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...

Plug Valve
加载中...

2" 150LB Four Way Plug Valve API599 WCB RF Multi Way

2" 150LB plug valve is made according to API 599 standard. The valve body is made of A216 WCB. It has the structural characteristics of four way and bolt cover. Its connection mode is RF. 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:

    A216 WCB
  • Method of Operation:

    API 599
Inquiry now
Product Detail

Product Description

Type

Plug Valve

Size

2"

Pressure

150LB

Connection

RF

Operation

Turbine Operation

Body Material

A216 WCB

Design Norm

API 599

End Flange Dimensions

ASME B16.5

Face to Face

Factory standards

Test & Inspection Code

API 598

Pressure-Temp

ASME B16.34

Temperature

≤ 120°C

Applicable Medium

Water, Oil and Gas

Features

1. Simple structure, small size, light weight, easy maintenance;

2. The sealing performance is not limited by the installation direction, and the flow direction of the medium can be arbitrary.

3. It is suitable for frequent operation and can be opened and closed quickly and easily.

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
Plug Valves For Natural Gas Service
Three Way Plug Valve Wrench 4 Inch 150LB RF Flanged

The 3 way plug valve is made of WCB body and stainless steel trim as per API 599. The plug valve that could connect any two ports together is applicable for natural gas service, water, oil and so on. Quick Detail Type Plug Valve Size 4'' DesignPressure 150LB Construction Three Way Type Plug Valve ConnectionType Flange Connection Operation Lever/Wrench Design Code API 599 Face to Face ASME B16.10 End Connection ASME B16.5 Pressure & Temp ASME B16.34 Test & Inspection API 598 Body Material A216 WCB TemperatureRange -29℃~+425℃ Application WOG Related Knowledge What are types of plug valves? Lubricated Plug Valve The plug gets lubricated by injecting sealant through injection fitting. The lubricant make sure the smooth movement and prevent the corrosion of plug. Usually, the seat of lubricated plug valve is metal, thus they can withstand higher temperature, available in larger size and higher pressure. Non-Lubricated Plug Valve A non-metallic sleeve or liner is installed in the body cavity of the plug valve. This sleeve reduce the fricion beween plug and body. Meanwhile it prevents the corrosion of plug. Due to non-metallice sleeve, the non-lubricated plug valve cannot be used in high temperature condition. Multiway Plug Valve The multiway plug valve is used for diverting flow in transfer lines. The multiway plug valves we often see are 3 way plug valve or 4 way plug valve. Dervos Packaging Based on sufficient experience, we have developed complete packing specifications and procedures to ensure clear and safe transportation so that you can receive good and sound products. And this is also an important factor that we earn good reputation from our customers.

Plug Valve
80A JIS 10K Three Way Plug Valve RF CF8 API599

80A JIS 10K three-way plug valve is made according to API 599 standard. The valve body is made of A351 CF8. It has the structural characteristics of 3-way and L-shaped. Its connection mode is RF.

Wafer Check Valve
24" 150LB Dual Plate Wafer Check Valve RF WCB API594

24" 150LB wafer check valve is made according to API 594 standard. The valve body is made of A216 WCB+316. It has the structural characteristics of dual plate and wafer type. Its connection mode is RF.

Dual Plate Wafer Check Valve API 594 DN250 10K
Dual Plate Wafer Check Valve API 594 DN250 10K

The double-disc check valve, made of A395 D1, has excellent resistance to corrosion. Designed in accordance with API594, the check valve is connected to pipes with WAFER. This valve is eligible to be put in marine working conditions.

4 150LB Gate Valve API603 Stainless Steel HW-OP OS&Y CF8M
4" 150LB Gate Valve API603 Stainless Steel HW-OP OS&Y CF8M

4" 150LB gate valve is made according to API 603 standard. The valve body is made of ASTM A351 CF8M+STL. It has the structural characteristics of bolt cover, elastic wedge and rising stem. Its test and inspection conform to API 598, and its operation mode is handwheel operation.

Check Valve
4'' Class 300 Nozzle type Non Slam Check Valve WCB

The stainless steel non return valve features in non slam type disc, INCONEL X750 spring, WCB valve body. This valve owns an excellent dynamic performance and minimizes vibrations and noise.

Flat Gate Valves
DN250 PN100 High-Pressure Flat Gate Valve with Drain Valve

It is a Carbon Steel full bore flat gatevalve with parallel wedge, DN250 PN100, made from LCC, one kind of low-temp carbon steel, which makes this valve capable to handle extreme working conditions.

Knife Gate Valve
2" 150LB Knife Gate Valve CF8 Lug Handwheel

2" 150LB knife gate valve is made according to MFS standard. The valve body is made of ASTM A351 CF8. It has the structural characteristics of bilateral sealing and with flow deflector. Its connection mode is lug. And it has hand wheel operation mode.

Gate Valve
API602 1" 800LB Forged Steel Gate Valve A105N SW

1" 800LB gate valve is made according to API 602 standard. The valve body is made of ASTM A105N. It has the structural characteristics of rising-stem. Its connection mode is SW. And it has the operation mode of installing electrical equipment with a light rod.

Globe Valve
Body 1.0619, DN50 PN16 Cast Steel Globe Valve, Handwheel, BS EN13709

DN50 PN16 cast steel globe valve is made according to BS EN 13709 standard. The valve body is made of EN 10213 1.0619. It has the structural characteristics of flat valve disc, body welded valve seat. Its connection mode is EN1092-1 B. And it has hand wheel operation mode.

3 600LB Stainless Steel Globe Valve BB RTJ CF8 Hand Wheel BS1873
3" 600LB Stainless Steel Globe Valve BB RTJ CF8 Hand Wheel BS1873

3" 600LB globe valve is made according to BS1873 standard. The valve body is made of ASTM A351 CF8+STL. It has the structural characteristics of bolt cover and straight through type. Its connection mode is RTJ. And it has hand wheel operation mode.

JIS Globe Valve Flanged
Marine Bronze Globe Valve DN32 5K FF Flanged

The DN32 JIS 5K globe valve is suitable for marine application. The bronze globe valve is handwheel operated with FF flange. Quick Detail Type Marine Globe Valve Size DN 32 Design Pressure 5K Connection Type FF Flange Design Code JIS F7301 Face to Face JIS B2002 Body Material Bronze Trim Material Bronze Application Water, Oil, Gas Purchasing System Late delivery time become a common issue in 2018. However, Dervos keep more than 90% on-time delivery, so how do we achieve that? It owns our purchasing department.  How do we react to a delay crisis? -Visit the factory everyday and supervise on site -Initiate related resources, such as machining workshops and skilled workers to help on expediting production What benefits could we do for you by keeping on-time delivery? -Avoid penalty from end user -Accumulate reputation -Gain client’s trust FAQ 1. Do you have your own foundry or forge shop?  No, but we have an approved list of foundries over the past decade of casting inspections, which can make sure that our castings are of good quality and all the raw materials are traceable.  2. Can you do NDE Capability radiography, MT, UT, LP? Of course, we can do all these tests upon our clients, but there will be additional charge to these tests. 3. What kind of test will you do for each order? After valve assembly, we will do hydraulic test for shell & sealing and air test. Plus, we will do dimension checking (face to face dimension, flange dimension) as per assembly drawing and standards.

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