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...

Gate Valve
加载中...

Pressure Seal Gate Valve 2 Inch 4500 LB SW API 602

The high-pressure Class 4500 gate valve is designed with PSB and SW end connection. Made of CS A105, the 2 inch gate valve follows the inspection standard API 598 and design standard API 602.
Dervos could offer customizing service by providing clients with valves in different sizes, materials, standards, design pressure, structure, operation type and connection type.

  • 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:

    CS A105
Inquiry now
Product Detail

Product Description

Type

Gate Valve

Size

2"

PN

Class 4500

Construction

Pressure Seal Bonnet, OS&Y

Connection

SW

Operation

Handwheel

Body 

CS A105

Design Standared

API 602

Face to Face Code

ANSI B16.10

Pressure & Temp 

ANSI B16.34

Test & Inspection

API 598

Temp.

-29℃   ~   +425℃

Medium

Water, Oil and Gas

Origin

China

Material


Product Range

Our products include different kind of valves as below. Or you want to know more detail, just contact us.

Quality Inspection

Dervos strictly controls product quality. In addition to the final round of inspections, our quality inspection team also checks valve quality through casting or forging, machining, pressure testing, dimensional inspection, painting and packaging.

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
Pressure Seal Bonnet Gate Valve
Pressure Seal Bonnet Gate Valve BW 8 Inch 2500LB

The 8 inch Class 2500 gate valve is designed with pressure seal bonnet, butt weld connection, and gearbox operation. The 8 inch gate valve has carbon steel WCB body and trim 5. Quick Detail Type Gate Valve Size 8'' Design Pressure ANSI 2500 Construction Pressure Seal Bonnet, Flexible Wedge, Metal to Metal Seat ConnectionType Butt Weld (SW) OperationType Gearbox Operation Body Material A217 WC6 TrimMaterial Trim 5 Design Code API 600 Face to Face Dimension ASME B16.10 End Connection ASME B16.25 Pressure & Temp ASME B16.34 Medium Water, Oil and Gas Origin China Dimension & Material NPS      DN Class 2 2 1/2 3 4 6 8 10 12 14 16 18 20 24 50 65 80 100 150 200 250 300 350 400 450 500 600 L(RF) 900LB 368 419 381 457 610 737 838 965 1029 1130       1500LB 368 419 470 546 705 832 991 1130 1257 1384       2500LB 451 508 578 673 917 1022 1270             L1(BW) 900LB 216 254 305 355 508 660 787 914 991 1092 1346 1473 1600 1500LB 216 254 305 406 559 711 864 991 1067 1194 1697     2500LB 279 330 368 457 610 762 914 1041 1118 1245       L2(RTJ) 900LB 371 422 384 460 613 740 841 968 1038 1140       1500LB 371 422 473 549 711 841 1000 1146 1276 1407       2500LB 454 514 584 683 927 1038 1292             H(Opne) 900LB 554 637 680 796 1084 1372 1494 1550 1960 2210       1500LB 554 637 767 875 1094 1372 1655 1834 2150 2260 2460 2721 2940 2500LB 610 654 753 850 1254 1374 1685 1894 2226 2382 2585     W 900LB 300 350 350 400 560 460* 610* 610* 610* 760*       1500LB 300 450 450 560 305* 460* 610* 610* 760* 760*       2500LB 500 500 600 600 460* 460* 610*             Weight   (RF) 900LB 50 84 92 154 341 622 950 1295 1720 2380       1500LB 60 91 128 182 394 795 1370 2120 2800 3870       2500LB 121 175 195 229 720 1295 2250             Weight   (BW) 900LB 39 64 82 120 266 524 760 1090 1450 2018       1500LB 46 71 85 130 292 578 974 1615 2010 2815 3315 4150 5219 2500LB 88 135 144 158 500 892 1550 1978 2580 3780 5988     *Manual gear operator is recommended No. Part WCB WC6 WC9  C5 CF8 CF8M 1 Body A216 WCB A217 WC6 A217 WC9 A217 C5 A351 CF8 A351 CF8M 2 Seat A182 F6a A182 F22 A182 F22 A182 F5 A182 F304 A182 F316 3 Wedge A216 WCB A217 WC6 A217 WC9 A217 C5 A351 CF8 A351 CF8M 4 Stem A182 F6a SAEHNV3 A182 F304 A182 F316 5 Stuffing Box A216 WCB A217 WC6 A217 WC9 A217 C5 A351 CF8 A351 CF8M 6 Seal Ring ANSI 316L Flexible Graphite+316 7 Split Ring Steel F6 F6 F6 A182 F304 F316 8 Back Ring Steel Steel Steel Steel SS SS 9 Bolt A193 B7 A193 B7 A193 B7 A193 B7 A193 B8 A193 B8 10 Nut A194 2H A194 2H A194 2H A194 2H A194 Gr.8 A194 Gr.8 11 Yoke A216 WCB A217 WC6 A217 WC9 A217 C5 A351 CF8 A351 CF8M 12 Bolt A193 B7 A193 B7 A193 B7 A193 B7 A193 B8 A193 B8 13 Nut A194 2H A194 2H A194 2H A194 2H A194 Gr.8 A194 Gr.8 14 Packing Plate ANSI 410 ANSI 410 ANSI 410 ANSI 410 ANSI 304 ANSI 316 15 Packing Flexible Graphite(Braided and Ring) or PTFE 16 Split Pin Steel Steel Steel Steel Steel Steel 17 Eyebolt A193 B7 A193 B7 A193 B7 A193 B7 A193 B8 A193 B8 18 Gland A182 F6 A182 F6 A182 F6 A182 F6 A182 F304 A182 F316 19 Gland Flange A105 A105 A105 A105 A182 F304 A182 F316 20 Nut A194 2H A194 2H A194 2H A194 2H A194 Gr.8 A194 Gr.8 21 Stud A193 B7 A193 B7 A193 B7 A193 B7 A193 B7 A193 B7 22 Stem Nut Ni-resist A439-D2 23 Gear Box Purchased 24 Protector Steel 25 Nameplate ANSI 304 26 Rivet ANSI 304

