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

We set up a team to visit Indonesia during 13~20th, Oct, 2019. We planned this trip for such a long time, from presentation to documents, to clothes etc. We also investigated this market in advance and all clients in this country. By this way, we selected valuable clients to meet us. To be honest, before going to Indonesia, we know little about this market. We are confused about the conflict: the data shows this market is potential, while from our experience, we did not get lots of order from this market. That’s why we really want to explore this market. After 7 days, we came back with our understanding about this market, we know much more about Indonesia. There are two levels in Indonesia; high level only cares about brand, and low level only care about price.  There is no doubt that this is a new way for us to do business， and we will keep investigating other markets in the future. 

The Preparation of Ball Valve before Installation 1. Ensure that the pipeline at the installation position of the ball valve is in the coaxial position. The two flanges on the pipeline should be parallel, and confirm that the pipeline can bear the weight of the ball valve. 2. Check whether there are impurities and welding slag in the pipeline, and the regulating valve must purge the pipeline. 3. Check the nameplate of the ball valve, and fully open and close the ball valve for several times to confirm that the valve can work normally, and thoroughly check all the details of the valve to ensure that the valve is intact. 4. Remove the protective cover at both ends of the valve, check whether the body is clean, clean the body cavity, because the sealing surface of the ball valve is ball shape, even small debris may cause damage to the sealing surface. Installation of Ball Valve 1. Any section of the ball valve can be installed in the upstream end, Shanghai nimei ball valve handle ball valve can be installed in any position of the pipeline, if equipped with actuator (such as gear box, electric-pneumatic actuator) ball valve, it must be installed vertically, valve inlet and outlet in a horizontal position. 2. Between the ball valve flange and the pipeline flange according to the design requirements of the pipeline with sealing gasket. 3. Bolts on the flange shall be tightened symmetrically, successively and uniformly. 4. If the ball valve with pneumatic, electric and other actuators, according to the manual to complete the installation of air source, power supply. Inspection After Installation Of Ball Valve 1.After installation, start the ball valve open and close several times, should be flexible, uniform force, ball valve work normally. 2. According to the design requirements of pipeline pressure, test the sealing performance of the joint surface of ball valve and pipeline flange after passing through pressure. Ball Valve Maintenance 1. Only by removing the pressure before and after the ball valve can the ball valve be disassembled and decomposed. 2. In the decomposition and reassembly process of the ball valve, it is necessary to protect the sealed parts, especially non-metallic parts, such as o-ring and other parts, with special tools. 3. Bolts must be tightened symmetrically, step by step and evenly when the ball valve body is reassembled. 4. Cleaning agent should be compatible with rubber parts, plastic parts, metal parts and working medium (such as gas) in the ball valve.When the working medium is gas, gasoline (gb484-89) can be used to clean the metal parts.Clean nonmetallic parts with purified water or alcohol. 5. The decomposed individual parts can be cleaned by immersion washing.The metal parts that have not been decomposed can be cleaned by a clean and fine dip silk cloth with cleaning agent (to avoid fiber falling off and sticking to the parts).When cleaning, remove all the grease, dirt, glue, dust etc. 6, non-metallic parts should be imm...