閥門經過長期使用后，閥瓣和閥座的密封面會發生磨損，嚴密性降低。修復密封面是一項量大且十分重要的工作，修復的主要方法是研磨，對磨損嚴重的密封面，是先堆焊經車削加工后再研磨。閥門的研磨包括：清洗和檢查過程；研磨過程；檢驗過程。

　　After long-term use, the sealing surfaces of the valve disc and seat will wear and the tightness will decrease. Repairing the sealing surface is a large and very important task, and the main method of repair is grinding. For severely worn sealing surfaces, it is first welded and turned before grinding. The grinding of valves includes: cleaning and inspection processes; Grinding process; Inspection process.

　　1、清洗和檢查過程清洗密封面在油盤內，使用專業清洗劑，邊洗邊檢查密封面的損壞情況。用肉眼難以確定的細微裂紋可用著色探傷法進行。

　　1. Cleaning and inspection process: Clean the sealing surface in the oil pan, use professional cleaning agents, and inspect the damage of the sealing surface while washing. Minor cracks that are difficult to determine with the naked eye can be detected by dye penetrant testing.

　　經過清洗后，應檢查閥瓣或閘閥與閥座密封面的密合情況，檢查時用紅色和鉛筆。用紅丹試紅，檢查密封面印影，確定密封面密合情況；或用鉛筆在閥瓣和閥座密封面上劃幾道同心圓，然后將閥瓣與閥座密合旋轉，檢查鉛筆圓圈擦掉情況，確定密封面的密合。如果密合不好，可用標準平板分別檢驗閥瓣或閘板密封面和閥體密封面，確定研磨部位。

　　After cleaning, the sealing surface between the valve disc or gate valve and the valve seat should be checked for tightness using red and pencil. Use red lead to test for redness, check the seal imprint on the sealing surface, and determine the sealing condition of the sealing surface; Or use a pencil to draw several concentric circles on the sealing surface of the valve disc and valve seat, then rotate the valve disc and valve seat tightly, check the wiping off of the pencil circle, and determine the sealing surface tightness. If the sealing is not good, a standard flat plate can be used to inspect the sealing surface of the valve disc or gate and the sealing surface of the valve body separately to determine the grinding area.

　　2、研磨過程研磨過程實質上是不用車床的切削過程，閥頭或閥座上的麻點或小孔深度一般都在0.5mm以內，可以采用研磨的方法進行檢修。研磨過程分為粗磨、中磨和細磨。

　　2. The grinding process is essentially a cutting process without the use of a lathe. The depth of the pits or small holes on the valve head or seat is generally within 0.5mm, and can be repaired by grinding. The grinding process is divided into coarse grinding, medium grinding, and fine grinding.

　　粗磨是為了消除密封面上的擦傷、壓痕、蝕點等缺陷，使密封面得到較高平整度和一定的光潔度，為密封面的中磨打下基礎。粗磨利用研磨頭或研磨座工具，采用粗粒砂紙或粗粒研磨膏，其粒度80#-280#，粒度粗，切削量大，效率高，但切削紋路較深，密封面表面較粗糙。因此，粗磨只要平整地把閥頭或閥座的麻點去掉即可。中磨是為了消除密封面上的粗紋路，進一步提高密封面的平整度和光潔度。采用細粒砂紙或細粒研磨膏，其粒度為280#-W5，粒度細，切削量小，有利于降低粗糙度；同時應更換相應的研具，研具應清潔干凈。中磨完后，閥門的接觸平面應達到光亮。如用鉛筆在閥頭或閥座上劃幾道，將閥頭或閥座對著輕轉一圈，應把鉛筆線抹去。細磨是閥門研磨的后一道工序，主要是提高密封面的光潔度。細磨時可用W5或更細的微份與機油、煤油等稀釋后，用閥門的閥頭對著閥門的閥座進行研磨，而不用演劇，這樣更有利于密封面的密合。研磨時一般順時針方向轉60-100°左右，再反方向轉40-90°左右，輕輕地磨一會兒，必須檢查一次，待磨得發亮發光，并在閥頭和閥座上可以看到一圈很細的線，顏色達到黑亮黑亮的時候，再用機油輕輕地磨幾次，用干凈的紗布擦干凈即可。研磨完以后，再把其他缺陷消除，即應盡快地組裝，以免破壞一磨好的閥頭。手工研磨不管粗研還是細研，均是始終貫穿提起、放下；旋轉、往復；輕敲、換向等操作相結合的研磨過程。其目的是為了避免磨粒軌跡重復，使研具和密封面得到均勻的磨削，提高密封面的平整度和光潔度。

