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DERVOS 18th Anniversary | Eighteen Years of Progress, Moving Forward Together
DERVOS 18th Anniversary | Eighteen Years of Progress, Moving Forward Together
2026-07-03

In 2026, DERVOS VALVE proudly celebrates its 18th anniversary, marking an important milestone in the company's journey. To commemorate this occasion, DERVOS VALVE organized a three-day anniversary celebration, bringing together all employees to reflect on the company's achievements over the past eighteen years, look ahead to future development, and further strengthen team cohesion through meaningful activities and shared experiences.   Reflecting on 18 Years of Growth   From raw material management and precision machining to assembly and product testing, every stage of production reflects DERVOS VALVE's unwavering commitment to quality.   Over the past eighteen years, DERVOS VALVE has continuously improved its manufacturing system while enhancing product quality and customer service capabilities. Today, our industrial valves are widely used across the oil and gas, chemical, power generation, water treatment, LNG, and other industrial sectors, providing reliable valve solutions to customers worldwide.   Building Consensus for Future Development     During the anniversary celebration, DERVOS VALVE also held its mid-year communication meeting.   The meeting reviewed the company's performance over the first half of the year and outlined key objectives for future development. Representatives from different departments exchanged insights on production management, quality improvement, and cross-functional collaboration, sharing practical experience, reviewing achievements, and discussing future goals together.   The meeting further strengthened communication among departments, reinforced team alignment, and injected new momentum into the company's long-term development.     Embracing Nature Together   In addition to the company's anniversary activities, DERVOS VALVE organized a group excursion to experience the beauty of nature.   Surrounded by picturesque landscapes, employees enjoyed the scenic environment and explored the local culture in a relaxed and enjoyable atmosphere. The trip provided an opportunity to unwind while fostering stronger relationships among colleagues.   This memorable experience enriched the anniversary celebration, strengthened team spirit, and inspired everyone with renewed energy for the work ahead.     Eighteen Years of Commitment, Looking Ahead   Eighteen years represent not only growth and achievement, but also the beginning of a new chapter.     Since its establishment, DERVOS VALVE has remained dedicated to the design, manufacturing, and global supply of industrial valves. Through continuous improvements in product development, manufacturing capabilities, and quality management, the company has provided reliable valve products and technical support to customers across a wide range of industries worldwide.   Looking ahead, DERVOS VALVE will continue to focus on product innovation, manufacturing excellence, and long-term...

Best Ball Valves for Refinery Applications
Best Ball Valves for Refinery Applications
2026-06-23

Refineries operate under some of the most demanding process conditions found in the energy industry. High pressure, elevated temperature, sour media, corrosive fluids, and frequent thermal cycling place strict requirements on valve performance. In these environments, ball valves are widely used because they provide reliable shutoff, low pressure loss, and fast operation. However, selecting the best ball valve for refinery applications depends less on the valve type itself and more on matching the design to the process conditions.   Why Ball Valves Are Common in Refinery Service   Refinery units handle hydrocarbons, hydrogen, steam, sulfur compounds, and various aggressive chemicals. If bubble-tight isolation is required, then trunnion mounted ball valves are generally preferred for larger sizes and higher pressure classes because seat loading remains stable under differential pressure. Floating ball valves are more common in small-bore lines where compact dimensions and simple construction are advantageous.   API 6D and ASME B16.34 designs are frequently specified for refinery piping systems. Fire-safe construction in accordance with API 607 or API 6FA is often mandatory because accidental loss of soft seats must not result in external leakage. If the process medium contains hydrogen sulfide, then materials must comply with NACE MR0175 to reduce the risk of sulfide stress cracking.   Material Selection Depends on Process Media   Material compatibility is one of the primary factors affecting service life. Carbon steel valves are suitable for many hydrocarbon services, while stainless steel provides improved corrosion resistance in wet and chemically aggressive environments. Duplex and super duplex stainless steels are selected when chloride-induced corrosion becomes a concern.   If the process contains sulfur compounds or sour gas, then hardness control and material qualification become critical. In high-temperature applications, thermal expansion must be considered because excessive growth can increase operating torque and accelerate seat wear. If severe erosion is expected, then hard-faced balls and seats with tungsten carbide or chromium carbide coatings can significantly improve durability.   Sealing Performance and Failure Prevention   Soft-seated ball valves provide excellent shutoff performance, but seat materials determine their temperature limits. PTFE and reinforced PTFE are common in moderate-temperature services, while PEEK offers improved mechanical strength and higher temperature capability. If temperatures exceed the limits of polymer seats, then metal-seated ball valves become a more suitable solution.   Most valve failures in refineries are related to seat damage, stem leakage, or corrosion. If particulate contamination is present, then cavity fillers or metal seats may reduce wear. Double block and bleed configurations are often used where positive isolation is required for maintenance...

