1. Basic knowledge of stainless steel ferrule joints and pipe series products
2. Basics of stainless steel materials
- The full name of stainless steel is stainless acid-resistant steel. It is divided into two categories: stainless steel and acid-resistant steel. Among them, those that can resist atmospheric corrosion are called stainless steel, and those that can resist corrosion by chemical media (such as strong acids, strong alkali) are called acid-resistant steel.
- Stainless steel is divided into austenite, martensite, ferrite, duplex type and precipitation hardening type from the organizational structure. The most commonly used are austenite and martensite.
3. Alloy elements contained in stainless steel
- Stainless steel mainly adds Cr, Ni, Mo and other rare elements to the steel.
- Generally speaking, steel with a chromium content greater than 12% has the characteristics of stainless steel.
4. Why doesn’t stainless steel rust?
-The essence of stainless steel not rusting is that when stainless steel is exposed to air, a passive film quickly forms on the surface, thereby preventing further oxidation.
-The main component of this passivation film is ferrochromium compound (FeCr)2O3. It has strong acid resistance and corrosion resistance.
5. General uses of stainless steel materials
-Austenite is generally used for processing parts and structural parts. Commonly used grades:
-1Cr18Ni9 (302)
-1Cr18Ni9Ti,
-Y1Cr18Ni9 (303)
-0Cr19Ni9 (304)
-0Cr17Ni12Mo2 (316)
-00Cr17Ni14Mo2 (316L)
-Both are austenitic stainless steels.
6. About 302, 303, 304
-What should we choose 302, 303, 304?
? -302 has a maximum carbon content of 0.15%; generally used Used for ordinary tensile parts, decoration, and daily necessities
? -304 The maximum carbon content is 0.08%; generally used for pipes
? -303 The basic composition is the same as 302, but contains The sulfur content is high, reaching 0.15%, and has good cutting performance, which can significantly reduce processing costs. Generally used for machined parts
7. What are the differences between 316 and 316L
-Why are 316 or 316L used for parts and whether they are interchangeable.
? - The main difference is that 316 has a maximum carbon content of 0.08%, and 316L has a maximum carbon content of 0.03%. When carbon is heated, it is easy to form carbon chromium compounds to precipitate, causing the local Cr content to decrease and seriously affecting the corrosion resistance of stainless steel. Products that require welding are made of 316L material.
? - Normally, the strength of 316 is slightly higher than that of 316L material, so generally ferrule joints are made of 316 material.
8. Other materials commonly used in stainless steel products
-Polytetrafluoroethylene-PTFE (Teflon?, DuPont)
Working temperature -200~250℃, The best chemical stability, the material is soft, has cold flow properties, and the material has microchips falling off
-Polytrifluoroethylene—PCTFE (Kel-F?, 3M)
Work Temperature -200~120℃, chemical resistance second only to PTFE, high material strength, used in places with high pressure and high cleanliness requirements
-Fluorine rubber—Viton? (DuPont)
Working temperature -40~200℃, good chemical stability
9. Other materials commonly used in special gas products
-Monel?
Nickel-copper alloy , the percentage is about 63/28
-Hastelloy?
Nickel-chromium-molybdenum alloy, the percentage is about 56/22/13
-Alloy400?
Nickel-copper alloy, the percentage is about 66/32
-Vespel? Polyimide
High strength, high wear resistance, operating temperature up to 288°C.
-Kalrez? Perfluoroelastomer
Similar to PTFE in corrosion resistance, operating temperature up to 316°C
10. Basics of clean technology
< p> -Clean technology originated in the 1920s. The manufacturing of U.S. Air Force navigation gyroscopes required a clean production environment to improve yield and product life, resulting in the earliest concept of clean production;-In the early 1950s, With the advent of HEPA (high-efficiency particle air filter), the earliest clean room (clean room) appeared;
11. Cleanliness level
- The level of air cleanliness is based on units The volume is divided by the number of particles of a specified particle size.
- Generally, multiples of 10 are used for grading: such as level 10, level 100, level 1000, and level 10000.
