Wenzhou Zhibo Mechanical Technology Co., Ltd. is a production oriented enterprise that integrates research and development, manufacturing of vacuum systems, biopharmaceuticals, and food. Its products are mainly used in the fields of semiconductor biopharmaceuticals and food.
The company implements ISO9001:2008 quality management system certification and has mature precision machining capabilities, surface treatment technology, and quality assurance system. The diversity and diversity of products can provide customers with a range of complete services.
The company team is based on quality and integrity, continuously absorbing new technological achievements, improving design and production, and providing high-quality system accessories and after-sales service to global customers through the company's professional market management and sales team.
A valve is a device used to control fluid flow, pressure, and direction. The controlled fluid can be liquid, gas,gas liquid mixture, or solid liquid mixture. Valves are usually composed of valve bodies, valve covers, valve seats, opening and closing components, driving mechanisms, seals, and fasteners. The control function of valves relies on the driving mechanism or fluid to drive the lifting, sliding, swinging, or rotary motion of the opening and closing components to change the size of the flow channel area. Valves have a wide range of uses and are closely related to people's daily lives. For example, faucets used in water pipes and pressure reducing valves used in liquefied petroleum gas stoves are all valves. Valves are also indispensable components in various mechanical equipment such as internal combustion engines, steam engines, compressors, pumps, pneumatic transmission devices, hydraulic transmission devices, vehicles, ships, and aircraft. Two thousand years ago, Chinese people used bamboo pipes and wooden plug valves on water pipelines, and later used water gates on irrigation channels. Plate check valves were used on smelting air boxes, and bamboo pipes and plate check valves were used in well salt mining to extract salt water. With the development of smelting technology and hydraulic machinery, copper and lead plug valves emerged in Europe. With the use of boilers, lever heavy hammer safety valves appeared again in 1681. Before the appearance of the Watt steam engine in 1769, plug valves and check valves had always been the main valves. The invention of the steam engine brought valves into the field of mechanical industry. In addition to using plug valves, safety valves, and check valves, butterfly valves are also used in Watt's steam engine to regulate flow. With the increase of steam flow rate and pressure, using a plug valve to control the inlet and outlet of the steam engine can no longer meet the needs, resulting in the appearance of a slide valve.
Around 1840, globe valves with threaded stems and wedge gate valves with trapezoidal threaded stems emerged successively, which was a major breakthrough in the development of valves. The emergence of these two types of valves not only met the requirements of various industries at that time for continuously increasing pressure and temperature, but also preliminarily met the requirements for flow regulation. Subsequently, with the development of the power industry, petroleum industry, chemical industry, and shipbuilding industry, various high and medium pressure valves have rapidly developed.
After World War II, due to the development of polymer materials, lubricating materials, stainless steel, and cobalt based hard alloys, ancient plug valves and butterfly valves gained new applications, while ball valves and diaphragm valves rapidly developed. The variety of globe valves, gate valves, and other valves has increased, and the quality has improved. The valve manufacturing industry has gradually become an important sector in the mechanical industry. Valves can be divided into six categories based on their usage functions: shut-off valves, regulating valves, check valves, diverter valves, safety valves, and multi-purpose valves.
Block valves are mainly used to cut off fluid paths, including globe valves, gate valves, plug valves, ball valves, butterfly valves, diaphragm valves, clamp valves, etc; Regulating valves are mainly used to regulate the pressure and flow of fluids, including regulating valves, throttle valves, pressure reducing valves, and float control valves; Check valves are used to prevent the reverse flow of fluid; Diverter valves are used to distribute the flow direction of fluids or separate two phase fluids, including slide valves, multi way valves, drain valves, and exhaust valves; Safety valves are mainly used for safety protection to prevent damage to boilers, pressure vessels, or pipelines due to overpressure; A multi purpose valve is a valve that has more than one function, such as a stop check valve, which can act as both a shut-off valve and a check valve.
Industrial pipeline valves can be divided into vacuum valves, low pressure valves, medium pressure valves, high-pressure valves, and ultra high pressure valves according to nominal pressure; Valves can be divided into room temperature valves, medium temperature valves, high temperature valves, and low temperature valves according to their working temperature; Valves can also be classified according to the type of driving device, the connection method with the pipeline, and the material used for the valve body. Valves can be named individually or in combination according to various classification methods, as well as according to the structural characteristics or specific uses of the opening and closing components.
The basic parameters of a valve are working pressure, working temperature, and diameter. For various valves widely used in industrial pipelines, nominal pressure and nominal diameter are commonly used as basic parameters. The nominal pressure refers to the maximum working pressure that a valve made of a certain material is allowed to withstand at a specified temperature. The nominal diameter refers to the nominal inner diameter of the end where the valve body is connected to the pipe.
Valves have different requirements based on their type and purpose, mainly including sealing, strength, regulation, flow, opening and closing performance. When designing and selecting valves, in addition to considering basic parameters and performance, the performance of the fluid should also be considered, including its phase state (gas, liquid or solid particles), corrosiveness, viscosity, toxicity, flammability and explosiveness, rarity, and radioactivity.
Sealing performance and strength performance are fundamental and important properties of all valves. The sealing of valves is divided into two parts: internal sealing and external sealing. Internal sealing is the sealing between the valve disc and the valve seat; External sealing refers to the sealing between the moving part of the valve stem and the valve cover, between the valve body and the valve cover, and between the valve body and the pipeline connection. Valves not only require good sealing performance during use, but also must ensure safety.
If leakage occurs due to poor sealing or parts are damaged due to insufficient strength, it will cause varying degrees of economic losses, such as transporting toxic, flammable, explosive, or highly corrosive fluids, and may also lead to serious safety accidents. In order to ensure the sealing and strength of the valve, in addition to complying with relevant standards and regulations for reasonable structural design and ensuring process quality, it is also necessary to select materials correctly.
Usually, valves for low pressure non corrosive fluids use cast iron or cast copper; Cast steel or forged steel for high and medium pressure valves; High temperature or high pressure valves use alloy steel; Valves used for corrosive fluids are made of stainless steel, plastic, corrosion resistant alloys (such as copper nickel molybdenum alloys, titanium alloys, and lead alloys), or lined with corrosion resistant materials such as cast iron and cast steel.
Usually, the sealing surface of low pressure valves is mostly made of brass or bronze, while high and medium pressure valves are mostly made of stainless steel. High demand high and medium pressure valves or high temperature valves use cobalt based hard alloys. Polymer materials have been widely used in valves, such as the valve seat of ball valves mainly made of polytetrafluoroethylene plastic, and the sealing ring of butterfly valves and the diaphragm of diaphragm valves made of various rubber materials. These materials have better sealing performance than metals within the temperature range that can be used.
With the development of modern nuclear industry, petrochemical industry, electronics industry, and aerospace industry, as well as the development of process automatic control and long distance fluid transportation, the development of modern low temperature valves, vacuum valves, nuclear industry valves, and various regulating valves has been promoted. The application of valve drive devices for remote control and program control is increasing.
The development of future valves will focus on expanding product parameters, developing energy saving, labor saving, and self control valves, improving structures, adopting new materials and processes, increasing the service life of valves, and developing specialized valve series, such as low temperature valves, vacuum valves, nuclear industry valves, safety valves, regulating valves, drain valves, and valve drive devices for liquid oxygen, liquid hydrogen, and liquefied natural gas.