Dervos, not only do business with clients, we also make friends with our clients. Every year, one of our biggest clients from Argentina will come to visit us. We work with each other happily, at the same time we enjoy leisure time together. T is the first big client of Dervos in the past ten years. This friendship has been lasting for 10 years. We will keep it to another 10 years. Hope you could be our next best friends.

A seal device that prevents the medium from leaking into the stuffing box when the valve is fully open is referred to as backseat. When the gate valve, the globe valve and the throttle valve are in the closed state, there is no or little pressure in the body cavity, thus the pressure on stem packing is small. When it is opened, the packing is subjected to the working pressure. If there is backseat structure, the working medium pressure can be prevented from acting on the sealing packing, and the life of the sealing packing can be prolonged, so that the valve does not have an external leakage. Another function is that when there is leakage at the sealing packing, the valve can be fully opened to seal the upper sealing portion, so that the packing gland or the packing sleeve can be loosened to replace packing. Therefore, the upper sealing device is required for the gate valve, the globe valve and the throttle valve.

On July 8 th, three of our clients from Malaysia visited us. We arrived at Wenzhou branch on July 9th, and introduced our company to help them better understand Dervos. After introduction, we started business talk to communicate the point they care about and the details we need to pay more attention in the future. In the afternoon, we visited factories of forging and casting gate, globe, check valves and ball valves. In this way, clients can know much more about our products. Lastly we had traditional Chinese food together. This trip is quiet big step between clients and us to cooperate closely in the future. Welcome to China and welcome to Dervos!!

Butterfly valve is one of the most frequently used valves, which we commonly comes with concentric soft seal butterfly valve, double eccentric butterfly valve and triple eccentric butterfly valve. Usually, the concentric soft seal butterfly valve is mainly used in normal temperature, low pressure working conditions, such as water supply and drainage, water conservancy engineering, municipal construction and other fields.Then  what is double eccentric butterfly valve? What is triple eccentric butterfly valve? And what conditions do they apply to? Double Eccentric Butterfly Valve PTFE seated double eccentric butterfly valve is Corrosion resistant. Metal seated double eccentric butterfly valve is high temperature resistance. But metal seated double eccentric butterfly valve is not able to withstand high pressure. AS the plate is directly contact with the sealing face which will cause leakage when used in high pressure working conditions. Double eccentric butterfly valve is used in water supply and drainage, sewage, construction, petroleum, chemical industry, light textile, papermaking, hydropower, metallurgy, energy and other fields. Triple Eccentric Butterfly Valve Triple Eccentric Butterfly Valve makes the best of both concentric and double eccentric butterfly valves.There are more choices for the seat material of triple eccentric butterfly valves, and is able to suit both low and high temperature and All kinds of acid, alkali and other corrosive media. In addition,  triple eccentric butterfly valve can achieve zero leakage, especially suitable for large diameter valve, and, in the use of shut-off valve, can replace the gate valve and ball valve. When used to regulate the flow rate, it can replace the cumbersome globe valve. At present, the triple eccentric butterfly valve is widely  used in oil mining, oil refining, petrochemical, energy generation and other important industrial fields of the pipelines. With people's continuous research,it is believed that the triple eccentric butterfly valve will be used in more and more fields.

Last Friday on July 22nd, Dervos Mid-Year Meeting 2019 was held in Xiamen Office. Our colleagues in Wenzhou office joined us through audio conference. During the meeting, all departments are supposed to do a summary of the first half year and make a plan for next six months. One interesting point mentioned by the logistic department is that railway transportation has a substantial growth in 2019, since a lot of orders in Europe will be delivered by train due to its lower cost. QC department listed out those suppliers with a good quality performance and cooperation attitude. For those, we can have a deeper cooperation in the next half year. Meanwhile, some of the suppliers are not recommended after first cooperation. Purchasing department made a conclusion of on-time delivery for the first six months. Regarding the weekly status follow up and report, there is something we can do to achieve better on-time delivery. Last month, the whole Dervos sales department is divided into two groups. Two managers of these two newly established sales groups reported separately our sales performance and set a new goal for the next half year. Thanks to this company restructuring, both groups are more inspired to compete and fight for the same goal-better sales performance. Our sales director Ken brought us the good news that our sales amount has exceed the same period of last year. Finally, our big boss Eric made a conclusion for this meeting, reviewing the important achievements we have made. Also, we have big plan for the next six months- to set up finished product center and to visit our clients abroad. Although we have gone through a lot of pain and hardships during the company reforming and development in this half year, we still hold the belief that all the efforts we made will pay off one day. We are always on the way to provide Dervos clients with better customer service and products.

The butterfly valve, also known as the flap valve, is a simple regulating and isolation valve. The closing member (valve or disc) is a disc that rotates around the valve shaft to achieve opening and closing. From the structure of valve, butterfly valves can be classified into concentric butterfly valve, double offset butterfly valve, and triple offset butterfly. For concentric type, the center of the stem is on the center line of the valve body and passes through the center of the sealing surface section. For double eccentric type, the stem center forms a deviation from the valve seal section and deviates from the valve body centerline. For triple eccentric butterfly valve, the third eccentric is valve body center forms an angular deviation from the center of the valve body sealing surface. From the connection type of butterfly valve, there wafer butterfly valve, lug butterfly valve, flanged butterfly valve and butt-weld butterfly valve. For wafer type, there are two or more center holes to help with valve installation. For lug type, the around bolted holes make lug type a safer choice compared to wafer type. The double flanged butterfly valve are often used for large-size butterfly valves. The butt welded butterfly vale are used in high pressure application. From the seat type, we have soft seat butterfly valve and metal seat butterfly valve. Generally speaking, concentric butterfly valve and double offset butterfly valve own soft sealing. While, the triple offset butterfly valve has metal-to metal seat.