Get a Quote

Hot Products

Company News

Gain a Deeper Understanding of Buried Soft-seated Gate Valves
Gain a Deeper Understanding of Buried Soft-seated Gate Valves

Buried soft-seated gate valves are critical valves widely employed in pipeline systems, featuring unique designs and functionalities that render them extensively utilized across various industrial and domestic applications. Working principle The working principle of buried soft-seated gate valves is based on the sealing performance between the gate and the sealing surface. When the valve is in the closed position, the gate is pushed against the sealing surface by the actuating mechanism, typically a handwheel or electric actuator, achieving complete closure of the pipeline. When it is necessary to open the valve, the actuating mechanism pulls the gate away from the sealing surface, allowing the medium to flow freely in the pipeline. Structural characteristics 1. Subterranean Design: Buried soft-seated gate valves are typically installed underground within pipeline systems to shield the valves from external environmental impacts. Simultaneously, this design maximizes space conservation and ensures unobstructed pipeline flow. 2. Soft-Sealing Structure: Soft-sealing materials typically utilize rubber or polymers, offering excellent sealing performance and corrosion resistance. They can maintain a stable sealing effect across various media and temperatures. 3. High Pressure Endurance: The design structure of buried soft-seated gate valves is robust, capable of withstanding high pressure and impact forces, ensuring stable and reliable operation under various operating conditions. 4. Anti-corrosion Coating: Valves are typically coated with anti-corrosion coatings on their surfaces to enhance durability and lifespan, thereby reducing maintenance costs. 5. Complete Accessory Configuration: Buried soft-seated gate valves are typically equipped with accessories such as handwheels, electric actuators, limit switches, etc., to meet operational requirements under different conditions. Application area 1. Petroleum and Chemical Industry: Used for control and regulation of crude oil, natural gas, and chemical media. 2. Municipal Water Treatment Systems: Used for flow control and prevention of backflow in municipal water distribution networks. 3. Wastewater Treatment Plants: Used for drainage and regulation in wastewater treatment systems. 4. Thermal Power Plants: Used for flow control in boiler feedwater pipelines and cooling water systems. 5. Urban Heating Systems: Used for regulation and control of heat transfer media in centralized heating networks. Buried soft-seated gate valves play a crucial role as integral components in pipeline systems across industrial and civilian domains. Their reliable sealing performance, stable structural design, and extensive application areas make them indispensable in pipeline systems. This article aims to help readers gain a comprehensive understanding and application of buried soft-seated gate valves, thereby enhancing the safety and operational efficiency of pipeline systems.

What is a Tilting Disc Check Valve?
What is a Tilting Disc Check Valve?

The tilting disc check valve is a common type of valve used in pipeline systems to prevent reverse flow of the medium. It typically consists of components such as the valve body, disc, spring, and sealing gasket. The working principle of the tilting disc check valve is based on the design of the disc: the disc is positioned at an angle, allowing the medium to flow smoothly through the valve in the forward direction, while swiftly closing the valve in the event of reverse flow, thereby preventing backflow of the medium. One of the characteristics of the tilting disc check valve is its simple structure. Due to the fewer components and compact layout, manufacturing and maintenance are relatively easy. Additionally, the tilting disc check valve has the capability of quick closure. When there is a change in the flow direction of the medium, the disc promptly responds and closes the valve, effectively preventing backflow of the medium and maintaining the normal operation of the pipeline system. Another significant feature is its excellent sealing performance. The tilting disc check valve employs devices such as springs to assist in closing the disc, ensuring effective sealing of the valve in the closed position, thus preventing medium leakage and safeguarding the safe operation of the pipeline system. Furthermore, tilting disc check valves are typically manufactured using corrosion-resistant materials, enabling them to operate stably in corrosive media over the long term. Another notable feature of the tilting disc check valve is its wide range of applications. It is suitable for various media, including liquids, gases, and steam, and is widely used in industries such as water supply, drainage, chemical, and petroleum. Whether in low-pressure systems or high-pressure systems, tilting disc check valves can reliably prevent medium backflow, protecting the safety operation of pipelines and equipment. In summary, the tilting disc check valve plays a crucial role in pipeline systems due to its characteristics of simple structure, rapid closure, excellent sealing performance, corrosion resistance, and wide applicability. When designing and selecting valves, considering factors such as the working pressure of the pipeline system, characteristics of the medium, and operating environment, choosing the appropriate tilting disc check valve can effectively enhance the safety and stability of the pipeline system.

