility with transformer tank installation interfaces.
3. Strict Pressure & Quality Test
100% factory tested to ensure reliability:
Hydrostatic Pressure Test: Tested at 1.5× the rated working pressure to verify structural integrity.
Leakage Test: Helium or air bubble tests confirm tight shut-off and prevent moisture ingress.
Material & Performance Validation: Full chemical composition and functional testing ensure compliance with electrical industry standards.
4. Surface Treatment
Steel and iron valves are coated with oil-resistant epoxy paint to prevent rust, while brass valves are passivated for enhanced corrosion resistance. All valves are fully degreased and cleaned to eliminate manufacturing contaminants that could degrade transformer oil quality, suitable for indoor and outdoor harsh environments.
Packaging & Transportation
To ensure your valves arrive in perfect condition and comply with export requirements:
Individual Protection: Each valve is wrapped with anti-corrosion film, with plastic protective caps for ports to keep clean and dust-free.
Secure Outer Packaging: Packed by export carton + foam or solid wooden case, anti-shock and anti-collision; bulk orders are palletized for easy loading and unloading.
Documentation: Complete export documents (commercial invoices, packing lists, test certificates, and material traceability reports) provided for seamless customs clearance.
Flexible Shipping: Support sea freight, air freight and land transport; flexible lead times to meet your project schedules.
Product Advantages
✅ Zero leakage sealing performance, no oil loss and no moisture ingress
✅ Excellent resistance to transformer oil corrosion and aging, durable for long-term use
✅ High mechanical strength, suitable for indoor and outdoor substation use
✅ Simple structure, easy to install, operate and maintain, even in confined substation environments
✅ Standard size DN15 / DN20 / DN25 / DN32 / DN50, support custom size and pressure rating
✅ OEM logo, custom drawing and special specifications acceptable
✅ Strict quality inspection, stable quality for long-term batch supply, compliant with IEC, GB and customer-specific requirements
Frequently Asked Questions (FAQ)
Q1: What sizes of transformer valves do you have?
A: Standard size DN15, DN20, DN25, DN32, DN50. Custom dimension, thread type and larger sizes are available upon request.
Q2: Are the valves leak-proof?
A: All products pass 100% air tightness and hydrostatic pressure test, ensuring zero leakage in long-term operation.
Q3: Can the oil drain valves be used for both filling and sampling?
A: Yes. The dedicated sampling valve adopts sealed drip-free design, no contamination to transformer insulating oil; oil drain valves also allow controlled flow during filling and draining, with drip-free spout for clean sampling.
Q4: Do you accept OEM and customized design?
A: We support OEM logo, custom connection mode, pressure grade, special material and valve designs according to your drawings or specifications.
Q5: What is your delivery time?
A: Regular stock order 7–15 days; bulk customized order 15–25 days. Expedited shipping is available for urgent orders.
Q6: Are these valves compatible with all types of transformer oil?
A: Yes. Our seals and materials are tested for compatibility with mineral oil, synthetic ester oil, and silicone oil used in modern transformers. Custom material options are available for specialized oil types.
Q7: What is the typical pressure rating for your valves?
A: Standard valves are rated for working pressures up to 1.6 MPa (PN16), suitable for most distribution and power transformers. High-pressure versions (up to PN25 or PN40) are available upon request.
Why Choose Weshare as Your Transformer Valve Supplier?
As a trusted exporter of power transformer components,Hangzhou Weshare Imp. & Exp. Co., Ltd. delivers more than just products-we deliver reliability and peace of mind:
Decades of experience serving the global power industry
Competitive pricing with no hidden costs
Fast lead times and responsive customer support
End-to-end technical assistance from material selection to post-delivery support
OEM/ODM customization to match your exact project or brand needs
📧 Contact our engineering team today to discuss your transformer valve requirements and receive a customized quotation tailored to your project needs.