Development history and current situation
Regulator product history can be traced back to the earliest self-operating type regulator, the most original structure is a kind of spherical valve with heavy hammer, using heavy hammer balancing valve core fluid function to adjust. The regulator evolved into using pressure after valve to adjust self-operating regulator.
In the 1930s, the product has already a lot of kinds, the body shape of spherical spherical valve become representative products, after the 1940s, angle valves, butterfly valves, control valve and control valves arise, successively become lead role in markets, all kinds of products have been relatively complete. After the 1960s appeared sleeve valve quickly attention and become the mainstream of the spherical valve products. In the 1970s the new product is CAM torsion valve, its large capacity, simple flow, small unbalanced force, these advantages make it become angle stroke valves outstanding. During this period, all kinds of valve have more perfect and forming series. Meanwhile, side mounted force increased force type regulator (also called Σ F type valve) successfully developed, because of its unique structure, installation height is small, can increase strength, therefore they are popular to factories and customers. From the 1980s, people are also successively manufacture a range of light (or called pure small) regulator, its main characteristic is in pneumatic actuators, using multi-spring instead of single large spring, so pneumatic actuators can appear newly, it makes the regulator miniaturization, high capacity, this kind of actuators can be can replaced old-fashioned heavy actuators. In the 1990s, because intelligent type valve occurrence, turning a new page for the development of the regulator.
Our country pneumatic control valve manufacturing industry started late and relevant factories and department self-designed and produced direct single seat regulator, two seat regulator, 3-way regulating valve, high pressure regulating valves, butterfly valves, long trip actuators and valve positioner and other traditional main product still in use. Our country pneumatic valve leap from 1980s, many factories has introduced advanced foreign technology, improve the performance of existing products, based on further standardization and serialization, have developed lateral mounting type pneumatic control valve and light regulator and other new products.
Our motorized regulator started also relatively late, mid 1950s mainly is modelled Soviet products, create electric contact actuators. In the 1960s began to develop non-contact electric actuators, through 20 years development, now has had a lot of manufacturer specialized in the production of electric regulator, the production of non-contact DKZ type straight trip actuator and DKJ angle stroke electric actuators. In recent 20 years, mainly developed some new products, such as DDZ-Ⅱ and DDZ-Ⅲ model electric actuator. But these products have already arrived renewal, they exist obvious disadvantages, such as big dead zone, small working temperature range (- 10 ~ + 55 ℃), torque protection and performance protection is poor, insulation class is not high. Therefore, currently domestic manufacturers are devoted to product innovations, and design a new type of electric actuators, such as:
① Large power (more than 6000N.m) and small power (less than 100N.m) electric actuators larger power actuators can be applied to large power station and utility plants, metallurgy plant, it uses three phase power as a driving force, equipped with three-phase servo amplifiers, three-phase controllers and three-phase operators, can achieve no disturbances switching, accident alarm and continuous protection. Small power electric actuators are used in small control system.
② Multi-rotating type electric actuators This actuator output shaft maximum circle number is 5~120 circles, mainly used to control high temperature and high pressure regulator, applied for frequent starting and control, adapted to control and remote control, adjusting speed can be fast or slow, under emergency situation can quickly closed or open.
③ High resolution ratio stepping motor actuators stepping motor controller adopts microprocessor control, match with display element, with convenient operation, high control temperature, high stability, low power consumption characteristic, can be used not only in conventional open loop circuit, accept the PC control, and also can be used in closed loop, accept conventional analogue control signal, adapted to various control system requirements.
④ Electric actuators with microcomputer using intelligent servo amplifier instead of traditional analog amplifier, with self diagnosis, self treatment, features revise etc, function. This new terminal control elements are promising, will be introduced detail in chapter 2. At present, the regulator new theory and calculation formula has been accepted by people, but still no unified, history left various formula still be retained. Although using old formula has great error, but calculation is relatively simple; Although using new is precise, but is more trouble, for calculating coefficient is larger, the chart need to consult is also more.