　　Rough grinding is used to eliminate defects such as scratches, indentations, and corrosion points on the sealing surface, resulting in higher flatness and a certain degree of smoothness, laying the foundation for intermediate grinding of the sealing surface. Coarse grinding uses a grinding head or grinding seat tool, using coarse-grained sandpaper or coarse-grained grinding paste, with a particle size of 80 # -280 #, coarse particle size, large cutting amount, high efficiency, but deep cutting patterns and rough sealing surface. Therefore, rough grinding only needs to remove the rough spots on the valve head or seat smoothly. Medium grinding is used to eliminate rough patterns on the sealing surface, further improving the flatness and smoothness of the sealing surface. Using fine-grained sandpaper or fine-grained grinding paste, with a particle size of 280 # - W5, fine particle size, small cutting amount, which is conducive to reducing roughness; At the same time, the corresponding research tool should be replaced and cleaned thoroughly. After grinding, the contact surface of the valve should reach a bright state. If you use a pencil to make a few lines on the valve head or valve seat, turn the valve head or valve seat lightly and wipe off the pencil line. Fine grinding is the next process after valve grinding, mainly to improve the smoothness of the sealing surface. When grinding finely, W5 or finer particles can be diluted with engine oil, kerosene, etc., and then the valve head of the valve can be used to grind against the valve seat of the valve, without the need for drama, which is more conducive to the sealing surface. When grinding, it is generally turned clockwise by about 60-100 ° and then counterclockwise by about 40-90 °. Gently grind for a while, and it must be checked once. When the grinding is bright and shiny, a circle of very thin lines can be seen on the valve head and seat. When the color reaches black and shiny, gently grind it several times with engine oil and wipe it clean with clean gauze. After grinding, other defects should be eliminated and assembled as soon as possible to avoid damaging the polished valve head. Manual grinding, whether coarse or fine, always involves lifting and lowering throughout the process; Rotation and reciprocating; The grinding process that combines tapping, reversing, and other operations. The purpose is to avoid repeated abrasive trajectories, achieve uniform grinding of the grinding tool and sealing surface, and improve the flatness and smoothness of the sealing surface.

　　3、檢驗階段在研磨過程中始終貫穿著檢驗階段，其目的是為了隨時掌握研磨情況，做到心中有數，使研磨質量達到技術要求。應該注意的是，不同的閥門研磨時應使用適應各種密封面形式的研磨工具，以提高研磨效率，保證研磨質量。

　　3. The inspection stage runs through the grinding process, with the purpose of keeping track of the grinding situation at all times, achieving a clear understanding, and ensuring that the grinding quality meets the technical requirements. It should be noted that grinding tools suitable for various sealing surface forms should be used when grinding different valves to improve grinding efficiency and ensure grinding quality.

　　閥門研磨時一項很細致的工作，需要在實踐中不斷的體會、摸索、提高，有時研磨得很好，可是裝上以后還是漏汽漏水，這是因為在研磨過程中有磨偏的想象，手拿研磨桿不垂直、歪斜，或是研具尺寸角度有偏差所致。由于研磨劑是磨料和研磨液組成的一種混合劑，而研磨液又僅是一般的煤油和機油。因此，正確地選用研磨劑關鍵的一環是正確地選用磨料。

　　Valve grinding is a very meticulous task that requires continuous experience, exploration, and improvement in practice. Sometimes the grinding is done well, but after installation, there is still steam and water leakage. This is because there is an imagination of grinding deviation during the grinding process, such as the grinding rod not being vertical or skewed, or the size and angle of the grinding tool being deviated. Due to the fact that abrasives are a mixture of abrasives and grinding fluids, and grinding fluids are only ordinary kerosene and engine oil. Therefore, the key to selecting abrasives correctly is to choose the right abrasive.

　　4、如何正確地選閥門研磨劑？氧化鋁（AL2O3） 氧化鋁又稱剛玉，其硬度較高，使用很普遍。一般用來研磨鑄鐵、銅、鋼及不銹鋼等材料的工件。

　　4. How to choose valve grinding agent correctly? Aluminum oxide (AL2O3), also known as corundum, has high hardness and is widely used. Generally used for grinding workpieces made of materials such as cast iron, copper, steel, and stainless steel.

