Two types may seem similar in valves but have different functions – check valve and globe valve. Both regulate the flow of fluids, gases, or slurries in a pipeline but differ in structure, application, and performance. If you’re working in plumbing, petrochemical, refining, or HVAC, you might encounter these valves and need to choose the right one for your system. Therefore, it’s essential to understand the difference between a check valve and a globe valve. In this blog post, we’ll explain these two valves’ main features and uses and help you make an informed decision.
What is Check Valve?
A check valve is a backflow prevention device allowing water to flow in one direction. It helps prevent reverse flow and unplanned back-siphonage of fluids while automatically permitting forward flow. Check valves are commonly used in residential, commercial and industrial applications such as plumbing systems, HVAC systems, power-generating plants and wastewater treatment facilities.
What is Globe Valve?
Globe valves are a type of control valve used for regulating flow in a pipeline. They consist of a movable disc-like element and a stationary ring seat and work by using the motion of the disc to either open or partially block the flow. This allows them to be more precise than other valves, as they can control pressure and flow rate over varying ranges. Globe valves also have superior tight shutoff capabilities, making them well-suited for water distribution systems, petrochemical industries, turbo machinery control systems, etc.
Difference Between Check Valve and Globe Valve
Design and Function:
The most noticeable difference between check and globe valves is their structure and mechanism. A check valve has a disc or ball inside the body that allows fluid to flow in one direction (usually from inlet to outlet) and blocks it in the opposite direction, preventing backflow or reversal. It doesn’t require any external force to operate, as the fluid pressure opens or closes the valve. On the other hand, a globe valve has a cylindrical or spherical body with a plug or disc that tightens against a seat to regulate the flow. It can be moved up and down or rotated by a handwheel or a motor to open, close or adjust the valve. It’s usually used for throttling or modulating the flow rather than preventing backflow.
Application and Industry:
Another difference between check and globe valves is their typical use and industry. A check valve is commonly used in applications where backflow prevention is critical, such as water supply, sewage, fire protection, or chemical processing. It’s also suitable for systems with variable pressure or velocity, as it can adjust to the fluid’s direction and speed. In contrast, a globe valve is often used in applications requiring precise flow rate or pressure control, such as HVAC, power generation, oil and gas, or pharmaceutical manufacturing. It’s also suitable for low-temperature or high-pressure fluids, which can withstand stress and temperature variation.
Performance and Maintenance:
A check valve and globe valve also differ in performance and maintenance requirements. A check valve is generally more reliable and efficient in preventing backflow and reducing water hammer, as it doesn’t have any stem or packing that may cause leaks or friction. However, it may cause some resistance or turbulence in the flow, especially if it needs to be properly designed or sized. As for maintenance, a check valve is usually easy to install and operate, as it doesn’t require any adjustment or lubrication. However, if used in a corrosive or abrasive environment, it may need frequent cleaning or replacement. On the other hand, a globe valve requires more attention and expertise in operation and maintenance, as it has more components and may suffer from wear, erosion, or misalignment. However, it can provide accurate and consistent flow control if properly installed and calibrated.
Cost and Availability:
Last but not least, a check valve and globe valve differ in cost and availability. A check valve is generally cheaper and more widely available than a globe valve, as it has a simpler design and fewer parts. It’s also easy to replace or repair in case of failure, as it requires no special tools or skills. However, a globe valve may be more expensive and harder to find, especially if it’s made of high-grade material or customized for specific requirements. It may also require more lead time or shipping costs, as it may be imported from overseas or manufactured on demand.
In conclusion, check valves and globe valves have different structures, functions, and applications, and choosing the right one depends on your system’s specific needs and conditions. If you need to prevent backflow or reduce water hammer, a check valve may be the best choice, as it’s simple, reliable, and cost-effective. If you need to regulate the flow rate or pressure, a globe valve may be the best choice, as it can provide accurate, stable, and repeatable control. However, both valves require proper installation, operation, and maintenance to ensure optimal performance and avoid safety or environmental risks. If you need help decidinghich valve to choose, consult a professional supplier or engineer who can provide you with the best options and solutions.