The butterfly valve, as a compact, quick-opening, and low-resistance regulating valve, is widely used in industries such as water supply and drainage, HVAC, power, chemical, and paper-making. However, in practical engineering applications, improper consideration of the butterfly valve’s installation direction and spatial arrangement often leads to valve operating abnormalities, decreased sealing performance, and deviations in control accuracy. In severe cases, it can even cause system failures or frequent maintenance, resulting in unnecessary economic losses. Therefore, a correct understanding of the impact of installation orientation and spatial layout on butterfly valve performance is essential to ensure its reliable operation and extend its service life.     1. The Impact of Installation Orientation on Butterfly Valve Performance   (1) Fluid Flow Direction and Its Effect on Sealing Performance For centerline butterfly valves, where the valve disc rotates around the valve shaft, the force is relatively symmetric, and the fluid flow direction has little impact on the sealing performance. Therefore, the flow direction requirement is not strict during installation. However, for eccentric butterfly valves, especially double-eccentric and triple-eccentric types, the seal design is based on the "flow-assisted compression" principle. That is, when the medium pressure comes from the specified direction, it pushes the valve disc toward the sealing seat, thereby enhancing the sealing effect.   If the valve is installed in the opposite direction of the flow arrow marked by the manufacturer, the reverse fluid flow will wash the valve disc. Not only will the expected sealing effect not form, but it may also create gaps between the sealing surfaces, accelerate valve seat wear, and cause internal leakage, making it impossible to close the valve completely. Therefore, the installation of eccentric butterfly valves must strictly follow the flow direction requirements.   (2) Valve Shaft Orientation and Its Effect on Opening/Closing Torque and Actuator The installation orientation of the valve shaft (horizontal or vertical) has a significant impact on the opening/closing performance, valve body stress, and actuator life. Most medium and small-sized butterfly valves are installed with the valve shaft in the horizontal position. This method facilitates the alignment of the valve body with the pipeline and the arrangement of the actuator.   However, for large-diameter butterfly valves or those installed in high locations or vertical pipelines, the valve shaft is often vertical. In this position, the weight of the valve disc directly acts on the valve shaft, especially when the valve disc is in the open position, where its center of gravity deviates from the axis, creating a large eccentric torque and increasing the axial load during opening and closing. If the actuator does not account for this additional load, it may result in po...

In industrial production, valves are critical components for fluid control, and their sealing performance directly impacts system safety and stability. Leakage not only reduces operational efficiency but may also lead to fluid escape, posing serious safety risks. This article outlines three common causes of valve leakage and provides corresponding emergency response recommendations to help you quickly identify issues, take action, and mitigate risks.   1. Seal Surface Wear or Damage   Cause: During long-term operation, sealing pairs (e.g., valve seat and disc, valve ball and seat) suffer from media erosion, particle abrasion, or corrosion, leading to uneven sealing surfaces and resulting in minor or significant leakage. Emergency Measures: · Minor Leakage: Adjust compression force (e.g., tighten bonnet bolts) to temporarily reduce leakage. · Severe Leakage: Immediately shut down the system to replace or regrind sealing components; replace the entire valve if necessary. Prevention Recommendations: Conduct regular inspections, select valves with appropriate materials and wear-resistant designs. For media containing solid particles, use hard-sealing structures.   2. Packing Aging or Gland Loosening   Cause: Valve stem sealing uses packing materials (e.g., graphite, PTFE), which may age, dry, or crack over prolonged use. Temperature fluctuations can also cause gland loosening, leading to leakage at the packing box.  Emergency Measures: · Tighten packing gland bolts to increase packing compression. · If ineffective, add or replace packing material. · Avoid over-tightening to prevent increased operating torque or stem damage. Prevention Recommendations: Regularly replace packing; select materials compatible with the media and operating temperature. For critical equipment, consider spring-loaded packing glands.   3. Casting Defects or Corrosion Perforation in Valve Body/Bonnet   Cause: Some low-quality valves have casting defects such as sand holes or shrinkage cavities. Prolonged exposure to corrosive media can cause localized perforation of the valve body, resulting in uncontrollable leakage. Emergency Measures: · For small leaks, temporary repairs using metal adhesives or cold welding are possible. · Large-scale damage requires immediate valve replacement. · For high-pressure or toxic/hazardous media, no pressurized repair is allowed; follow shutdown procedures strictly.  Prevention Recommendations: Purchase valves from reputable manufacturers; use corrosion-resistant materials (e.g., 304/316L stainless steel). Perform regular wall thickness inspections on critical pipelines.   Common Questions & Answers (Q&A)   Q1: Can all valve leaks be fixed by replacing packing?A: No. Packing replacement is effective only when leakage is due to packing aging or gland loosening. If the leakage stems from seal surface or valve body damage, other me...

In any efficient and reliable lubrication system, oil cleanliness is a core factor affecting equipment lifespan and operational efficiency. Strainers, as the front-line filtration devices in lubrication systems, play a critical role in pre-filtration. However, engineers and operators often raise the following questions: Can oil pass through strainers smoothly? What exactly is the function of a strainer? How does it differ from subsequent fine filters?   This article systematically explains the role of strainers in lubrication systems, covering their working principles, pre-filtration objectives, and practical applications across different systems.   1. Can Oil Pass Through a Strainer?   Answer: Yes, but with limitations.   (1) Strainer Structure Allows Oil Flow A strainer is fundamentally a low-precision filter made of stainless steel mesh or perforated metal plates. It features uniform pores, typically sized between 80–500 μm (micrometers), allowing most clean oil to flow through unimpeded.   (2) Contaminants Are Blocked Particles such as metal shavings, seal fragments, and carbon deposits in the oil are intercepted by the strainer, preventing them from entering the oil pump or other critical components.   (3) Oil Temperature and Viscosity Affect Flow Efficiency Low temperatures or high-viscosity oil may reduce flow rates or even cause blockages. This is one reason for low oil pressure during system startup.   2. Objectives and Significance of Pre-Filtration   (1) Protecting the Oil Pump Internal pump components (gears, impellers, or plungers) are highly sensitive to solid particles. Pre-filtration prevents particles from entering the pump, avoiding premature wear or seizure.   (2) Reducing Load on Primary Filters By intercepting large contaminants, strainers allow primary filters (e.g., oil filter cartridges) to focus on finer impurities, extending their service life and maintaining stable system flow.   (3) Lowering System Failure Rates Pre-filtration reduces risks such as pump failure, orifice blockages, and lubrication breakdown caused by foreign particles, enhancing overall system reliability.   3. Typical Applications of Pre-Filtration Devices   Application System Strainer Installation Position Strainer Type Internal Combustion Engine Lubrication Oil sump → Pump inlet Coarse metal strainer Hydraulic Systems Tank outlet → Pump suction port Suction strainer or basket strainer Turbine Lubrication Systems Pump inlet Dual-chamber switchable suction strainer Transmission/Clutch Systems Oil sump → Circulation pump inlet Perforated plate + magnetic strainer   4. Design and Usage Considerations for Strainers   (1) Pore Size Selection Must Align with System Precision Requirements 80–100 μm: Typical for engine oil systems. 150–300 μm: Used in hydraulic equipment. >400 μm:  Suitable for low-pressure or open-loop systems.   (2...