English

English

Get a Quote
Products

Hot Products

Company News

Three Common Causes of Valve Leakage and Emergency Remedies
Three Common Causes of Valve Leakage and Emergency Remedies
2025-05-28

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...

Can Oil Pass Through a Strainer? How Pre-Filtration Works in Lubrication Systems
Can Oil Pass Through a Strainer? How Pre-Filtration Works in Lubrication Systems
2025-05-20

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...

Are Ball Valves Suitable for Water Systems? A Practical Guide for Engineers & Installers
Are Ball Valves Suitable for Water Systems? A Practical Guide for Engineers & Installers
2025-04-30

Ball valves, with their simple structure, easy operation, and excellent sealing performance, have become widely used control components in both industrial and residential sectors. Particularly in water supply systems, an increasing number of engineers and installers are choosing ball valves as the primary fluid control device. But are ball valves truly suitable for water systems? How should one properly select and install them to ensure long-term stable operation? This article provides a comprehensive overview from the perspectives of structural principles, performance characteristics, and application recommendations. 1. Advantages of Ball Valves in Water Systems (1) Quick Opening and Closing Ball valves can complete the opening and closing operation with a simple 90° rotation, making them easy to operate and highly responsive—ideal for emergency situations or water systems that require frequent switching.   (2) Excellent Sealing Performance High-quality ball valves are equipped with PTFE or reinforced sealing materials, enabling zero leakage. They are particularly suitable for water supply systems in residential buildings, commercial complexes, and industrial facilities where sealing performance is critical.   (3) Compact Structure and Space-Saving Compared to gate valves or globe valves, ball valves occupy less space and offer flexible installation, making them ideal for water modules with high equipment integration.   (4) Strong Corrosion Resistance Ball valves made of stainless steel, brass, or plastic materials (such as UPVC) offer excellent corrosion resistance, capable of handling various water qualities (soft water, hard water, reclaimed water) and different additives.   2. Application Scenarios Analysis Ball valves are suitable for the following types of water systems: (1) Domestic Water Systems: Such as internal building water supply, point-of-use control for sanitary fixtures, and garden irrigation systems. (2) Industrial Water Systems: Such as cooling water circulation systems, boiler feedwater systems, and water supply for cleaning equipment. (3) Water Treatment Systems: Including reverse osmosis pretreatment, greywater recycling, and wastewater transfer processes. (4) Special Applications: High-pressure hot water systems or cleaning water containing chemical additives.   However, caution should be exercised in the following scenarios: (1) High-Frequency Modulation Conditions Standard ball valves are not suitable for precise flow regulation. It is recommended to use V-port ball valves or control-type electric ball valves. (2) Water Containing Sand, Gravel, or High Levels of Suspended Solids A Y-strainer should be installed to prevent particle blockage or damage to the sealing surfaces. (3) High-Temperature Hot Water Systems High-temperature ball valves with metal sealing structures should be selected to prevent seal aging and deformation.   3. Key Selection Criteria To ensure stable operation o...

Butterfly Valve
加载中...

20" 150LB Lined Butterfly Valve API 609 Lug ASME

20" 150LB butterfly valve is made according to API 609 standard. The valve body is made of WCB. Its connection mode is Lug. And it has turbine operation mode.

  • Payment:

    30% when order confirmed, 70% before shipment
  • Product Origin:

    China
  • Color:

    Customization
  • Shipping Port:

    Shanghai, China
  • Lead Time:

    30~60 days Ex Works after order confirmation
  • Material:

    ASTM A216 WCB
  • Method of Operation:

    Turbine Operation
Inquiry now
Product Detail

Product Description

Type

Butterfly Valve

Size

20"

Pressure

150LB

Connection

Lug

Operation

Turbine Operation

Body Material

ASTM A216 WCB

Design Norm

API 609

Face to Face Dimension

ASME B16.10

Flange Dimension

ASME B16.5

Test & Inspection Code

MFR

Temperature

-29 ~ 180°C

Applicable Medium

Acid, Alkali, Salt, etc.

Features

1. Modular design, convenient for maintenance and replacement, and cost saving;

2. Effectively eliminate leakage and make the valve achieve the best sealing effect.

Technical Drawing

Dimension Checking

Pressure Testing

Painting

Nameplate & Packing

Inspection report

Leave A Message

If you are interested in our products and want to know more details,please leave a message here,we will reply you as soon as we can.

Related Products
Cast Iron Concentric Butterfly Valve PTFE Lined
PTFE Lined Flanged Butterfly Valve 14 Inch Gearbox

The PTFE fully lined butterfly valve is made of cast iron body and with gearbox operation. The 14 inch flanged valve has concentric type structure. Quick Detail Type Butterfly Valve Size 14'' Design Pressure 150LB Construction Concentric Type, PTFE Lined Connection Type Double Flanged Operation Gear Operated Design Code API 609 Face to Face ASMEB16.10 End Connection ASMEB16.5 Test & Inspection API 598 Body Material Cast Iron GGG40 Temperature Range -15℃~+150℃ Application Water, Oil, Gas Related Knowledge What is the advantage of fully lined butterfly valve? The main advantage of lined butterfly valve is that it can handle abrasive and corrosive application at a relatively lower cost. The PTFE or PFA flexible seat provide a zero leakage sealing performance. Plus, the lined material PTFE has strong corrosion resistance, stable performance, low friction coefficient, which make the lined butterfly valve has a long service life. How does Dervos control quality of raw material? Raw material plays an important role in product quality. Likewise, casting and forging affect valve quality a lot. That is why Dervos pay a lot of attention to foundries. We have an approval list of foundries and classify them by certificates, scale, process and materials. To meet different requirements from customers, we could even appoint suitable foundries for our customers.

