English

English

Get a Quote
Products

Hot Products

Company News

Business Team Visits Europe for In-Depth Customer Engagement
Business Team Visits Europe for In-Depth Customer Engagement
2025-11-20

Recently, representatives from Dervos Valve visited long-term industrial valve partners in Norway, Italy, Germany, and Spain. The multi-day trip focused on understanding customers’ current project requirements and discussing future procurement plans and technical specifications in greater depth.     In Norway, our team was invited to visit the customer’s equipment installation workshop and valve application site. Through direct discussions with the engineering and procurement teams, we gained a clear understanding of their concerns regarding high-pressure applications, material selection, and delivery schedules. The customer noted, “Dervos has an excellent grasp of our project needs. Your quick response and professional recommendations give us great confidence.” This feedback reflects not only trust in our product quality but also strong recognition of our service capabilities.   The team then traveled to Italy for technical discussions with our local partners and visited their valve assembly and testing facilities. Our representatives introduced Dervos’s manufacturing capabilities, quality inspection processes, and ongoing product enhancements across ball valves, gate valves, butterfly valves, and check valves. The Italian customer remarked, “The solutions you presented are highly practical and will significantly improve the reliability of our projects.” Such positive feedback further strengthened the confidence in our partnership.   Through this trip, Dervos gained deeper insights into the European market’s expectations regarding valve performance, quality control, and delivery reliability. We will continue to refine our products and services based on customer feedback, ensuring that every partner receives a reliable and fully tailored one-stop valve solution.   Looking ahead, Dervos Valve will remain committed to our service philosophy of listening to customers, responding quickly, and delivering real value. With higher product standards and more professional technical support, we aim to strengthen and advance our cooperation with customers around the world.

Maintenance Tips to Extend the Service Life of Butterfly Valves
Maintenance Tips to Extend the Service Life of Butterfly Valves
2025-11-14

Butterfly valves are widely used as regulating and shut-off devices in industrial piping systems, valued for their simple structure, lightweight design, and rapid open-close operation. They find applications across water treatment, chemical, metallurgical, power, oil, and gas industries.   However, even high-quality butterfly valves can experience performance degradation if proper maintenance is neglected over long-term operation.This article explores the structural features, common issues, and maintenance practices to help effectively extend the service life of butterfly valves.   1. Understanding the Operational Characteristics of Butterfly Valves   A butterfly valve primarily consists of a valve body, disc, stem, sealing elements, and an actuator. Its operation relies on the rotation of the disc, driven by the stem, to control fluid flow.   During operation, the disc remains immersed in the fluid, subject to erosion, corrosion, and pressure shocks. Therefore, the valve’s lifespan is closely related to sealing performance, material selection, and the operating environment.   2. Common Factors Affecting Butterfly Valve Lifespan   Frequent Operation and High Differential Pressure High-frequency cycling or prolonged operation under high pressure and flow velocity can cause valve seat wear and stem seal aging.   Corrosive Media and Sediment Build-Up Chemical fluids or particulate-laden media can corrode the disc and clog sealing surfaces, reducing smooth operation.   Improper Installation Misalignment between the valve and pipeline, or uneven bolt tightening, may lead to eccentric disc friction and damage to sealing elements.   Lack of Regular Maintenance Neglecting routine cleaning and lubrication can increase operating torque, accelerate seal wear, and shorten the valve’s overall service life.   3. Maintenance Tips to Extend Butterfly Valve Lifespan   1. Proper Installation as the Foundation Ensure the valve body is aligned with the pipeline center to avoid eccentric stress. Use appropriate gaskets between the valve and flange to prevent localized stress. For actuated butterfly valves, confirm correct travel adjustment to avoid exceeding torque limits.   2. Regular Cleaning and Inspection Periodically remove deposits and debris from the disc surface to prevent seal surface damage. Check stem packing and seals; replace immediately if signs of aging are detected. For pipelines carrying particulate-laden media, flush the valve regularly to prevent clogging.   3. Lubrication and Corrosion Protection Apply grease to the stem, bearings, and drive components regularly to maintain smooth operation. For valves operating in seawater or corrosive environments, select corrosion-resistant coatings or materials such as aluminum bronze or duplex stainless steel.   4. Proper Operation and Control  Avoid rapid or forced operation to prevent disc deformation from impact. If the ...