Gate Valve
8" 1500LB Pressure Self Sealing Gate Valve WCC BW

8" 1500LB gate valve is made according to ASME B16.34 standard. The valve body is made of WCC. It has the structural characteristics of pressure self sealing, elastic gate and structural length of 711mm. The working principle of self sealing valve is mainly to use wedge sealing surface to seal under pressure.

Gate Valve
Pressure Seal Gate Valve 10'' 1500LB WCC BW PSB

10'' 1500LB gate valve is made according to ASME B16.34 standard. The valve body is made of WCC. It has the structural characteristics of pressure self sealing, rising stem, elastic wedge and structural length of 864mm. Both ends of the valve stem are threaded. It has BW connection type.

Plug Valve
API 6D Inverted Plug Valve LCB 8 Inch 600 LB Gearbox

The 8 inch plug valve is designed per API 6D with Class 150 RF flange and gearbox operation. The inverted plug valve is made of LCB. Dervos could offer customizing service by providing clients with valves in different sizes, materials, standards, design pressure, structure, operation type and connection type. Quick Detail Type Plug Valve Size 8'' Design Pressure 600LB Construction Inverted Type, Lubricated Type, Pressure Balanced Connection RF Flange Operation Gearbox Design Code API 6D Face to Face ANSI B16.10 End Connection ANSI B16.5 Test & Inspection API 598 Body Material LCB Temperature Range -46℃~+425℃ Application Water, Oil and Gas   Dimension

Gate Valve
DN15 PN40 F53 Forged Steel Gate Valve HandWheel

DN15 PN40 gate valve is made according to EN ISO 15761 standard. The valve body is made of ASTM A182 F53. It has the structural characteristics of rigid wedge, full bore, rising stem, bolted cover. Its connection mode is EN1092-1 B1. And it has hand wheel operation mode.

Swing Check Valve
1" 150LB Forged Steel Flange Swing Check Valve API 602 A105

1" 150LB swing check valve is made according to API 602 standard. The valve body is made of A105. It has the structural characteristics of bolt cover, swing type and full bore. Its connection mode is RF (Welded Flange).

Wafer Check Valve
16" CL150 Dual Plate Wafer Check Valve CF8M API594

16" CL150 check valve is made according to API594 standard. The valve body is made of A351 CF8M. It has the structural characteristics of dual plate. Its connection mode is wafer.

Steam Trap Valve
DN15 PN40 Bimetal Steam Trap Valve A105 RF GB/T22654

DN15 PN40 steam trap valve is made according to GB/T22654-2008° standard. The valve body is made of A105. It has the structural characteristics of bimetal type and BK47-Y model. Its connection mode is RF.

Plug Valve
1" 600LB Inverted Pressure Balance Lubricated Plug Valve API 6D

1" 600LB plug valve is made according to API 6D standard. The valve body is made of A105. It has the structural characteristics of oil sealed and full bore. Its connection mode is FNPT. And it has handle (with locking device) operation mode.

Wafer Check Valve
API594 3" 150LB Dual Plate Wafer Check Valve API598 LCC

3" 150LB wafer check valve is made according to API594 standard. The valve body is made of A352 LCC + 316. It has the structural characteristics of double plate and built-in type. Its connection mode is wafer type.

Floating Ball Valve
Body A105, DN15 PN16 Floating Ball Valve, FNPT Connection, Lever Operation, ASME B16.34

DN15 PN16 floating ball valve is made according to ASME B16.34 standard. The valve body is made of A105. It has the structural characteristics of floating ball, full bore, anti-fire and anti-static. Its connection mode is FNPT. And it has lever operation mode.

Strainer
3" 1500LB Y Type Strainer WCB RTJ ASME B16.34 BC

3" 1500LB strainer is made according to ASME B16.34 standard. The valve body is made of ASTM A216 WCB. It has the structural characteristics of plug with DN20 blind flange. Its connection mode is RTJ.

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