Specific Requirements for Installing Fully Welded Ball Valves in Underground Pipelines
Specific Requirements for Installing Fully Welded Ball Valves in Underground Pipelines

The installation requirements of fully welded ball valves in underground pipelines are crucial, as the unique characteristics of the underground environment pose higher demands on the performance and safety of the valves. Proper installation not only ensures the normal operation of the valves but also prolongs their service life and enhances the safety and reliability of the pipeline system. The following are the specific requirements for installing fully welded ball valves in underground pipelines: 1. Selecting the appropriate valve type When installing fully welded ball valves in underground pipelines, it is necessary to choose the appropriate valve type based on the operating conditions and fluid characteristics of the pipeline system. Fully welded ball valves, with advantages such as simple structure and reliable sealing, are suitable for high-pressure, high-temperature, and corrosive fluid applications in pipeline systems. 2. Underground burial depth consideration When installing fully welded ball valves, it is imperative to consider the depth of underground burial. Typically, the burial depth of underground pipelines should comply with relevant standards and specifications to ensure the valves are positioned securely while facilitating maintenance and operation. 3. Corrosion protection measures The dampness of the underground environment and the presence of chemicals in the soil can lead to corrosion and damage to valves. Therefore, when installing fully welded ball valves, it is necessary to implement appropriate corrosion protection measures. This includes selecting valves manufactured from corrosion-resistant materials and applying corrosion-resistant coatings to the valves to extend their service life. 4. Sealing performance requirements Fully welded ball valves in underground pipeline systems must possess excellent sealing performance to prevent fluid leakage and contamination of groundwater sources. During installation, it is imperative to ensure that the valve's sealing components are intact and properly installed to ensure that the sealing performance meets design requirements. 5. Consideration of groundwater level fluctuations Fluctuations in groundwater levels may affect the operational status and safety of fully welded ball valves. When selecting installation locations, it is essential to consider the range of groundwater level fluctuations and implement corresponding waterproofing measures to prevent groundwater from affecting the valves. 6. Regular inspection and maintenance The underground environment has a significant impact on fully welded ball valves; therefore, regular inspection and maintenance of the valves are essential. Inspection tasks include assessing the sealing performance of the valves, checking the condition of moving parts, evaluating the effectiveness of corrosion protection measures, and promptly addressing any issues to ensure the safe operation of the valves. When installing fully welded ball valves in unde...

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.

  • Payment:

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

  • Color:

  • Shipping Port:

    Shanghai, China
  • Lead Time:

    30~60 days Ex Works after order confirmation
Inquiry now
Product Detail


1. Swift Transition: Blinding can be performed safely in a matter of minutes, even by operators with minimal experience.

2. Economical Solution: Decreases maintenance hours, resulting in savings on labor costs.

3. Toolless Handling: The process is simplified with a hand-wheel operation, eliminating the need for tools to achieve full shut-off.

Standard Specifications


1'' - 60'' (DN 25 to DN 1500)

Pressure Class

Class 150 - 2500 (PN 2.5 to PN 400)

Design & Manufacture code

ASME B16.34

Flange Standard

ASME B16.5


Carbon Steel, Stainless Steel, Hastelloy, and Titanium


Manual, Pneumatic Hydraulic and Electric

Technical Drawing

Adaptable Design

In addition to its conventional design, the THD-Slide is available in variations tailored for High-Temperature, Fire Safety, and Non-Drip applications. For installations constrained by limited space, a compact version can be provided as well.

Easy Seal Inspection

In this design, the seals are housed within the spectacle plate. This characteristic offers the advantage of convenient access for inspection and seal replacement. Assessing the condition of these seals can be performed external to the operational process, prior to any position changes, thereby ensuring the integrity of the seal's quality.

Cost Effectiveness

The THD-Slide features a straightforward and robust design engineered to deliver complete shutdown, extended operational lifespan, and cost-effective service with minimal maintenance requirements. The distinctive mechanism for opening and closing the THD-Slide enables a single individual to rapidly and safely blind pipelines without the need for any tools or equipment.

THD-Slide Cutout

Part Description

Part Description





A182 F6A

Stem Nut

Alloy Copper


A350 LF2

Seal Carrier

A350 LF2

Seals in plate


Spectade Plate

A350 LF2+ENP

Position Stop

A193 B7

Driving module

A350 LF2

Body stud/Nuts

A193 B7/A194 2H

Other materials and seal rings are available upon request


●Hand Wheel Extensions

●Locking Device

●Limit Switches

●Drain/Vent ports

●Spectacle Plate Covers to Protect Seals

●Compact Design (integral tapped end flange)

●Rain/Dust Shield

●Torque Limiter

Operation of Standard

Mechanism Principle

In normal conditions, the blind valve's diversion hole is in contact with the pipeline, and the blind valve is in the open position. When maintenance is required, and the pipeline must be cut off, then loosen the stem of blind valve to move the flat end onto the pipeline, and make the blind valve turn to closed position from open position; tighten the stem and let the blind valve to perform sealing function and cut off the pipeline.

When the maintenance work is completed, loosen the stem and move the blind plate to the diversion hole and connected to the pipeline. The blind valve was turned to closed position from open one. Lock the stem, and seal it, the pipeline is now open, and the blind plate valve returns to the open position.

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
line blind valve
8" Class 150# Line Blind valve ASME DIN ISO Carbon Steel

Line blind valve (eyeglass valve) is a kind of gate valve that cuts off gas medium manually, electrically or pneumatically or hydraulically. It is generally divided into electric blind valve, hydraulic blind valve, closed plug valve and electric open blind valve.