Check Valve Maintenance: When to Replace and How to Fix Common Issues
Check Valve Maintenance: When to Replace and How to Fix Common Issues
2025-11-06

A check valve is a critical device that prevents backflow, widely used in water treatment, oil & gas pipelines, chemical processing, and steam systems.   After long-term operation, check valves may experience issues such as leakage, vibration noise, or sticking. If not addressed promptly, these problems can reduce system efficiency and even cause equipment damage or safety hazards.   So, how can you tell if a check valve needs replacement? Which faults can be repaired, and which require a full replacement? This article provides a systematic guide.   1. Basic Operating Principle of Check Valves   The primary function of a check valve is to automatically prevent backflow. When fluid flows in the intended direction, the valve disc is pushed open by pressure; when flow reverses, the disc closes automatically, using either its own weight or a spring, preventing backflow.   Common types include: Lift Check Valve Swing Check Valve Dual Plate Wafer Check Valve Ball Check Valve    Although their designs vary, the key criteria for determining whether a check valve needs replacement remain the same: sealing performance, operational smoothness, and structural integrity.   2. How to Determine if a Check Valve Needs Replacement   Visible Leakage (Internal or External) If fluid continues to flow backward when the valve is closed, it indicates significant wear or deformation of the sealing surfaces, preventing an effective seal. If the leakage exceeds system tolerances and cannot be corrected by cleaning or resurfacing, the valve or its sealing components should be replaced.   Sticking or Inflexible Valve Disc After long-term operation, the valve stem, guides, or disc may become stuck due to scaling, corrosion, or debris. If cleaning, descaling, or lubrication fails to restore smooth operation, replacement is recommended.   Excessive Noise or Vibration Frequent opening and closing or rapid disc rebound can cause vibration or knocking sounds. This is usually due to spring failure, loose valve components, or worn guides. Persistent or frequent noise should trigger inspection of the valve’s structural integrity and consideration for replacement.   Corroded or Cracked Valve Body or Cover Exposure to acidic, alkaline, or high-temperature fluids can corrode or crack the valve body, compromising structural strength and posing safety risks. Such damage cannot be repaired and requires full valve replacement.   Frequent Backflow or Abnormal System Pressure Fluctuations Poor sealing or delayed valve response can cause system pressure variations, including water hammer. If repeated adjustments do not resolve the issue, it indicates aging of the internal spring or disc mechanism, necessitating timely replacement.   3. Common Fault Diagnosis and Solutions   Fault: Valve fails to close completely, causing backflow Cause: Worn sealing surfaces, deformed disc, or trapped debris Solution: Remove ...

Ball Valve
加载中...

DN100 PN25 3-Way Floating Ball Valve RF CF8M ISO17292

DN100 PN25 ball valve is made according to ISO 17292 standard. The valve body is made of A351-CF8M. It has the structural characteristics of T-shaped, floating ball, anti-fire, anti-static, anti-flying valve stem, bi-directional. Its connection mode is RF. And it has lever with dial 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:

    A351-CF8M
  • Method of Operation:

    Lever with dial
Inquiry now
Product Detail

Product Description

Type

Ball Valve

Size

DN100

Pressure

PN25

Connection

RF

Operation

Lever with dial

Body Material

A351-CF8M

Design Norm

ISO 17292

Face to Face Dimensions

Manufacturer's Standard

Flange Ends Dimensions

BS EN 1092-1

Fire Safe

API 607

Test & Inspection Code

API 598

Temperature

-29 ~ 120°C

Applicable Medium

Water, Oil and Gas

Features

1. Low fluid resistance, simple structure, small volume, and light weight;

2. Tight and reliable, with good sealing, convenient operation and maintenance.

Technical Drawing

Dimension Checking

Pressure Testing

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
Stainless Steel Multiport Ball Valve
3 Way Ball Valve Stainless Steel T Port 3 Inch

