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Ring Out 2020 & Ring In 2021
Ring Out 2020 & Ring In 2021
2020-01-05

Time keeps moving forward, and we get the last day of 2020. As you may have seen, there are a lot of red elements in the following pictures. In Chinese culture, red stands for fortune and luck. We at Dervos all dress in red this day, wishing 2021 would be a red new year for us. It happened to be a Friday, and we finished work early in the afternoon and started to clean our respective work areas. It is kind of a traditional activity in China, sweeping out the old things and welcoming the coming year with a new look. Posting window decalsis also an indispensable work. Helena, the girl in the right pic below, was finishing the phrase that pretty much says new year new luck. Another girl was showing her amazing handcraft job. Count down 3, 2, 1. Finally we get through the terrible 2020 and step into a brand new 2021. Human society artificially divides time into days, months and years. That demonstrates our wishes to left the bad in the past and embrace the unknown future by the alternation of the old and the the new. Although 2020 is a bumpy year, Dervos maintains a positive mindset for the following 2021 and wishes our customers, in the new year, endless luck and joys.

Special Cleaning Requirements for Cryogenic Valves
Special Cleaning Requirements for Cryogenic Valves
2020-12-30

Cryogenic valves are intended for very cold applications. The term "cryogenic" refers to temperatures below -50゜C.   Valve materials for cryogenic service are required for good ductility. Sealing parts, gaskets and other fittings should also be adapted to these extremely cold conditions on demand.   Industries associated with liquefied and compressed natural gas, as well as liquid oxygen, nitrogen or helium, rely on these special valves for the frequent, safe and reliable transport of cryogenic liquids and gases.   Special Cleaning Needs & Concerns To Be Stressed   The valve manufacturers are required to remove grease and all organic contaminants from the valve with a special solvent, keeping the valve clean. Ultrasonic cleaning is a common choice.   Some cleaning gases such as oxygen or chlorine require a very high level of cleanliness to ensure that no organic material or fiber breaks remain on the valve after the cleaning. The cleaned and certified valves are placed in double-sealed polyethylene bags to ensure that the valves are stored in a clean environment until they are installed and used.   Operators should perform a thorough inspection when installing cryogenic valves. This is critical to ensure that no lubricants or grease are accidentally introduced into the valve. Some specialty lubricants are available for use in cryogenic environments, and whether or not they are allowed should depend on the specific application requirements.   As mentioned earlier, cryogenic valves must avoid staining with fiber breaks. As a general rule, fibers longer than 1/8 inch are not allowed in the valve. In many cases, fibers or breaks of any length are not allowed in the valve.   Finally, inspectors should regularly check cryogenic valves and oxygen systems to see if there are internal or external leaks. Internal valve leaks can be prevented by installing the valve properly and a reliable seal design. Cryogenic service requires robust and stable seals to ensure long-lasting and reliable operation of the equipment. Here at Dervos, we’re a leading provider for products inindustrial valve, and we’re certified with the CE, ISO, API and other institutions. We strive to offer the best quality products and customer service through our extensive experience. Contact us today for more information.

Case Review: DERVOS DN3750 BUTTERFLY VALVE FOR INDIAN GOVERNMENT PROJECT
Case Review: DERVOS DN3750 BUTTERFLY VALVE FOR INDIAN GOVERNMENT PROJECT
2020-12-24

The biggest valve Dervos has made ever. This is a DN3750 butterfly valve Dervos made forBombay Municipal Corporation in 2017 which is a government project. The project is special and challenging for its operation for suchalarge size of DN3750. As its torque isup to 989954N.m,it isbetter to be automatically actuated instead of manual operation. But as where it was going to serve is outreach of electrical power, manual operation is the only choice we have. After accurate calculation of the torque, finally we came up with a solution that DN3750 would be operated by a combination of total four gearboxes,which reduced theinput torqueinto incredible117N.m. What an amazing job we did! Andfor this valve, many tests had been carried out, including but not limited to below: We had done DP to the seat ring, UT to flanges, disc and stem, and RT to the welding. Besides, we had done strength tests to disc, adhesive tests to the painting, and IP68 Submergence Test by merging the gearboxes into 3-metre deep water by 72hours. And movement tests were also witnessed, it took about 9 hours from fully open to fully close position. Eventually,The completed valve was made out as about 58 tons weight and 82.4 CBM. Besides the remarkable work we did, we're so proud that its successful put-in-use was even reported by the local newspaper in Mumbai. As you can conclude, Dervos is indeed a professional and reliable valve provider. Contact us today, and get you the quality products and outstanding services Dervos offers.

WCB Changeover Valve PN40 Handwheel
加载中...

WCB Changeover Valve PN40 Handwheel

The changeover valve is combined by two valves that are different from nominal diameter--one is DN100, the other is DN150. A handwheel is put on the right side of the valve to help control the large WCB-made device. Designed as per DIN 3356, the valve is usually put in the oil industry.

  • 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:

    ASTM A216 WCB
  • Method of Operation:

    Handwheel
Inquiry now
Product Detail

General Discrption

Changeover , also called selector valve, is a three way device usually for changing the direction of the flow in pipelines. It also can be put in the situation of two safety valves and a pressurized system as a pressure relief system where the changeover valve ensures that we always have one standby valve ready for emergency. The condition also permits regular maintenance can be carried out without interrupting the work of the whole device.


The simple design from Dervos allows easy assembly, dis-assemble and easy maintenance. The valve also can handle various applications--high temperatures, cryogenic service, dangerous fluids and many others.


Design Features

Full Bore: The full-bore channel brings superior transporting performance. This valve is also designed to minimize the pressure drop and flow-resistance.


Zero Leakage: With emission-free packing and the static sealing part of the body, which is double-sealed by oval-ring and metal jacketed graphite gasket, the valve meets the demands of corresponding working conditions.


Long service life: The valve enjoys easy maintenance and long service life, which benefits from the plane sealed sealing face of the valve and the alloy welding technology.


Quick Detail

Type

Changeover Valve

Nominal Diameter

DN100*150

NominalPressure

PN40

Construction

Bolted Bonnet

Connection

RF

Operation

Handwheel

Design & Manufacture

DIN 3356

End to End 

TO MFT’S STD

Flange End Dimension

EN 1092-1 B1

Test & Inspection 

EN 12266-1

Temperature Range

-29℃~+425℃

Body Material

ASTM A216 WCB

Big Disc

ASTM A105+13Cr

Media

W.O.G.etc


 

Technical Drawing

 

Dervos Quality Checking System

In Dervos, we control quality throughout the whole manufacturing process.

 

Casting inspection:

We can find out the problem of raw material, such as shoddy casting, unqualified wall thickness, chemical composition and so on, which ensure that you will not be cheated.  


Machining Inspection:

On the one hand, we could ensure machining accuracy through this process. On the other hand, we could find out machining mistake as early as possible, to win more time for repairing and remaking

 

Final Inspection:

Final inspection activities include document and QC record review, visual examination, dimension check, pressure test, painting and packing check. You don’t need to come and inspect in person and all the documents could be provided as proof. 

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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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