　　碳化硅（SiC） 碳化硅有綠色及黑色兩種，其硬度比氧化鋁高。綠色碳化硅適用于研磨硬質合金；黑色碳化硅用于研磨脆性材料及軟材料的工件，如鑄鐵、黃銅等。碳化硼（B4C） 硬度僅次于金剛石粉末而比碳化硅硬，主要用來代替金剛石粉末研磨硬質合金，研磨鍍硬鉻的表面。氧化鉻（Cr2O3） 氧化鉻是一種硬度高和極細的磨料，淬硬鋼精研時常常使用氧化鉻，一般也用它來拋光。氧化鐵（Fe2O3） 氧化鐵亦是一種極細的閥門磨料，但硬度及研磨效果均較氧化鉻差，用途與氧化鉻相同。金剛石粉末 即結晶磮C，它是硬的磨料，切削性能較好，特別適用于研磨硬質合金。此外，磨料粒度（磨料的顆粒尺寸大小）的粗細對研磨效率及研后表面粗糙度有顯著的影響。粗研時，閥門工件表面粗糙度要求不高，為提高研磨效率宜選用粗粒度的磨料；精研時研磨余量小，工件表面粗糙度的要求高，可采用細粒度的磨料。密封面粗研時磨料的粒度一般為120＃～240＃；精研為W40～14。?閥門調制研磨劑，通常是往磨料里直接加入煤油和機油。用1/3煤油加2/3機油與磨料調合成的研磨劑適用于粗研；用2/3的煤油加1/3機油與磨料調合成的研磨劑可用于精研。當研磨硬度較高的工件時，使用上述研磨劑的效果就不夠理想。這時，可采用三份磨料加一份加熱的豬油調合起來，冷卻后形成糊狀，使用時再適當加些煤油或汽油調勻。

　　Silicon carbide (SiC) comes in two types: green and black, and its hardness is higher than that of aluminum oxide. Green silicon carbide is suitable for grinding hard alloys; Black silicon carbide is used for grinding brittle and soft materials such as cast iron, brass, etc. Boron carbide (B4C) has a hardness second only to diamond powder and harder than silicon carbide. It is mainly used to replace diamond powder in grinding hard alloys and grinding surfaces coated with hard chromium. Chromium oxide (Cr2O3) is a high hardness and extremely fine abrasive commonly used for precision grinding of quenched and hardened steel, and is also commonly used for polishing. Iron oxide (Fe2O3) is also an extremely fine valve abrasive, but its hardness and grinding effect are inferior to chromium oxide, and its use is the same as chromium oxide. Diamond powder, also known as crystalline carbide, is a hard abrasive with good cutting performance, especially suitable for grinding hard alloys. In addition, the grain size of the abrasive has a significant impact on the grinding efficiency and surface roughness after grinding. During rough grinding, the surface roughness of the valve workpiece is not required to be high. To improve grinding efficiency, it is advisable to use coarse-grained abrasives; During precision grinding, the grinding allowance is small and the surface roughness of the workpiece is required to be high. Fine grained abrasives can be used. The abrasive particle size during rough grinding of the sealing surface is generally between 120 # and 240 #; Refined to W40-14.? Valve modulation grinding agent usually involves directly adding kerosene and engine oil to the abrasive. The abrasive prepared by mixing 1/3 kerosene with 2/3 engine oil and abrasive is suitable for rough grinding; A grinding agent prepared by mixing 2/3 kerosene with 1/3 engine oil and abrasive can be used for precision grinding. When grinding workpieces with high hardness, the effect of using the above-mentioned abrasives is not ideal. At this point, three parts of abrasive and one part of heated lard can be mixed together to form a paste after cooling. When using, some kerosene or gasoline can be added appropriately and mixed evenly.

　　5、研磨工具的選擇閥瓣和閥座密封面由于損壞程度不同，不能直接對研，而是先用事先專做的一定數量和規格的假閥瓣（即研磨頭）、假閥座（即研磨座）分別對閥座、閥瓣進行研磨。研磨頭和研磨座用普通碳素鋼或鑄鐵制做，尺寸和角度應與置于閥門上的閥瓣、閥座相等。研磨若手工進行，需配置各種研磨桿。研磨桿和研具要裝配得當，不能歪斜。為減輕人的勞動強度，加快研磨速度，常采用電動研磨機或振動研磨機研磨。

　　5. The selection of grinding tools for valve discs and valve seat sealing surfaces cannot be directly ground due to different degrees of damage. Instead, a certain number and specifications of pre made fake valve discs (i.e. grinding heads) and fake valve seats (i.e. grinding seats) are used to grind the valve seat and valve disc respectively. The grinding head and grinding seat are made of ordinary carbon steel or cast iron, and the size and angle should be equal to the valve disc and seat placed on the valve. If grinding is done manually, various grinding rods need to be configured. The grinding rod and grinding tool should be assembled properly and not tilted. To reduce human labor intensity and accelerate grinding speed, electric grinding machines or vibration grinding machines are often used for grinding.