The 3 way T type ball valve owns flange connection, gearbox, ss304 body, ball and stem. The 3 inch flanged ball valve features in its T type three way ports which could connect any pair of ports or three ports together. Quick Detail Type Ball Valve Size 3" Pressure ANSI 300 Construction Three Way Ball Valve Connection Flanged Connection Operation Mode Gearbox Body Material A182 F304 Manufacture and Design API 6D Pressure & Temp ASME B16.34 End to End Code ASME B16.10 End Connection ASME B16.5 Inspection API 6D, API 598 Temperature Range -29℃~+200℃ Medium WOG Related Knowledge What is the difference between T port and L port 3-way ball valve? Normally speaking, 3-way ball valve can be divided into T type and L type.  A T port three-way ball valve can connect any two ports, and even connect all three ports together at the same time. However, an L port three-way ball valve can only connect the center port with either side port or disconnect three ports. FAQ 1. Can the orders always be delivered on time? Our purchasing team follows up very closely with each order to make sure on-time delivery for most of orders. In 2018, more than 90% orders were delivered on time, and we are dedicated to doing better.  2. What’s the normal delivery lead time?  For normal material, usually the delivery time is about 35~40 days, and for forged material, the delivery can even be shortened to 20~25 days. We believe the short lead time can make our offer more competitive and help you secure more orders. 3.Do you have different price levels for us? With our numerous suppliers, different price levels are available with us, so we are able to help you win more customer from different markets requesting for high, medium and low prices.

DN100 PN10 3-Way Floating Ball Valve Type RF
DN100 PN10 3-Way Floating Ball Valve Type RF

The DN100 3 way ball valve is isolating valve designed to redirect the service fluid flow rather than throttling or regulating purposes. Suitable for water, steam, gas, oil, crude oil, acid, alkali and other liquids and gases without mechanical impurities.

T Port DN150 PN16 3-Way Ball Valve RF
T Port DN150 PN16 3-Way Ball Valve RF

  A three-way ball valve has three ports or openings that are connected to piping or tubing for gas or fluid flow (media) to pass through. 

Cast Steel Gate Valve Class 600
16 Inch Flanged Gate Valve WCB Rising Stem API 600

The 16 inch cast steel gate valve with gearbox and 600LB RF flange is designed as per API 600. The bolted bonnet gate valve features in rising stem, resilient wedge and metal seat. Quick Detail Type Gate Valve Size 16" Pressure Class600 Construction Bolted Bonnet, Rising Stem, OS&Y, Flexible Wedge, Metal Seat Connection RF Flange Operation Gearbox Design Code API 600 Face to Face ASME B16.10 Flange End ASME B16.5 Pressure & Temp ASME B16.34 Test & Inspection API 598 Body Material A216 WCB TrimMaterial Trim 5 Temperature Range -29℃~+425℃ Medium Water, Oil and Gas Origin China Dimension & Material Class 600 NPS in 2 2 1/2 3 4 6 8 10 12 14 16 18 20 24 DN mm 50 65 80 100 150 200 250 300 350 400 450 500 600 L-L1 (RF-BW) in 11.5 13 14 17 22 26 31 33 35 39 43 47 55 mm 292 330 356 432 559 660 787 838 889 991 1092 1194 1397 L2 (RTJ) in 11.625 13.125 14.125 17.125 22.125 26.125 31.125 33.125 35.125 39.125 43.125 47.25 55.375 mm 295 333 359 435 562 664 791 841 892 994 1095 1200 1407 H (OPEN) in 18.625 21.75 23.375 28 1/16 38 3/16 44 3/16 52.375 59 13/16 68.125 72.25 90.125 98 13/16 119 mm 474 553 593 713 970 1122 1330 1519 1730 1835 2290 2510 3022 W in 9.875 9.875 11 13/16 13.75 19 11/16 22 1/16 28.375 24 24 24 24 30 30 mm 250 250 300 350 500 560 720 610* 610* 610* 610* 760* 760* WT (kg) RF 41 58 88 131 253 413 623 784 1288 1820 2150 2540 4080 BW 35 50 68 104 208 328 496 637 1120 1448 1828 2201 3360 *Manual gear operator is recommended No Part Name Carbon steel to ASTM Alloy steel to ASTM Stainless steel to ASTM WCB LCB WC6 WC9  C5 CF8 CF8M CF3 CF3M 1 Body A216 WCB A350 LCB A217 WC6 A217 WC9 A217 C5 A351 CF8 A351 CF8M A351 CF3 A351 CF3M 2 Seat Ring A105 A350 LF2 A182 F11 A182 F22 A182 F5 A182 F304 A182 F316 A182 F304L A182 F316L 3 Wedge A216 WCB A350 LCB A217 WC6 A217 WC9 A217 C5 A351 CF8 A351 CF8M A351 CF3 A351 CF3M 4 Stem A182 F6 A182 F6 A182 F304 A182 F304 A182 F316 A182 F304L A182 F316L 5 Bonnet nut A194 2H A194 4 A194 7 A194 8 6 Bonnet bolt A193 B7 A320 L7 A193 B16 A193 B8 7 Gasket SS Spiral Wound graphite or SS Spiral Wound PTFE 8 Bonnet A216 WCB A352 LCB A217 WC6 A217 WC9 A217 C5 A351 CF8 A351 CF8M A351 CF3 A351 CF3M 9 Backseat bushing A182 F6 A182 F6 A182 F304 A182 F304 A182 F316 A182 F304L A182 F316L 10 Stem packing Graphite or PTFE 11 Lantern A182 F6 A182 F6 A182 F304 A182 F304 A182 F304 A182 F304 A182 F316 A182 F304L A182 F316L 12 Gland Nut A194 2H A194 8 13 Gland Eyebolt A193 B7 A193 B8 14 PIN Carbon steel or Stainless Steel 15 Gland A182 F6 A182 F304 A182 F316 A182 F304L A182 F316L 16 Gland Flange A216 WCB A351 CF8 17 Stem Nut A439 D2 or B148-952A 18 Nipple Carbon steel or Stainless Steel 19 Retaining Nut Carbon steel 20 Hand Wheel Ductile Iron or carbon steel 21 Name Plate Stainless steel or Aluminum 22 H.W.Lock Nut Carbon steel

