Needle valve selection principle
1, low temperature medium pipeline system and device, appropriate chooses combined with low temperature type needle valve bonnet.
2, refining unit of catalytic cracking unit of piping system, can choose lifting lever type needle valve.
3, chemical system in acid and alkali corrosive stainless steel hydraulic fitting medium, such as equipment and piping system, appropriate chooses of austenitic stainless steel and ptfe seat sealing type stainless steel needle valve.
4, metallurgy system, power system, petrochemical plant, city heating system in high temperature medium pipeline system or device, can choose a metal to metal seal type needle valve.
5, the need for flow control, can choose the worm gear and worm drive, pneumatic or electric type with v-shaped opening adjust needle valve.
6, oil, natural gas transportation director line, need cleaning the pipeline, and to be buried in the ground, with full size, full welded structure type needle valve; Buried in the ground, choose stainless steel tube fitting the full size welded ball valve connection or flange connection. 7, product oil pipeline and storage equipment, choose the type needle valve with flange connection.
8, city gas and natural gas pipelines, selection of flange connection and female connection type needle valve.
9, metallurgy system oxygen in the pipeline system, appropriate chooses strict degreasing process, flange connection type needle valve.
Type stainless steel needle valve is whole USES the high quality 304316321201 stainless steel forging process materials and other materials processing production of needle valve, brass is made by a brass alloy casting process of needle valve.
Stainless steel material has corrosion resistance, abrasion resistance, resistance to high pressure, high temperature resistance, oxidation resistance and high cleanness many advantages, and brass or copper materials do not have the advantages of resistance to high pressure, high temperature resistance, abrasion resistance, relative to the stainless steel needle valve as many, the scope of use type stainless steel needle valve is widely used. Type stainless steel needle valve and instrumentation valve body and internal parts are all materials with solid or forging bar solid body directly, high density, tensile performance is strong, adopts CNC stainless steel needle valve precision machining, precision degree is high, good seal. Brass type needle valve, and the process for forging brass instrument valve casting body, low tensile performance, corrosion resistance is poor, not suitable for high temperature and high pressure, bad working conditions such as wear-resisting, only suitable for use in water heating, air conditioning and other devices.
Brass type needle valve and instrument varieties such as ball valves also is less, because of pressure on the sex is not enough, so are generally low class product.
In respect of structure, the stainless steel needle valve body etc are larger and brass pin type valve, because the stainless steel needle valve type generally use temperature is higher, the pressure is high, so in the central stuffing box design that is done is higher, in case of leakage with the rising of middle pressure and temperature. And brass type needle valve structure is simple, do not need to do is too high, of central working conditions for the use of pressure and temperature are relatively low. Type of valve and brass and stainless steel needle valve type of production cost is large, so the price of the stainless steel needle valve type is relatively higher, and the brass type needle valve price is relatively cheap.
Our News
