Here are seven main advantages of insulated ball valve as follows. 1. The fluid resistance is small, and its resistance coefficient is equal to that of the tubulation of the same length. 2. It has simple structure, small volume and light weight. 3. It is compact and reliable. At present, plastic materials with good sealing performance is preferred as the sealing surface materials of ball valve. Materials like this also have been widely used in the vacuum system. 4. It is easy to be operated, to be opened and closed quickly. The angle from opening it to closing it is just only 90 °, which is advantageous for remote control. 5. It is maintained easily. The structure of ball valve is very simple and the sealing ring is removable. Therefore, it is more convenient that it can be changed and disassembled. 6. If the insulted ball valve is fully opened or fully closed, the sealing surface can not be eroded when the medium is flow through it. This is because the ball valve body and seat sealing surface are isolated from the medium. 7. The applicable scope is wide. The length range of diameter is from several millimeters to a few meters. It can be applied from high vacuum to high pressure. If the ball body rotates 90 degrees, the sphere can be showed completely in the inlet and outlet so as to block the flow. Insulated ball valve is a relatively new type among ball valve types. The structure has its own superiority, for example the switch is frictionless, the sealing surface is not easy to wear and the open-close torque is small. Then, the specifications of the actuator can be smaller. If it works with multi-turn electric actuators, the medium can be adjusted and cut off. It is widely used in demanding strictly cutting-off operation conditions in petroleum, chemical industry, urban water supply and drainage, etc.

Here are some main brief installation points of spring relief valve or spring safety valve we need to notice. Before installing spring relief valve, the first thing we need to pay attention to is to be sure to test the seal performance. If the relief valve leaks or the air cushion is broken, they are needed to be changed immediately accordingly. Then, it can be got the best use by all of us. The first premise is that the vertical installation is needed to be paid attention to for all parts of the relief valve in the process of relief valve installation. And, the installation angle should be precise and formal. Of course, tools should be used to make the corresponding auxiliary. Then, it can make the whole installation process smoothly and effectively. Second, it should be noticed that it is not allowed to give pressure on the exit of the relief valve during the installation of relief valve. It’s better to let it empty directly so that the relief valve can work effectively. Then, people can get it best effect, have better use experience and install the relief valve in place. Third, it should be noticed that the operator had better wear the corresponding gloves tools on their hands to avoid that oil pollute relief valve. The oil pollution can affect the sealing effect of relief valve. At same time, it also may lose the whole service life of the relief valve. Therefore, it is a good way to let the operator wear the gloves tools.

Gate valves are the main components of the oil (gas) wellhead, several kinds of the common faults in the use of the common faults as follows. 1. Leakage between gate valve and gate valve junction First, check whether valve and gate valve connecting bolts are tight or not, if not tighten, its seal ring and the flange seal groove surface if not sufficiently connected, often lead to leakage. Check bolt and nut orderly, tighten all bolts, until the compress seal ring. Second, check the size and accuracy of the surface of the seal ring and the flange seal groove, if the sealing contact surface has wrong size or too rough, to repair or update it. Also check whether the contact surface of seal ring and the flange seal groove exist a little bit erosion, sand hole, sand holes, or impurities, or other defects, if any, should carry on the corresponding welding, repair, or cleaning up. 2. Leakage from bonnet Bonnet leakage, this failure phenomenon often occurs in the leakage of packing seal. First, check seal if fitting is correct, whether it is suitable for seal groove, if there is such a problem, replace the sealing ring or repair the seal groove. Second, check if seals have burrs, fracturing, and twist off, if any, replace the seals. Then, check if the surface of sealing groove seal is rough or have other defects, if there is a defect, eliminate the defects or update the damaged parts. Bonnet or scaffolds by compression seal packing, should check the installation of the packing case, if find packing installed upside down, should remove, carry out in accordance with the correct way to install. Pay special attention to the surface of packing seal joint. Finally, check if the precision of the contact surface of seal fittings meet the requirements. 3. Leakage from valve body cavity In the process of casting, sometimes valve body may appear casting defects, such as sand holes, sand hole. Although it is difficult to find in the process of machining, once the pressure put on the valve body, hidden casting defects will be exposed. If there is this kind of situation, welding, repairing or updating it. 4. Leakage from valve seat and valve plate Leakage occurs in valve seat and plate, which is the most common phenomenon among the installation or maintenance of gate valves. Generally this can be divided into two kinds: one is leaking in seal surface; the other is leaking in seal root. Above all, check the seat and the precision of the sealing contact surface of valve plate. The sealing surface needs grinding, if there is rough surface, remove and grind it again. Second, check whether there are pitting, indentation, sand holes, cracks and other defects the sealing surface, if in this case, replace valve seat and valve plate. For the valve seat with compression spring, should check whether the pressure spring elasticity is conform to the requirements, if less resilient, update the compression spring. Besides, check if T-shape coupling place of valve plate and valve ste...