Globe valve

What Is a Globe Valve?

A globe valve is a type of valve with a rounded, globe-shaped body. It is used to open, close, or regulate fluid flow in piping systems.

Unlike ball valves or gate valves, which are designed mainly for fully open or fully closed operation, globe valves allow flow to be adjusted at multiple levels. This is achieved by the valve disc moving perpendicular to the flow direction, pressing against or lifting away from the sealing surface. Thanks to this feature, globe valves are the preferred choice for systems requiring precise flow control, such as steam, compressed air, water, oil, and chemical applications.

Globe Valve Structure

A standard globe valve consists of the following main components:

Valve body: Made of cast iron, steel, stainless steel, brass, or plastic, depending on the operating environment.
Bonnet: Covers and protects the internal moving parts, bolted to the valve body.
Stem: Transmits motion from the handwheel or actuator to the valve disc.
Disc: Directly contacts the fluid and is responsible for opening, closing, and flow regulation.
Sealing gasket: Ensures leak-free operation during use.
Handwheel or actuator: Can be operated manually, electrically, or pneumatically.

Operating Principle of a Globe Valve

A globe valve operates by adjusting the position of the valve disc relative to the valve seat inside the valve body.

Closing the valve: Turn the handwheel clockwise. This motion is transmitted to the valve stem, which moves downward. The stem pushes the valve disc tightly against the seat, completely sealing the flow passage.
Opening the valve: Turn the handwheel counterclockwise. The stem moves upward, lifting the valve disc away from the seat, allowing fluid to flow.

Basic Specifications of Globe Valves

Size: DN15 – DN1000
Body Material: Cast iron, steel, stainless steel, brass, plastic
Stem Material: Stainless steel
Disc Material: Stainless steel
Pressure Rating: PN10, PN16, PN25, PN40
Operating Temperature: –5°C to 400°C
Connection Type: Flanged, threaded
Standards: DIN, BS, JIS, ANSI
Applications: Water, oil, gas, steam, chemicals
Origin: Taiwan, China, South Korea, Japan, Germany, Italy

Common Types of Globe Valves
Classification by Material

Phân loại van cầu — **Globe Valve Classification by Material**

**Cast Iron Globe Valve:** Cost-effective, suitable for clean water systems, fire protection (PCCC), and medium-pressure steam.

**Brass Globe Valve:** Compact size, commonly used in residential water and compressed air systems.

**Stainless Steel Globe Valve:** Corrosion-resistant and heat-tolerant, ideal for chemical, food, and pharmaceutical applications. Stainless steel 304 is the most popular type due to its versatility and durability.

**Plastic / PVC Globe Valve:** Lightweight and corrosion-resistant, commonly used in wastewater treatment and low-concentration acid/alkaline solutions.

Classification by Valve Body Design

Classification by Actuation Method

Classification by Connection Type

Practical Applications of Globe Valves

Globe valves are widely used across various industries due to their excellent flow control and versatility.

Applications of Globe Valves

Water Industry: Installed in municipal water supply and drainage systems, buildings, and water treatment plants to regulate flow.
Steam and Thermal Power: Used in boilers, thermal power plants, textile, dyeing, and paper mills to control high-pressure steam.
Oil, Gas, and Chemicals: Regulates the flow of hazardous or flammable liquids, gases, or steam.
Food and Pharmaceutical: Ensures safety and precise control in production lines, especially in high-cleanliness environments.
Fire Protection (PCCC) and HVAC: Used in fire protection systems, air conditioning, and building utility pipelines.

Proper Installation of Globe Valves

Preparation Before Installation:

Check the valve: Ensure correct size (DN), material, and pressure rating according to system requirements.
Clean the pipeline: Remove rust, debris, and foreign objects to maintain valve sealing.
Determine installation position: Choose an accessible location for operation and maintenance, and ensure the arrow on the valve body aligns with the flow direction.

Installation Steps:

Place the valve in the correct position and align flanges (or threads/welds) with the pipeline.
Flanged valve: Insert the gasket between flanges and tighten bolts in a cross pattern for even pressure and leak prevention.
Threaded valve: Apply PTFE tape or sealing compound, then tighten the threads carefully to avoid damage.
Welded valve: Perform secure welding following safety standards.
Perform a final check of all connections before commissioning.

Operating Precautions:

Avoid rapid operation to prevent water hammer or pressure shock.
Do not leave the valve partially open for extended periods, as it may cause disc wear.
Follow the maximum pressure and temperature limits recommended by the manufacturer.
For pneumatic or electric actuated valves, ensure stable and correct power supply (air or electricity).

Globe Valve Maintenance

Bảo trì van cầu — **Periodic Maintenance of Globe Valves**

**Regular Inspection:**

Check the valve body, flanges, and threads for leaks.

Test sealing when the valve is fully closed.

For high-temperature steam valves, regularly inspect the heat resistance to prevent cracking.

**Cleaning:**

Remove dirt and deposits from the valve exterior.

Disassemble the valve disc and gasket for cleaning if the flow is obstructed or the operation is not smooth.

Avoid using strong chemicals on plastic or stainless steel valves to prevent corrosion.

**Lubrication:**

Periodically lubricate the valve stem to reduce friction and prevent sticking.

Use grease suitable for the environment (water-resistant, heat-resistant).

**Replacing Worn Components:**

Replace gaskets if hardened, worn, or cracked.

Replace the valve disc if the contact surface is scratched or no longer seals properly.

For pneumatic or electric actuated valves, inspect and replace actuators if performance decreases.

Where to Buy High-Quality Globe Valves at a Good Price

When purchasing globe valves, the most important factors are product quality, clear origin, and reliable support. While there are many suppliers on the market, not all guarantee genuine products with full quality certificates and warranties.