API609 PFA Lined Butterfly Valve LUG FF 20”150LB
API609 PFA Lined Butterfly Valve LUG FF 20”150LB

This 20 inch butterfly valve is plastic lined type one. Its PFA lined disc and its PTFE seat ring enable it a excellent corrosion resistant performance. With a gearbox, it is easy to drive.

Gate Valve
API602, SW Connection, 3/4'' 800LB Forged Steel Gate Valve, Body F316

3/4'' 800LB gate valve is made according to API 602 standard. The valve body is made of A182-F316. It has the structural characteristics of bolt cover, OS&Y. Its connection mode is SW. And it has hand wheel operation mode.

Line Blind Valve
1" - 60" Class 150 - 2500 Line Blind Valve ASME B16.34

Line blinds are utilized in pipeline systems when there is a need for either complete closure or unimpeded flow transition without a significant drop in pressure. The THD (Through-Hole Design) enables swift and seamless adjustments in position. The THD-slide variant boasts a multi-bolt configuration, making it easier to operate with reduced face-to-face dimensions. The inclusion of extra body bolts renders this style particularly well-suited for high-pressure applications.

handwheel operated globe valve
Cast Steel A350 Globe Valve BS1873 BW 8 Inch 300LB

The cast steel globe valve is designed as per BS1873. With Body Bonnet, outside screw and yoke, handwheel, the 8 inch valve, the valve is suitable for common work condition.

DIN Globe Valve Angle Type
Angle Type Globe Valve DN65 PN16 GS-C25 Rising Stem

The DN65 PN16 angle type globe valve is made of cast steel 1.0619 body and ss304 trim material, with rising stem, handwheel, RF flange.  Quick Detail Type Globe Valve Norminal Size DN 65 NorminalPressure PN 16 Construction Angle Pattern, BB ConnectionType Flanged Operation Handwheel Design Code DIN 3356 Face to Face EN 558 Connection EN1092 Test & Inspection EN12266 Body Material GS-C25 (1.0619) ApplicableTemp -29℃~+425℃ Application WOG Related Knowledge Why use an angle type globe valve? Angle globe valve turns the flow direction by 90 degrees without using an elbow or the extra pipe weld, which reduce the number of joints on the pipeline, save the installation time, and reduce the pressure drop & flow resistance. The angle pattern globe valve are used for application with periods of pulsating flow, since they are able to handle slugging effect. Our Main Product Range As an experienced supplier and vendor of industrial valves, Dervos supply cast steel valve, forged steel valve, cast iron valve, stainless steel valve, bronze valve, brass valve and alloy steel valve and so on, suitable for sea water, water, oil, and gas application.

Forged Steel 3 Piece Trunnion mounted Ball Valve 600 LB API6D
Forged Steel 3 Piece Trunnion mounted Ball Valve 600 LB API6D

The API 6D ball valve is designed with trunnion mounted ball and full bore structure. The flanged ball valve has 600LB design pressure and 10 inch nominal size with gearbox operation mode, conforming to NACE MR0175 requirement.

DN80 PN25 Cast Steel Gate Valve, Body 1.0619, EN1984
DN80 PN25 Cast Steel Gate Valve, Body 1.0619, EN1984, Handwheel

DN80 PN25 Cast Steel gate valve is made according to BS EN 1984 standard. The valve body is made of EN 10213 1.0619. It has the structural characteristics of insulation jacket with DN15 small flange. Its connection mode is EN1092-1 B. And it has Hand Wheel operation mode.

Wafer Check Valve
8" 150LB Dual Plate Wafer Check Valve 4A API594

8" 150LB check valve is made according to API 594 standard. The valve body is made of A995 4A. It has the structural characteristics of double disc and built-in type. Its connection mode is wafer.

Wafer Check Valve
DN50 PN40 Dual Plate Wafer Check Valve A105 API594

DN50 PN40 check valve is made according to API 594 standard. The valve body is made of A105. It has the structural characteristics of dual plate and wafer type. Its connection mode is wafer.

Globe Valve
1/2" 800LB Forged Steel Globe Valve SW F316/316L API602 Hand Wheel

1/2" 800LB globe valve is made according to API 602 standard. The valve body is made of ASTM A182 F316/F316L+STL. It has the structural characteristics of bolt cover, disc swivel plug, body seat and OS&Y. Its connection mode is SW. And it has hand wheel operation mode.

Trap Valve
DN20 PN40 Cast Steel Steam Trap Valve DIN RF WCB

DN20 PN40 steam trap valve is made according to GB/T22654-2008 standard. The valve body is made of WCB. It has the structural characteristics of inverted bucket steam trap and model L881F. Its connection mode is RF.

Leave a message

    If you are interested in our products and want to know more details,please leave a message here,we will reply you as soon as we can.

Home

Products

about

contact