Fully Welded Ball Valve vs. Threaded Ball Valve: Which Offers Better Pressure Resistance?
Fully Welded Ball Valve vs. Threaded Ball Valve: Which Offers Better Pressure Resistance?
2026-06-11

In natural gas transmission, district heating networks, petrochemical facilities, and industrial utility systems, ball valves are widely used for reliable flow isolation. One of the most common questions during valve selection is: Which provides better pressure resistance—a fully welded ball valve or a threaded ball valve?   Understanding the Structural Difference Between Fully Welded and Threaded Ball Valves   From a structural perspective, fully welded ball valves generally offer higher pressure-bearing capability. The valve body is manufactured using a fully welded construction, eliminating threaded body connections and reducing stress concentration points associated with mechanical joints. Under high-pressure conditions, frequent pressure fluctuations, or significant temperature changes, the welded structure can provide greater mechanical integrity and more stable sealing performance. Threaded ball valves, by contrast, rely on threaded connections to assemble the valve body. While this design simplifies installation and maintenance, threaded joints are inherently more susceptible to stress and deformation. As system pressure increases or when vibration and thermal expansion-contraction cycles are present, threaded connections may become vulnerable to loosening, potentially resulting in external leakage. Common field indications include leakage around the stem packing area, seepage from body connections, or accelerated wear of sealing components.   Why Fully Welded Ball Valves Typically Offer Higher Pressure Resistance   The primary advantage of a fully welded ball valve lies in its one-piece welded body construction. Without threaded body joints, the valve can better withstand internal pressure loads and reduce the possibility of leakage caused by connection failure.   In applications involving high operating pressures, pressure surges, or repeated thermal cycles, the welded structure maintains better dimensional stability and structural strength. This is one of the key reasons why fully welded ball valves are widely used in gas transmission pipelines, district heating systems, and other critical infrastructure projects.   How Sealing Performance Affects Pressure Capability   In high-pressure service, valve failure is not determined solely by body strength. The sealing system also plays a critical role. Fully welded ball valves typically utilize an integral body design that minimizes potential external leakage paths and provides more consistent support for the seat sealing surfaces.   In threaded ball valves, small dimensional changes at threaded joints during long-term pressure cycling may affect seat loading, potentially increasing the risk of internal leakage. If significant leakage, abnormal deformation, or pressure test failure is observed, the valve should be removed from service and inspected immediately. For flammable, toxic, or high-temperature media, disassembly and maintenance under pre...

Globe Valv
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Bellow Seal Globe Valve 1.5 Inch 150LB Forged Steel

  • Product Origin:

    China
  • Color:

    Customization
  • Shipping Port:

    Ningbo/Shanghai,China
  • Lead Time:

    30~55 days Ex Works After Order Confirmation
  • Material:

    ASTM A105
  • Method of Operation:

    Handwheel
Inquiry now
Product Detail

The bellows seal globe valve adopts the bellows seal design, which completely eliminates the shortcomings of the normal valve stem packing seal aging and easy to leak, not only improves the energy efficiency, increases the safety of the production equipment, reduces the maintenance cost and frequent maintenance. It also provides a clean and safe working environment.Its simple structure and the low price makes it almost no "competitors". 


Quick Detail

Type

Globe Valve

Norminal Size

1.5 Inch

NorminalPressure

150LB

Construction

Bolted Bonnet, Outside Screw & Yoke, Rising Stem, Bellow Seal

ConnectionType

RF Flange

Operation

Handwheel

Design Code

ASME B16.34, API 602

Face to Face

ASME B16.10

Flange End

ASME B16.5

Test & Inspection

API 598

Body Material

ASTM A105

ApplicableTemp

-29℃~+425℃

Application

Water, Oil, Gas


Structure Feature

1. Double seal design (corrugated pipe + packing). If the bellows fails, the stem packing will also be avoided;
2. External leakage, and in line with international sealing standards;
3. No fluid loss, reduce energy loss, and improve plant equipment safety;
4. Long service life, reduce the number of maintenance, reduce operating costs;
5. Rugged bellows seal design, ensuring zero leakage of the valve stem, providing maintenance-free conditions.


Technical Drawing

Dimension


Our Service

Dervos customer service is one of our biggest competitive advantages. In Dervos, we provide-

 

1.Quotation within 24 hours or no later than 3 days

This will let you meet the quotation submission deadline and enhance your working efficiency

 

2.Weekly status report of your order

In this way, you will have a clear picture of your order. You do not need to waste time on pushing us for status update

 

3.An 18-month warranty period

A warranty certificate will issued after shipment and you will not have any concern after buying valves.

 

4.Solutions to complaints within 3 days

Quick and responsible actions to complaints will protect your reputation and reduce the financial loss as much as possible.


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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.