Floating Ball Valve
1 Inch 800LB Floating Ball Valve Stainless Steel SW

Dervos manufactures a versatile range of Ball Valves in single, two and three piece constructions. The valves are available in full-bore and regular-bore designs, in a variety of end connections and materials to meet your requirements.

Swing Check Valve
BS1868 10" 150LB Swing Check Valve FF UNS N08031

10" 150LB check valve is made according to BS1868 standard. The valve body is made of ASTM UNS N08031. It has the structural characteristics of bolt cover and swing type. Its connection mode is FF.

Cryogenic Floating Ball Valve 4Inch 300LB RF Lever
Cryogenic Floating Ball Valve 4Inch 300LB RF Lever

The 4 inch cryogenic ball valve, designed as per API609, has many parts equipped RPTFE --It has the lowest coefficient of friction and the best corrosion resistance of any known plastic material, so that the valve can handle quite extreme situations.

Class 150 Floating Ball Valve
Aluminum Bronze Floating Ball Valve 1 Inch 150LB

The 1 inch floating type ball valve is made of aluminum bronze C95800. The reduced bore ball valve has lever operation, RF flange, two piece type body. Quick Detail Type Ball Valve Size 1" Pressure ANSI 150 Construction Floating Ball, 2-Piece Body, Side Entry, Reduced Bore Connection Flanged End Operation Lever Operation Body Material Aluminum Bronze ASTM B148 C95800 Media W.O.G Available Modifications for Ball Valve -Nominal Pressure -Valve Size -Reduced Port & Full Port -Material of Body, Ball, Stem, Seat, Packing, Bolt and Nut -Valve Operation (Lever, Gearbox, Pneumatic or Hydraulic or Electric Actuator) -End Connection Type -Available Extended Stem -Customized Coating & Packaging -Modifications of Drain Port Dervos Packaging Good packing means good first impression. Just imagine how do you feel differently when seeing two boxes below? And you will know the reason why in Dervos we value packaging so much. In Dervos, we make sure- 1.Every valve is clean and dry. What do we do? -Clean the valve before packing -Add anti-rust oil -Add flange cover 2.No damage to valves in delivery. How do we achieve this? -Fix the valve with iron wire -Separate the valve with soft material -Layer the valve with plywood 3.Strong box and clear shipping mark

DN25 PN63 Forged Steel Globe Valve
DN25 PN63 Forged Steel Globe Valve EN1092-1 B1 A105N H.W.

Forged Steel Globe Valve is made according to BS 5352 standard. The valve body is made of A105N+STL. It has the structural characteristics of through way type, bolt bonnet. Its connection mode is EN1092-1 B1. And it has hand wheel operation mode.

Butterfly Valve
API 14" 150LB High Performance Double Eccentric Butterfly Valve WCB

14" 150LB butterfly valve is made according to API 609 standard. The valve body is made of WCB. It has the structural characteristics of double eccentric and high performance. Its connection mode is lug type. And it has turbine with locking device operation mode.

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