Level -10 means that the number of dust particles larger than 0.5μm per square foot is less than 10pcs; converted to metric, it is 352pcs/m3.
12. Clean requirements for gas products
-The product material itself is required not to produce dust
-The gas flow channel has a high surface quality
- Requires almost absolute no leakage, safety and reliability
13. Electronic gases
- Commonly used gases in the semiconductor industry include silane (SiH4), phosphorane (PH3), germane (GeH4), boron trifluoride, phosphorus trifluoride, silicon tetrafluoride, etc.
- These gases are flammable, corrosive, and most of them are highly toxic. The product is required to be absolutely safe to use
- Rubber sealing cannot be used, and a metal-to-metal hard sealing structure must be used.
14. Introduction to stainless steel products
15. Pipe connection methods
-There are many ways to connect pipes
-Welding (butt welding) and socket welding)
-Direct pipe thread connection
-American standard NPT thread (profile angle 60°), national standard pipe thread G and R series (profile angle 55° )
-Single ferrule connection
-Double ferrule connection
-Expansion (expansion) joint connection
-Method Flange connection
16. Double ferrule joint
- Developed by SWAGELOK in the United States in 1947, it adopts a double ferrule structure.
-Tight connections with almost no leakage.
-It has good pressure resistance and is integrated with the pipeline.
- Very easy to install, no special tools required.
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19.STAINLESS? STEEL? FERRULE GRIP? AREA? HARDNESS
20.Double ferrule joint
-Assembly method
-Insert the pipe into the bottom of the joint and tighten the nut by hand
-Use a wrench to lock 1-1/4 turns, 3/16” (4mm)
- Lock 3/4 turns below to tighten
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22. Double ferrule performance
< p> - The strength of the ferrule joint is greater than that of the pipe. Even if the pipe breaks, the ferrule joint will not be detached or damaged.- It can be reused after disassembly and re-locked more than 25 times. Generally lock it to the original position and then lock it 1/12 turns
23. Double ferrule joint performance
- Fully replaceable, fully interchangeable with swagelok.
-He leakage detection, not greater than 1×10-8atm.cc/sec
-High and low temperature test (-40℃ to 150℃)
-Vibration test ( 1000,000 vibrations at 10-20Hz)
24. Pipeline requirements
- Relatively speaking, the requirements for pipes using ferrule joints are higher
-Generally, the tolerance of the outer diameter of the pipe is required to be less than ±0.1mm
-The cutout of the pipe is straight and there are no obvious scratches on the surface.
-The pipe mouth maintains a certain degree of roundness and cannot be irregular. Ellipse.
25. Working pressure of stainless steel pipes
26. System temperature influence coefficient
27. Pipes
-Tube & pipe< /p>
-Tube outer diameter is a nominal size, generally cold drawn or extruded
-Pipe inner diameter is a nominal size, cast, forged, welded
***Card Sleeve joints can only be used for tubes
28. Stainless steel valves
-The ferrule valves we currently produce include:
-Needle valves (NV series)< /p>
-Ball valve (BV series)
-One-way valve (CV series)
-Diaphragm valve (DV series)
29 .Stainless steel valve
-Needle valve----flow regulating valve
-Mainly adjusts the gas flow rate
-Simple structure, generally less used in semiconductors , making switch valves in the high-purity gas industry
-Serial numbers are classified according to diameter (or Cv value)
30. Stainless steel valves
-Ball valve- ---Switch valve
-The best switching ability
-According to the structure, it can be divided into three types: single-piece type, double-piece type and three-piece type
- Single-chip type: simple structure, high technical requirements, and high processing accuracy requirements. Used in instrumentation and high-purity gas industries.
31. Stainless steel valves
32. Stainless steel valves
-Diaphragm valve----switch valve
-Simple internal structure , generally used as switch valves in semiconductor and high-purity gas industries
33. Other stainless steel products
- Stainless steel filters
The filtration precision is 5, 10, 50μm three specifications