Characteristics of stainless steel ball valve
不銹鋼球閥閥座主要的密封圈材料是聚四氟乙烯,它對幾乎所有的化學(xué)物質(zhì)都呈惰性,具有摩擦系數(shù)小、性能穩(wěn)定、不易老化、溫度適用范圍廣、密封性能優(yōu)異的綜合特性。但不銹鋼球閥密封所用的PTFE的物理特性,包括膨脹系數(shù)高、對冷流敏感、導(dǎo)熱性差,要求閥座密封的設(shè)計要圍繞這些特性進(jìn)行。
不銹鋼球閥閥座的塑料材料還包括填充聚四氟乙烯、尼龍和許多其他材料。然而,當(dāng)密封材料硬化時,密封的可靠性將被破壞,尤其是在低壓差的情況下。此外,合成橡膠如丁腈橡膠也可用作閥座密封材料,但其適用介質(zhì)和溫度范圍醫(yī)藥有限。另外,如果介質(zhì)沒有潤滑,使用合成橡膠很容易卡死。
不銹鋼球閥結(jié)構(gòu)簡單,一般密封圈是活動的,拆卸更換方便;當(dāng)閥門全開或全關(guān)時,球體和閥座的密封面與介質(zhì)隔離,當(dāng)介質(zhì)通過時,閥門密封面不會被腐蝕,因此適用范圍廣。
所有的固定不銹鋼球閥都有浮動閥座,被介質(zhì)擠壓后移動。密封圈緊緊地壓在球上,以確保密封。通常在球的上下軸上安裝軸承,操作扭矩小,適用于高壓大口徑閥門。但為了降低球閥的工作扭矩,增加密封的可靠性,增加了油封球閥,在密封面之間注入專用潤滑油,形成一層油膜,既增強(qiáng)了密封性能,又降低了密封性能。
其中不銹鋼球閥的維護(hù)步驟如下:
用壓縮空氣吹掃球閥的外表面,檢查并記下球閥上的標(biāo)記,拆卸所有球閥,用煤油清洗零件。
檢查零件缺陷:水壓試驗(yàn)檢查閥體強(qiáng)度;檢查閥座與閥體、關(guān)閉件與密封圈的配合,并進(jìn)行泄漏試驗(yàn);檢查閥桿和閥桿襯套的螺紋磨損情況;檢查件和閥體的密封圈;檢查法蘭的結(jié)合面。
修復(fù)閥體:通過焊接修復(fù)缺陷,更換密封圈或堆焊密封面;對閥體和新密封圈進(jìn)行泄漏試驗(yàn);修整法蘭結(jié)合面;打磨密封面。
修理零件:焊接缺陷或堆焊密封面;研磨或拋光密封面。
更換無法修復(fù)的零件,重新組裝不銹鋼球閥。對整個不銹鋼球閥進(jìn)行水壓試驗(yàn)。不銹鋼球閥應(yīng)根據(jù)原始記錄進(jìn)行噴漆和標(biāo)記。
我們是不銹鋼球閥的生產(chǎn)廠家,如果大家想要了解更多關(guān)于這方面的內(nèi)容可以聯(lián)系我們。我們可以從不同的方面為大家介紹。
The main sealing ring material of the stainless steel ball valve seat is polytetrafluoroethylene (PTFE), which is inert to almost all chemical substances and possesses comprehensive characteristics such as low friction coefficient, stable performance, resistance to aging, wide temperature range, and excellent sealing performance. However, the physical properties of PTFE used in stainless steel ball valve seals, including high expansion coefficient, sensitivity to cold flow, and poor thermal conductivity, require that the design of the valve seat seal be centered around these characteristics.
The plastic materials for stainless steel ball valve seats also include filled polytetrafluoroethylene (PTFE), nylon, and many other materials. However, when the sealing material hardens, the reliability of the seal will be compromised, especially under low pressure differentials. Additionally, synthetic rubbers such as nitrile rubber can also be used as valve seat sealing materials, but their applicable media and temperature ranges are limited. Furthermore, if the medium is not lubricated, the use of synthetic rubber can easily cause jamming.
Stainless steel ball valves have a simple structure, with the sealing ring typically being removable for easy disassembly and replacement. When the valve is fully opened or closed, the sealing surfaces of the ball and valve seat are isolated from the medium. This ensures that the valve sealing surfaces are not corroded when the medium passes through, making the valve widely applicable.
All fixed stainless steel ball valves have floating seats that move after being squeezed by the medium. The sealing ring is tightly pressed against the ball to ensure sealing. Bearings are usually installed on the upper and lower shafts of the ball, resulting in low operating torque and suitable for high-pressure large-diameter valves. However, in order to reduce the operating torque of the ball valve and increase the reliability of the seal, oil-sealed ball valves have been added. Special lubricating oil is injected between the sealing surfaces to form an oil film, which not only enhances the sealing performance but also reduces the operating torque.
The maintenance steps for stainless steel ball valves are as follows:
Blow the outer surface of the ball valve with compressed air, inspect and record the markings on the ball valve, disassemble all ball valves, and clean the parts with kerosene.
Inspecting part defects: Conduct a hydraulic test to check the strength of the valve body; inspect the fit between the valve seat and the valve body, as well as the fit between the closure and the sealing ring, and perform a leakage test; inspect the thread wear of the valve stem and the valve stem bushing; inspect the sealing rings of the components and the valve body; inspect the joint surface of the flange.
Repair valve body: Repair defects through welding, replace the sealing ring or build up welding the sealing surface; conduct a leakage test on the valve body and the new sealing ring; trim the flange joint surface; polish the sealing surface.
Repair parts: weld defects or build-up welding of sealing surfaces; grind or polish sealing surfaces.
Replace the unrepairable parts and reassemble the stainless steel ball valve. Conduct a hydraulic test on the entire stainless steel ball valve. The stainless steel ball valve should be painted and marked according to the original records.
We are a manufacturer specializing in stainless steel ball valves. If you wish to learn more about this topic, feel free to contact us. We can provide an introduction from various perspectives.