Line Blind Valve
DN50 CL150 High Temperature Cam-Slide Line Blind Valve Stainless Steel

Line blind valve is a kind of gate valve that cuts off gas medium manually, electrically or pneumatically or hydraulically. It is generally divided into electric blind valve, hydraulic blind valve, closed plug valve and electric open blind valve.

JIS 2 Piece Floating Ball Valve RF×NPT 25A 16K
JIS 2 Piece Floating Ball Valve RF×NPT 25A 16K

This ball valve, designed as per ASME B16.34, features two different connection ways--one side for RF and the other side NPT. The valve with floating ball, PTFE seat, SCS13 body and other features has an excellent sealing performance.

Ball Valve
API6D DN50 PN160 Floating Ball Valve Lever A105

DN50 PN160 floating ball valve is made according to API6D standard. The valve body is made of A105. It has the structural characteristics of floating ball and structural length of 235mm. It has a lever operation mode and its connection mode is lens gasket.

Piston Flanged Check Valve
Cast Steel GS-C25 Piston Lift Check Valve PN16 RF Flange

The cast steel lift non return check valve is designed with piston type disc, bolted bonnet, and PN16 RF flange. The spring loaded check valve conforms to DIN 3356. Quick Detail Type Check Valve ( Non-return Valve) Nominal Diameter DN 150 NominalPressure PN 16 Construction Lift Type / Piston Type, Bolted Bonnet Connection Flanged Connection Design & Manufacture DIN 3356 End to End EN 558 Connection EN 1092 Test & Inspection EN 12266 Body Material Carbon Steel GS C25 Media W.O.G. Product Range Body material: CS, SS, Alloy Steel, CI, Bronze, Brass  Size Range: 2”~12” (DN50~DN300) End Type: Butt Weld, Socket Weld, Flanged, Screwed Pressure Range: 150lbs~2500lbs (PN16~PN420) Temperature Range: -46℃~ +425℃ Related Knowledge What is a piston check valve? Usually, we have swing type check valve and lift type check valve. A piston check valve and ball check valve both belong to lift type check valve. In a lot of cases, a piston check valve use spring to retain the disc in closed position. The structure of a piston check valve is very similar to the globe valve just without manual operation.  Due to its piston type disc and superior leak tight characteristic, the piston check valves are suitable for small size and high pressure conditions.

Butterfly Valve
API 609 Metal Seated Butterfly Valve CF8 12 Inch 150LB Gearbox

The 12 inch 150 LB triple eccentric butterfly valve is designed per API 609 with flange end and gearbox operation. The valve is made of stainless steel CF8 with metal seat design. Quick Detail Type Butterfly valve Size 12 Inch Pressure 150LB Construction Triple Offset/Eccentric, Metal Seat Connection Type Flange Operation Gearbox Design Code API 609 Face to Face ANSI B16.10 End Connection ANSI B16.5 Test & Inspection API 598 Body Material CF8 Applicable Temp -196℃~+800℃ Application Water, Oil, Gas Materials Dimension  

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.

Lift Check Valve
Forged Steel Flanged Lift Check Valve 1 Inch 150LB

The forged steel lift check valve is designed with class 150 pressure and 1 inch nominal size according to standard API 602. We also call it as piston check valve. Quick Detail Type Check Valve Size 1'' DesignPressure 150LB Construction Lift Type, Piston Type Connection RF Flange Design & Manufacture API 602 End to End ASME B16.10 Connection ASME B16.5 Pressure & Temp ASME B16.34 Test & Inspection API 598 Body Material ASTM A105N Trim Material Trim 5 Temp Range -29℃~+425℃ Media W.O.G. Dimension Checking Pressure Tesing Packing

Lift Check Valve
1" 2500LB Pressure Self Sealing Lift Check Valve FNPT F316L

1" 2500LB check valve is made according to ASME B16.34 standard. The valve body is made of F316L. It has the structural characteristics of lifting type, pressure self-sealing, conventional diameter. Its connection mode is FNPT.

Globe Valve
6" 300LB Cast Steel Globe Valve BB BW WCB API598

6" 300LB globe valve is made according to BS1873 standard. The valve body is made of WCB. It has the structural characteristics of straight through, bolt cover, parabolic disc, standard flow, body valve seat. Its connection mode is BW. And it has handwheel operation mode.

Wafer Check Valve
4" 150LB Dual Plate Wafer Check Valve CF8M Wafer API594

4" 150LB wafer check valve is made according to API 594 standard. The valve body is made of A351 CF8M+STL. It has the structural characteristics of double disc. Its connection mode is wafer.

DN250 PN40 DIN Y Type Strainer RF 1.0619 EN13709

DN250 PN40 Y-type strainer is made according to EN13709 standard. The valve body is made of EN 10213 1.0619. It has the structural characteristics of Y-type. It 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.