The valve stem bears tension,水電 pressure and torsion forces du路美ring the opening and closing o聽亮f the valve, and is in direct contact w風醫ith the medium. At the same time, t樹業here is relative fricti房日onal movement with the都我 packing. Therefore, whe器海n selecting the valve stem mater多服ial, it must be ensur日場ed that it is in the specified It has 都了sufficient strength, good impact tough商謝ness, abrasion resistance and corrosio志短n resistance at a temperature below拿門 the temperature.
There should be an a高坐nti-static mechanism at the junct服近ion of the valve stem an姐見d the ball and the contact between th爸畫e valve stem and the valv到影e body to prevent static electricity f花很rom accumulating on the ball的可. The safety design o廠綠f the valve stem should prevent it fr車草om being "blowed out" un個麗der working pressure. The a視湖nti-blow-out flange on the va森廠lve stem should be treated with 業愛an annular ring to reduce th笑體e coefficient of friction爸藍.

Characteristics of tr鐵分aditional valve stem p銀子rocessing technology近銀
1.Traditional valve stem thread uses sp讀年iral flying knife, and the thread ac懂機curacy is not accurate; while using tra弟有ditional chipless thread rolli舊爸ng, it is easy to be deformed and tw拿訊isted.
2. The precision of the grinder黑制 used for the polished rod part i司個s not high and it takes a long time.
3. The inverted part adopts two clamps舊都 and turns to pull down and seal,頻技 the concentricity is poor, 數討and the inverted seal是去 is easy to leak.
4. The end part is inde討業xed by the indexing plate of a mil西請ling machine, which is 南草slow in processing, many玩哥 processes and time-consuming.

The characteristics of the new valv綠跳e stem manufacturing不風 process
1.The thread of the new valve stem ad秒小opts self-made extru子妹sion, which has high th匠信read strength and accurate錯腦 precision.
2. The concentricity 行通of the threaded part and the po司女lished rod part overcomes the long-st可呢anding problems of easy distortion and 熱冷easy damage to the thread rolling die哥但 in the domestic thread rolling proce制跳ss.
3. The precision of the polish習物ed rod part reaches the mirror e雨一ffect, the opening and closing are話舞 easy, and the sealing is good算看.
4. The inverted part is formed by C化藍NC technology at one time, with 微黃high accuracy and good inverted s明錯ealing performance.
5.The T-slot at the end part美歌 adopts forging forming proc一河ess, which has high effic光一iency and low cost.
6. The whole set of valve stem produ城懂ction technology has reached the int嗎新ernational advanced level. Un空海der the strong corrosive, volatil有學e and toxic and harmful pro又高cess conditions, once t校討he valve stem seal is damaged, t樹老he highly corrosive, volatile, t劇靜oxic and harmful process medium will友他 leak from the control valve stem 理兵If it comes out, it will bring serious 喝行consequences to the surrounding民都 environment and personal safety. The公章 use of bellows valve我遠 stem seal is a way to solve the ab微呢ove problems. Bellows ar訊機e generally made of stainless st兵媽eel. This special bonnet structure prot議服ects the stuffing box of the 笑他control valve from conta爸請ct with fluid. Once the bellows ruptu和制re, the stuffing box structure abov會市e the bellows will prevent the serious 歌老consequences of the failure of the bel算去lows. In engineering pra路遠ctice, the selection of the be懂時llows seal should fully藍唱 consider that the pressure rati月快ng of the bellows seal will 兵科decrease with the increase 音司in temperature, there should b靜歌e no solid particles in the flui鄉明d, and the longest cy兵理cle life of the bellow舞什s material, etc. . In技街 places where the stai還離nless steel is not resistant to co車術rrosion by certain process media, such著商 as wet chlorine gas, the sma文街ll amount of hydrochloric ac時很id contained in the wet chlorine g科件as will quickly corrode t日見he stainless steel bellows.