Dervos here announce that we officially go back to work on Feb 3rd, 2020. Currently, we are working at home due to influence of Coronavirus outbreak. We will return to our office on Feb 10th,2020. We also launch a donation activity for against Coronavirus. Please refer to the link below for further information. Dervos Donation Plan

In the past two weeks, the whole country have been uniting together to fight against Coronavirus outbreak in China. We learn that due to a severe shortage of medical supply in domestic, many medical staff will work for more than 4 consecutive hours without drinking water or going to washroom to save masks and protective clothing as much as they can. Dervos people want to do something for our country. We have a donation plan to offer medical supply to frontline. If you have related resources, we here invite you to join us and help us purchase medical supply like masks abroad. We will pay for the cost. Below is a letter of our formal request. If you are interested in our donation plan, just send us email at virus-shooter@dervosvalve.com. We appreciate all your kindness and care in advance!!!

Double eccentric butterfly valve is further improved on the basis of single eccentric butterfly valve. Its structural feature is that the axis of the valve stem deviates from both the center of the disc and the center of the body. The effect of double eccentricity enables the butterfly plate to detach from the valve seat immediately after the valve is opened, which greatly eliminates unnecessary excessive squeezing and scraping of the disc and seat, reduces the opening resistance, extends valve seat life. The double eccentric butterfly valve also adopts metal seat, which improves the application in high temperature field. Double eccentric butterfly valve is also called high performance butterfly valve. It is mainly used for drainage of water plants, power plants, steel plants, chemical engineering, water source engineering, environmental facilities and other systems. Structural features of high performance double eccentric butterfly valve: 1. Reasonable design, compact structure, easy assembly and disassembly, and easy maintenance. 2.Eccentric structure is adopted to reduce the friction of the seal ring and prolong the service life of the valve. 3, Completely sealed, zero leakage. Can be used in ultra-high vacuum conditions. 4. Replace the seal ring, disc, shaft to different materials, which can be used for a variety of media and different temperatures.

Here came our travel season on Dec, 2019. This year we decided to travel by cruise and have a tour in Vietnam. We are excited to travel together. In the cruise, we enjoyed the entertainment: we did Rock Climbing, we sang and danced, we played High altitude project, and had a Christmas party, the most important moment is that we counted down the last few second of 2019. When we disembarked, we visited the beautiful scenery. To us, Vietnam is a quiet country which you could relax yourself and dig yourself into the scenery. Here we also saw lots of foreigners came and join us. “Work hard, play harder”is our company motto. This is the most important time of everyone in Dervos and also the happiest time we hang out together to end this year with some happy memory.

Big news! The share of Xiamen Dervos Valves Industry Co.,ltd is officially listed through Xiamen Cross-Strait Equity Exchange on Sep 23rd, 2019 with ticker 861601. This time we have finished the increased capital registration of 381,508 shares. This event marks a big step in company development. In the future, Dervos will make more achievements with collective efforts of all Dervos people.

SPE and DPE are different types of ball valve seats. Ball valve with DPE (Double Piston Effect) seals both at upstream or/and at downstream. When ball valves with DPE seats needs to achieve cavity over-pressure automatically, a extra pressure relief device need to be installed. Ball  valves with SPE ( Single Piston Effect) seals only at upstream. And will release the cavity over-pressure automatically to the pipeline. DBB ( Double Block and Bleed) and DIB(Double Isolation and Bleed) are different forms of valves. The ISO/API definition of DBB reads as follows: "single valve with two seating surfaces that, in the closed position, provides a seal against pressure from both ends of the valve with a means of venting/bleeding the cavity between the seating surfaces".  The definition for DIB reads as follows: "single valve with two seating surfaces, each of which, in the closed position, provides a seal against pressure from a single source, with a means of venting/bleeding the cavity between the seating surfaces".   The definition of DIB isn't very clear all by itself, so it's best to read it concurrently with the requirements of the DIB testing in Annex B for clarification. In short, DBB is valve with both side SPE seat, and DIB-1 is valve with both side SPE seat, and DIB-2 is valve with one side SPE seat and one side DPE seat. DIB-1 is a test performed on a valve where both seats are uni-directional (DPE) and a DIB-2 test is performed on a valve with one seat uni-directional (SPE) and one seat bi-directional (DPE).  Both DIB-1 and DIB-2 are optional tests, and must be requested in order for the test to be performed.  So, either a DIB-1 or a DIB-2 test will test the effectiveness of a DPE seat. DBB Trunnion Mounted Ball Valve