The sealing of the valve is one of the important factors of the quality performance of the valve, especially the imported valve , which has higher requirements on the sealing performance of the valve. Take the representative imported valve brand German Lite LIT as an example, all the switch types of this brand Valves are required to have zero leakage when closed, including internal leakage and external leakage. The important factors influencing the performance of the sealing performance are the valve sealing ring and the material of the valve sealing ring. We combine the characteristics of the German LIT product. Analysis of the characteristics and selection of imported valve seal materials According to the product brochure of the German LIT LIT , the definition of the sealing ring: the annular ring consisting of one or several parts, fixed on one ring or washer of the bearing and in contact with or forming with another ring or washer. A narrow labyrinth gap prevents leakage of media and foreign objects. In the sealing ring of the valve, the sealing ring is a ring with a circular cross section, and because it has an O -shaped cross section , it is called an O -ring. Valve seal materials are available in both metal and non-metal categories. Common materials and their use conditions are as follows: 1 , synthetic rubber 2 , nylon 3 , PTFE 4 , cast iron 5 , Babbitt alloy 6 , copper alloy 7 , chrome stainless steel 8 , chrome nickel titanium stainless steel 9 , nitriding steel 10 , boronizing Introduction:
3.Color:Pure white/Normal white
4.Nutrition Organic White Garlic,Silver White Garlic,Organic White Garlic Seed,Organic White Garlic Powder shandong changrong international trade co.,ltd. , https://www.changronggarliccn.com
Synthetic rubber is superior to natural rubber in its oil resistance, temperature resistance and corrosion resistance. General synthetic rubber temperature t ≤ 150 ℃, natural rubber t ≤ 60 ℃, nominal pressure PN ≤ 1MPa rubber for importing soft seal globe valve, soft sealing valve, diaphragm valve inlet, inlet valve soft seal, inlet check valve sealing valves, pinch valves and the like.
Nylon has the characteristics of small friction coefficient and good corrosion resistance. Nylon is mostly used for imported ball valves and inlet shut-off valves with temperature t ≤ 90 °C and nominal pressure PN ≤ 32 MPa .
Polytetrafluoroethylene temperature for t ≤ 232 ℃, nominal pressure PN ≤ 6.4MPa inlet shut-off valve, inlet valve, the soft sealing ball valve inlet. This is a soft seal O -ring commonly used by German Litzui .
Cast iron is used for gate valves, globe valves and plug valves for temperatures t ≤ 100 °C, nominal pressure PN ≤ 1.6MPa , gas and oil.
Babbitt alloy is used for ammonia shut-off valves with a temperature t -70~150 °C and a nominal pressure PN ≤ 2.5MPa .
Common materials for copper alloys are 6-6-3 tin bronze and 58-2-2 manganese brass. Copper alloy has good wear resistance and is suitable for water and steam with temperature t ≤ 200 °C and nominal pressure PN ≤ 1.6MPa . It is commonly used for gate valves, globe valves, check valves, plug valves, etc.
The commonly used grades of chrome stainless steel are 2Cr13 and 3Cr13 which are quenched and tempered and have good corrosion resistance. It is commonly used on valves of water, steam and petroleum media with temperature t ≤ 450 °C and nominal pressure PN ≤ 32 MPa . This is also the seal ring commonly used by the German hard LIT 's hard seal valve.
The common grade of chrome-nickel-titanium stainless steel is 1Cr18Ni9ti , which has good corrosion resistance, erosion resistance and heat resistance. It is suitable for mediums such as steam and nitric acid with temperature t ≤ 600 °C and nominal pressure PN ≤ 6.4 MPa , for shut-off valves, ball valves, etc.
The commonly used grade of nitriding steel is 38CrMoAlA , which has good corrosion resistance and scratch resistance after carburizing treatment. Commonly used for power station gate valves with temperature t ≤ 540 °C and nominal pressure PN ≤ 10MPa .
Boronizing is directly processed from the valve body or the valve body material to the sealing surface, and then the boronizing surface treatment is performed, and the sealing surface has good wear resistance. Used for power station drain valve.
Our farmland has fertile soil,sufficient sun-light,ample rainfall,and far away from urban pollution,traditional planting methods,artificial weeding,standardized pesticide residues.
Our pure White Garlic,keep freshness and nutrition to the greatest extent
With the advantages of good condition,pure flavor,strong aroma,high allicin etc.
More knowledge:
The bulb of garlic,an allium plant in the lily family.with the pungent flavor and spicy taste.spherical shape with a diameter of 3-6.5cm. The surface is covered with white and papery-skin.
The top is slightly pointed, with residual scape in the middle,many fibrous root marks at the base. The bulbous valve is slightly ovoid, with a membranous outer skin, slightly pointed at the apex, and an arcuate bulge on one side.
Specification:
1.Brand:Changrong
2.Variety:Liliaceous Vegetables
Manganese: 2% of the Daily Value
Vitamin C: 1% of the Daily Value
Selenium: 1% of the Daily Value
Fiber: 0.06 grams
Decent amounts of calcium, copper, potassium, phosphorus, iron and vitamin B1