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Bellow Seal Globe Valve With Handwheel
Bellow Seal Globe Valve 1.5 Inch SW A105N OS&Y

The 1.5 inch 800LB bellow seal globe valve is designed with outside screw and yoke, handwheel operation, sw end. The reduced port globe valve is has forged steel A105N body. Design Feature 1.Outside screw and yoke 2.Rising stem 3.Bolted bonnet design 4.Bellow seal packing for reliable stem sealing 5.Reduced bore design 6.Handwheel Operated Quick Detail Type Globe Valve Size 1.5'' Design Pressure Class 800 Structure BB, OS&Y, Reduced Port, Bellow Seal Packing Connection Type Socket Weld Operation Handwheel Design Code API 602 End to End ASME B16.10 Connection End ASME B16.11 Pressure & Temperature ASME B16.34 Test & Inspection Standard API 598 Body Material Forged Steel ASTM A105 Trim Material Trim 8 Applicable Temperature -29℃~+425℃ Application W.O.G Origin China Related Knowledge What is a bellw seal valve? For bellow seal globe valves, the lower end bellows is welded on the valve stem to prevent the process fluid from eroding the valve stem. The other end is placed between the valve body and the valve cover to form a static seal. The double seal design ensure that if bellow seal pakcing fails, the stem packing will also function.  The bellow seal globe valves are applicable for media like steam, flammable, explosive, heat transfer oil, high purity, and toxic media etc. Special Tests Besides general tests we will do (hydraulic and air test), we could also do tensile strength test, metallographic test, fugitive emission test, and NDE test (UT,RT,PT,MT) upon customers’ specific requests.

Bellow Seal Globe Valve PN40
Cast Steel Bellow Seal Globe Valve DN65 PN40 1.0619

Dervos bellow seal globe valve is designed as per EN13709 with face to face dimesnsion per EN558. The special designed bellow seal make sure zero leakage from stem. Quick Detail Type Globe Valve Norminal Size DN 65 NorminalPressure PN 40 Construction Bolted Bonnet, Rising Stem, Bellow Sealed ConnectionType RF Flange Operation Handwheel Design Code EN13709 Face to Face EN 558 Connection EN1092 Test & Inspection EN12266 Body Material Carbon Steel 1.0619 Bellow Material SS304, SS316, SS316L and etc ApplicableTemp -29℃~+420℃ Application Water, Oil, Gas Structure Feature 1. Standard design of double-wall bellow seal 2. Heat-dissipating bonnet design; 3. With lubricant storage device; 4, With design of circlip to fix stem nut; 5. Reasonable product structure, reliable sealing performance and good appearance; 6. The sealing surface is welded with Co-based hard alloy, which has good wear resistance, corrosion resistance, anti-friction performance and long service life; 7. Stem has nitriding treatment with good corrosion resistance and anti-friction performance; 8. With position indicator for stem movement;

DN200 PN16 Bellow Seal Globe Valve, RF, Body 1.4408
DN200 PN16 Bellow Seal Globe Valve, RF, Body 1.4408, EN13709

DN200 PN16 Bellow Seal Globe valve is made according to BS EN 13709 standard. The valve body is made of EN 10213 1.4408. It has the structural characteristics of body cover bolt, rising pole bracket, angle type, corrugated pipe seal and structural length of 255mm. Its connection mode is RF. And it has hand wheel operation mode.

1 300LB Forged Steel Bellows Globe Valve LF2 RF API602
1" 300LB Forged Steel Bellows Globe Valve LF2 RF API602

1" 300LB Forged Steel Bellows Globe Valve is made according to API602 standard. The valve body is made of A350-LF2+316. It has the structural characteristics of Welded Bonnet, Rising Stem (OS&Y), Bellows Type. Its connection mode is RF. And it has Handle Wheel operation mode.   Product Parameters   Type Forged Steel Bellows Globe Valve Size 1” Pressure 300LB Connection RF Operation Hand wheel Body Material A350-LF2+316 Design Norm API602, ASME/B16. 34 Face to Face ASME/B16.10 Flange dimension conform ASME B16.5 Test & Inspection Code API598 Temperature -46 ~ 345°C Applicable Medium Water, Oil and Gas   Features 1. LF2 forged steel body offers excellent low-temperature toughness and structural reliability for 300LB service.   2.Bellows-sealed globe valve design compliant with API 602 eliminates stem leakage and ensures safe, precise flow control.   Technical Drawing Dimension Checking Pressure Testing Nameplate & Packing    

Bellows Sealed Globe Valve PN16 DN200 EN 13709 HandWheel
Bellows Sealed Globe Valve PN16 DN200 EN 13709 HandWheel

PN16 DN200 Sealed Globe Valve is made according to EN 13709 standard. The valve body is made of 1.4408. It has the structural characteristics of Bolted Body-Bonnet, OS&Y, Angle Type, Bellows Sealed. Its connection mode is RF. And it has Hand Wheel  operation mode.   Product Parameters   Type Sealed Globe Valve Size DN200 Pressure PN16  Connection RF Operation Hand Wheel Body Material 1.4408 Design Norm EN 13709 Face to Face Client's Std. Flange Ends BS EN 1092-1 B1 Test & Inspection Code BS EN 12266 Temperature -60 ~ 300°C Applicable Medium Water, Oil and Gas   Features 1.DIN Bellows Sealed Stop Valve PN16 DN200 EN 13709 provides zero stem leakage with bellows sealing design, ideal for hazardous and high-purity media applications (bellows sealed stop valve DN200 PN16). 2.Handwheel Operated Bellows Globe Valve ensures precise manual control and long service life, suitable for industrial systems requiring reliable isolation (EN 13709 bellows sealed valve DN200).   Technical Drawing Dimension Checking Pressure Testing Spectrum Nameplate & Packing Inspection Report

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    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.

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