Brass Flange Valves: Transformer Applications, Specifications, and Comparison

Common Technical Specifications

All valves in this series share the following core parameters:

Nominal Pressure: 1.6 MPa

Working Medium: Oil, water, steam, non-corrosive liquids/gases, saturated steam

Operating Temperature: -35°C to 110°C

Flange Standard: GB/T 9113

Material: Brass/Bronze (compliant with C5 corrosion resistance requirements)

Common Sizes: DN15, DN25, DN50, DN80

1. Brass Flange Gate Valve

Core Application

Full-open/full-close isolation valve for pipelines. Not intended for flow regulation. Commonly used in transformer oil circuits, water supply systems, and steam lines.

Working Principle

The handwheel rotates to lift/lower the gate plate perpendicular to the fluid path:

Fully open: Straight-through flow with minimal resistance.

Fully closed: The gate plate forms a tight seal, blocking fluid flow.

Pros & Cons

✅ Advantages:

Extremely low flow resistance, ideal for low-pressure-loss applications.

Bi-directional sealing, allowing fluid to flow in either direction.

Straight-through flow path does not disrupt fluid direction, suitable for high-flow conditions.

❌ Disadvantages:

Long travel length, resulting in slow opening/closing.

Not suitable for frequent operation, as the gate plate is prone to wear.

Cannot be used for throttling; partial opening causes seal face erosion.

2. Brass Flange Globe Valve

Core Application

Used for both shut-off and throttling. Common in water, steam, and oil pipelines where flow control is required.

Working Principle

The handwheel drives the valve stem to move the disc up and down. Adjusting the distance between the disc and seat controls the flow area, enabling throttling or shut-off.

Pros & Cons

✅ Advantages:

Short travel length, faster operation than gate valves.

Excellent sealing performance, suitable for frequent switching.

Capable of flow regulation within a certain range.

❌ Disadvantages:

Higher flow resistance than gate valves, leading to greater energy loss.

Unidirectional flow only; installation must follow the indicated direction.

Long-term throttling causes disc/seat erosion and wear.

3. Brass Flange Ball Valve

Core Application

Fast-acting shut-off valve with limited flow regulation capability. Ideal for oil, water, and gas pipelines requiring quick operation.

Working Principle

A 90° turn of the handle rotates a ball with a central bore:

Open: The bore aligns with the flow path, allowing full flow.

Closed: The bore is perpendicular to the flow path, blocking fluid.

Pros & Cons

✅ Advantages:

90° turn operation, extremely fast opening/closing.

Minimal flow resistance, high energy efficiency.

Excellent sealing performance, suitable for frequent switching.

Compact structure and easy maintenance.

❌ Disadvantages:

Not recommended for long-term throttling, as it can damage the ball seal.

Primarily for shut-off, not precise flow control.

Higher cost than gate or globe valves in larger sizes.

4. Oil Sample Shut-off Valve

Core Application

A dedicated valve for transformer oil systems, designed for safe oil sampling and small-flow control. Installed on the tank bottom or side for leak-free sample collection.

Working Principle

A small globe valve structure with a spring-loaded plug. When sampling, the plug is pushed open to allow oil flow, while a one-way seal prevents air from entering the tank. The spring automatically resets the plug when closed.

Pros & Cons

✅ Advantages:

Compact and easy to install, purpose-built for transformer sampling.

Hermetic sealing prevents air/moisture contamination of the oil.

Simple operation with precise flow control for sampling.

Corrosion-resistant for long-term contact with transformer oil.

❌ Disadvantages:

Limited to sampling and small-flow control; not suitable for main line shut-off.

Not designed for large-diameter, high-flow applications.

Not suitable for frequent, high-flow switching operations.

Quick Comparison Table

Selection Recommendations

For simple on/off with low resistance: Choose a gate valve or ball valve.

For both shut-off and flow control: Choose a globe valve.

For transformer oil sampling only: Use a dedicated oil sample shut-off valve.

For frequent, fast operation: Prioritize a ball valve.