A butterfly valve is a regulating and shut-off device that can be an alternative, in some applications, with globe valve and ball valves.
This type of valve may be classified base on multiple parameters:
design: centric, double eccentric, triple eccentric
end connection type: wafer, lug (semi or full), flanged and double flanged
seat material: soft (example: Teflon, Buna, rubber, etc) or metal-to-metal (SS304, SS316)
body and disc materials (from cast iron to high nickel alloys)
actuation: manual (lever, gear, a worm gear) and actuated (electric, pneumatic, hydraulic and gas-over-oil types
A butterfly valve is used to shut off or modulate the flow of a fluid (isolation and regulation). API 609 Centric butterfly valves (soft seated) are preferred to gate and ball valves for low-pressure and non-critical applications as they are cheaper, lighter and easier to install. Eccentric butterfly valves (double offset and triple offset valves) with metal seats have surged in popularity and compete with globe and ball valves for some applications.
Duplex stainless steel (UNS S31803, S32205, S32750, S32900) combines the advantages of Ferrite and Austenite steel. Its duplex structure is conducive to obtaining high strength and stress resistance. In addition, higher content of chromium, nitrogen and molybdenum increases corrosion performance and duplex steel also has good welding performance. Due to its excellent properties, duplex stainless steel is widely used in chemical industry, paper manufacturing, desalination equipment, firewalls, Bridges, pressure vessels, heat exchangers, turbine blades and transmission shafts of offshore systems.
Sometimes, UNS S31803 and UNS S32205 are referred to as duplex 2205. Generally, UNS2205 contains ASTM S31803 and S32205 duplex stainless steels. In other words, S31803 and S32205 are both called 2205 stainless steel, and S32205 is the upgraded series of S31803 by the adding of the lower limit content of Cr, Mo and N elements, which makes the little difference in mechanical properties. Their tiny differences in chemical elements and physical properties are showed below:
UNS2205
C max
P
S
Si max
Mn max
N
Mo
Ni
Cr
S31803
0.03
0.03
0.02
1.00
2.00
0.08-0.2
2.5-3.5
4.5-6.5
21.0-23.0
S32205
0.03max
0.03
0.02
1.00max
2.00 max
0.14-0.2
3.0-3.5
4.5-6.5
22.0-23.0
UNS2205
Tensile strengthmin, Mpa
Yield strength0.2% offset, min, Mpa
Elongation, A5%
S31803
620
450
25
S32205
655
450
25
According to the ASTM A182 Standard, Specification for forged or stainless steel pipe Flanges, Forged Fittings, and Valves and Parts for High-Temperature Service, UNS S31803 and UNS S32205 cannot be confused and they specified in different number, S31803 is marked by F51 and S32205 is F60.
When speaking of 2205 steel, it generally refers to S31803 or F51, while UNS S32205 or F60 conforms to ASTM 2205 adopts its higher corrosion resistance range, that is, UNS S32205 requires higher Chromium and Nitrogen content, thus guaranteeing better corrosion resistance. Generally, S32205 steel plate and S31803 are also called double standard steel plate, or 2205 steel plate for short. Our factory produce 2205 tubing and 2205 plates to make its chemical composition conform to two specifications of UNS 31803 and S30025. Our steel plate in stock can meet two kinds of standards at the same time.
2205 (UNS S32305) is a nitrogen-alloyed duplex stainless steel, with a chemical composition containing 22-23% chromium, 3-3.5% molybdenum, and 4.5-6.5% nickel. The high chromium and molybdenum content provide good corrosion resistance, and the overall combination allows this alloy to be stronger and tougher than most standard austenitic steels. 2205 duplex stainless steels maintains good weldability in their thickest sections, and they are much more resistant to chloride stress corrosion cracking and pitting than standard austenitic steels like 316L or 317L.
With nearly twice the yield strength of other comparable austenitic grades, 2205 duplex steel products can withstand higher pressures and more corrosive environments with less material, saving on weight and fabrication costs. This makes them ideal for chemical processing and storage pressure vessels and tanks, or high chloride environments for marine applications.
United Performance Metals stocks 2205 duplex stainless steel plate in thicknesses from 0.125″ to 1.000″, with FirstCut+ Processing services available.
Heat Treatment and Heat Resistance
Similar to other duplex stainless steels, this grade of material can suffer from hydrogen embrittlement at temperatures over 300C. To solve this issue, 2205 duplex steel plate should be solution annealed at 1900°F (1038°C) minimum up to 2012°F (1100°C), followed by a water quenching for rapid cooling. While it can be work hardened, thermal treatments will not harden this grade of stainless steel.
Machining and Weldability
The high strength of duplex 2205 makes it difficult to machine. Strong, rigid machines with low vibration are recommended, and carbide tooling will require lower feed speeds. 2205 plate is easily welded, but care should be taken to use appropriate filler materials (such as 2209, which is over-alloyed with additional nickel) to prevent excess ferrite formation.
The purpose of a sight glass is to allow plant managers and engineers to look inside of their systems without disrupting the environment within. Often referred to as viewing glasses, they offer you a way to see the levels of liquids or gases that are traveling through a critical point of your design, monitor pressure changes, and virtually anything else that sight glass windows could allow you to do. With their widespread use, sight glasses have become critical to operations such as steam pipelines, chemical processing, pharmaceutical processing, and food processing.
