What Are the Advantages and Disadvantages of Globe Valves Compared to Ball Valves?
Globe valves and ball valves are two commonly used types of sanitary valves, with significant differences in structure and function. The advantages and disadvantages are compared as follows.
1. Advantages and Disadvantages of Globe Valves
Advantages
High precision flow regulation
The valve disc rises and falls along the axial direction, and flow control is achieved by changing the gap between the valve disc and the valve seat. The adjustment accuracy can reach ± 1%, which is suitable for precise control scenarios such as laboratory micro liquid addition and pharmaceutical filling machines.
Example: In injection production, globe valves can accurately control the filling volume of each ampoule bottle.
Excellent sealing performance
The design of soft seals (such as PTFE, rubber) can achieve zero leakage, which is especially suitable for high-purity media (such as WFI injection water) or vacuum systems, to prevent external contamination from entering.
Comparison: Under the same operating conditions, the sealing performance of globe valves is better than that of ball valves ( the sealing of ball valves depends on the fit between the ball and the sealing ring, and there may be slight gaps).
Compact structures
The valve body has a small volume and occupies less space, and is commonly used for small diameter pipelines ranging from DN15 to DN50 (such as laboratory pipelines and instrument sampling pipelines).
Advantages of hygiene design
Direct or straight flow channels (angle 45 degrees to 60 degrees) reduce medium retention, facilitate CIP cleaning, and meet the requirements of hygiene standards such as ASME BPE for "no dead corners".
Disadvantages
High flow resistance, not suitable for high flow rates
The flow channel is in an "S" shape, and the medium needs to pass through at a right angle. The pressure loss is about three to five times that of a ball valve, and the energy consumption significantly increases in scenarios with large pipe diameters (DN>80).
Application limitations: it is not suitable for main material conveying pipelines in food factories (such as tomato sauce production lines).
Slow opening and closing speed, not suitable for high-frequency operation
The valve disc needs to be fully raised and lowered along the axial direction (with a long stroke), and manual opening and closing requires multiple rotations. The response time of pneumatic/electric actuators is greater than 2 seconds, which is not suitable for scenarios such as CIP cleaning circuits that require quick switching.
Easy to clog, not suitable for media containing particles
The narrow valve seat gap is prone to getting stuck by fibers and particles (such as meat residue), causing the valve disc to be unable to fully close and requiring frequent disassembly and cleaning.
High cost (large caliber scenario)
Under the same caliber, the manufacturing cost of globe valves is higher than that of ball valves (especially when DN ≥ 100), and the actuator torque requirement is greater, resulting in an overall increase in cost.
2. Advantages and Disadvantages of Ball Valves
Advantages
Quick opening and closing, suitable for high-frequency operation
The valve core can be turned on and off by rotating 90 degrees, and manual operation only requires 1/4 turn. The response time of the pneumatic actuator is less than 1 second, making it suitable for high-frequency scenarios such as CIP cleaning and sterilization kettle quick opening.
Applications: cleaning pipelines in food factories (opened and closed dozens of times a day).
Low flow resistance and strong flow capacity
The full diameter flow channel (with a pipe diameter consistent with the valve core hole) has almost no reduction in diameter, and the pressure loss is only 1/5 of that of the globe valve, making it suitable for high flow or granular media (such as juice and sauce).
Data comparison: the flow capacity of DN100 ball valves is more than three times that of globe valves of the same diameter.
Strong anti-blocking ability
The straight through flow channel has no shrinkage or dead corners, allowing particles and fibers to pass smoothly without getting stuck, making it suitable for scenarios such as sewage treatment and beverage mixing.
Cost advantage
The structure is simple, and the manufacturing cost of large-diameter valves (DN ≥ 150) is lower than that of globe valves and butterfly valves. It is also easy to maintain (replacing the sealing ring does not require dismantling the pipeline).
Disadvantages
Poor flow regulation capability
It is only suitable for fully open or fully closed. When adjusting, the valve core is in a semi-open state, which can easily cause the medium to flush the sealing ring, resulting in wear and leakage, and the adjustment accuracy is low (error>5%).
Restricted scenario: it is not suitable for feeding control of fermentation tanks that require continuous flow regulation.
Sealing depends on the lifespan of the sealing ring.
Soft seals (such as PTFE) are prone to wear and tear under high-frequency opening and closing, with a lifespan of about 50,000 to 100,000 times, and need to be replaced regularly. Although metal hard seals are durable, they may become stuck due to thermal expansion at high temperatures.
Large volume
For ball valves with a diameter of DN50 or less, the length of the valve body is longer than that of globe valves, which takes up more space and may affect the layout of laboratory pipelines.
Restricted high temperature and high pressure
Soft sealed ball valves typically have a temperature resistance of less than 150 ℃ (EPDM), and the sealing ring is prone to deformation under high pressure (more than 2.5MPa), requiring the use of metal hard seals, but the cost significantly increases.
3. Selection Decision Suggestions
Prioritize the scenario of selecting a shut-off valve
Accurate adjustment of flow rate is required (such as control of chromatographic column eluent).
The medium is a high-purity and low viscosity liquid (such as injection water, eye drops) with a diameter of less than DN50.
The system requires zero leakage (such as vacuum distillation equipment).
Prioritize the scene of selecting ball valves
Need for quick switching or high-frequency operation (such as cleaning pipelines that can be opened and closed more than ten times a day).
The medium contains particles, fibers, or high viscosity (if juice or syrup), and the pipe diameter is more than DN50.
The budget is limited and there is no need for regulating functions (such as tank emptying valves).
Notes for special working conditions
High temperature steam: metal hard seals (such as 316L stainless steel butt welding seals) are selected for ball valves, and high-temperature resistant PTFE (resistant to 200 ℃) is selected for globe valves.
Strong corrosive medium: Both require 316L stainless steel and fluoroplastic sealing, but the sealing structure of the globe valve is better (diaphragm valves may be a better solution).
Summary
The core of the selection of globe valves and ball valves lies in the balance between functional requirements and medium characteristics.
Prioritize globe valves for control and ball valves for efficiency.
In hygiene level, ball valves must meet the requirements of surface polishing (Ra ≤ 0.8 μ m), no dead corners design, and pass certifications such as 3-A and ASME BPE to ensure compliance with food and drug production regulations.
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