The pipeline sight glass is one of the main accessories on the industrial pipeline device. It can observe the flow reaction of gas, liquid, steam and other media in the pipe at any time, monitor the production, and avoid accidents in the production process. Often used in chemical, chemical fiber, petroleum, pharmaceutical and other production pipelines
Repair and maintenance of pipe mirror
The Sight Glass is used to observe the flow of gas, liquid, steam and other media reaction equipment, its window glass should be kept clean without dust;
The Sight Glass of the mirror belongs to the appropriate damaged part, which should be handled with care when installing the mirror;
There are some limitations in the temperature and pressure resistance of Sight Glass
Function of check valve The fluid resistance of swing check valve is generally less than that of lift check valve, which can be divided into three types: single disc swing, double disc swing and multi disc swing. Swing check valve is suitable for large caliber occasions. For the swing check valve larger than 80mm installed at the pump outlet, the horizontal installation method shall be adopted to reduce the valve disc seating and impact. For the pipeline with the diameter of the check valve at the pump outlet greater than or equal to 150 mm, the bypass shall be set before and after the check valve to prevent the damage to the sealing surface of the check valve caused by the high pressure rise in front of the valve. The reason why the check valve does not work
The check valve is installed reversely. It shows that the pipeline medium flows, and the check valve blocks the flow.
Wrong selection or installation of check valve, such as vertical installation of check valve in vertical pipeline. For example, the flange connected lift check valve itself is installed vertically with the pipeline. The medium enters from the water inlet and pushes up the disc. The medium flows through the valve seat to another outlet of the check valve. The thrust to push the disc is less than the disc gravity, and the disc will fall naturally to the valve seat. If the valve is installed vertically, the gravity of the valve disc is all borne by the flange connected lift check valve, and the medium pushes the valve disc, only pushes the valve disc horizontally, and the valve disc cannot fall back to the valve seat naturally, causing the flange connected lift check valve to lose its function.
The internal parts of the check valve are rusted. It is shown as the connection parts inside the swing check valve.
The valve disc is not closed tightly due to the blockage of foreign matters
Valve disc is broken or has sand hole.
The check valves produced by Stv Valve Technology Group Co.,limited include swing check valve, lift check valve, ANSI check valve, DIN check valve, cast steel check valve, forged steel check valve and other materials.
Soft seal valve The sealing form is different, and the place of use is also different! In a nutshell Soft seal is generally used for normal temperature and pressure pipelines, while hard seal is widely used for high temperature and pressure! Hard seal valve
In the structural mechanism, the hard seal is the seal between metal and metal, and the sealing ball and valve seat are all metal. Machining accuracy and technology are relatively difficult, generally used in high pressure. Soft seal is the seal between metal and non-metal, such as nylon tetrafluoroethylene, the manufacturing standard is the same.
The soft and hard seal on the sealing material is for the sealing material of the valve seat. The hard seal is precisely processed with the valve seat material to ensure the matching accuracy with the valve core (ball), generally including stainless steel and copper. Soft seal means that the sealing material embedded in the valve seat is non-metallic material. Because the soft sealing material has certain elasticity, the requirements for machining accuracy are relatively low for hard seal.
In terms of manufacturing technology, due to the complex working environment of many chemical and mechanical industries, many of them are high temperature and high pressure, with high friction resistance and strong corrosiveness of the medium. Now the technology has improved, the application of various materials is better, and the processing and other aspects can keep up with it, so that the hard sealed ball valve can be widely promoted. In fact, the principle of hard seal ball valve is the same as that of soft seal ball valve, only because of the sealing between metals, the hardness relationship between metals, working condition and medium should be considered. Generally, it is required to do hardening treatment, and the ball and valve seat should be continuously ground to achieve sealing. The production cycle of hard seal ball valve is long and the processing is complex. It is not easy to make hard seal ball valve.
Generally, the soft seal can reach a high level, while the hard seal can reach a high level according to the requirements; the soft seal needs fire protection, because under high temperature, the material of the soft seal will leak, while the hard seal does not; the hard seal can generally do a high pressure, but the soft seal cannot; the soft seal cannot be used in some occasions due to the problems of the flowing medium Finally, hard sealed ball valves are generally more expensive than soft sealed ones. As for manufacturing, there is little difference between the two, mainly the difference between the valve seat. The soft seal is non-metal, and the hard seal is metal.
The selection of soft and hard sealing ball valves is mainly based on the process medium, temperature and pressure. Generally, the medium containing solid particles or with wear or temperature higher than 200 degrees is the best choice for hard sealing. When the diameter is greater than 50, the valve pressure difference is large, and the valve opening torque is also considered. When the torque is large, the fixed hard sealing ball valve should be selected. The sealing grade of soft and hard sealing can reach 6 Class.
We finished and delivered Ansi 150, Carbon Steel Y Strainer Purchase Order Number: STV20191005 Requested the valve inside & outside to be done painting
Product description: Available in PN16/40 or ANSI 150lb flanged,JIS Flange sizes: 1/2″ to 24″ Temperature range: -29 to 560°C . Pressure rating: DIN PN16-PN40 or ANSI 150LB-1500LB,JIS10K-30K Body Material,WCB,CF8,CF8M,WC6 AND WC9 Etc.
We delivered a Big Size Swing Check valves to one of European customers.
ASTM A351 CF8 304 Stainless Steel Body, Cover and Disc. 304 Stainless Steel Trim. PTFE Cover Seal. Bolted Cover Design. Face to Face dimensions in accordance with ANSI B16.10 Class 300 pressure rated. -20 / +200 deg C Temp rated. Flanged ANSI 300 end connections. Size:3″Painting: Inside and outside not painted. Bolts and nuts between the body and bonnet and also the gland nuts and gland eye bolts made of steel A193-B8/A194-8 Material: Body/bonnet CF8 Pressure:300LB Stem packing graphite. Size:32 Inch
