valve manufacturer Archives

How to choose a valve in the chemical industry

August 5, 2021

The media transported in various pipelines in the chemical industry are usually corrosive, such as sulfuric acid, hydrochloric acid, nitric acid and other corrosive media. All corrosion protection is the most basic requirement of chemical equipment. Chemical valves are of course no exception, and the selection of valve materials must be corrosion-resistant. If the chemical valve is wrongly selected, it will damage the equipment at the slightest level, or cause serious accidents, causing injury to machinery, equipment and even people. However, for different corrosive media, the selection of valves is also different. This article will talk about the key points of valve material selection for some common chemical media:

lug type butterfly valve, ductile iron, center lined,

Hydrochloric acid: Most metal materials, including various stainless steel materials, are not resistant to hydrochloric acid corrosion, and high-silicon ferro-molybdenum can only be used in hydrochloric acid below 50°C and 30%. Contrary to metal materials, most non-metal materials have good corrosion resistance to hydrochloric acid, so rubber-lined valves (such as fluoroplastics, etc.) are the best choice for transporting hydrochloric acid. But if the temperature of the medium exceeds 150°C, or the pressure is greater than 16 kg, any plastics (including fluoroplastics and even polytetrafluoroethylene) will be difficult to handle. For hydrochloric acid exceeding this condition, there is no ideal valve currently on the market.

Sulfuric acid: As one of the strong corrosive media, sulfuric acid is an important industrial raw material with a wide range of uses. Different concentrations and temperatures of sulfuric acid have great differences in the corrosion of materials. For concentrated sulfuric acid with a concentration of more than 80% and a temperature of less than 80°C, carbon steel and cast iron have good corrosion resistance, but it is not suitable for high-speed flowing sulfuric acid. Not suitable for use as a valve material; ordinary stainless steels such as 304 and 316 have limited use for sulfuric acid media. Therefore, pump valves for transporting sulfuric acid are usually made of high-silicon cast iron (difficult to cast and process) and high-alloy stainless steel (20 alloy valve). Fluoroplastics have better resistance to sulfuric acid, and fluorine-lined valves (recommended by Tanghai Valves) are a more economical choice. If the pressure is too high and the temperature rises, the point of use of the plastic valve will be impacted, and you can only choose the more expensive ceramic ball valve.

Nitric acid: Most metals are rapidly corroded and destroyed in nitric acid. Stainless steel is the most widely used nitric acid resistant material. It has good corrosion resistance to all concentrations of nitric acid at room temperature. Note that stainless steel containing molybdenum (such as 316, The corrosion resistance of 316L) to nitric acid is not better than that of ordinary stainless steel (such as 304, 321), and sometimes even worse.

Acetic acid: Acetic acid is one of the most corrosive substances in organic acids. Ordinary steel will be severely corroded in acetic acid at all concentrations and temperatures. Stainless steel is an excellent acetic acid resistant material. 316 stainless steel containing molybdenum is also suitable for high temperature and rarefied materials. Acetic acid vapor. For demanding requirements such as high temperature and high concentration of acetic acid or other corrosive media, high alloy stainless steel or fluoroplastic pumps can be used.

Salt water/sea water: The corrosion rate of ordinary steel in sodium chloride solution, sea water and salt water is not very high, and generally must be protected by paint; all kinds of stainless steel also have a very low uniform corrosion rate, but may cause local corrosion due to chloride ions. It is usually better to use 316 stainless steel.

TH Valve is a professional manufacturer of butterfly valve, gate valve, check valve, globe valve, knife gate valve, ball valve with API, JIS, DIN standard, used in Oil, Gas, Marine industry, Water supply and drainage, fire fighting, shipbuilding, water treatment and other systems, with Nominal Diameter of DN50 to DN1200, NBR/EPDM/VITON, Certificates & Approvals: DNV-GL, Lloyds, DNV, BV, API, ABS, CCS. Standards: EN 593, API609, API6D

electric butterfly valve code naming method

August 3, 2021

Electric butterfly valve model preparation method, electric butterfly valve code naming method, only suitable in China.
With the increase in demand for valves in my country’s industrial manufacturing industry, electric butterfly valves have become a more prominent one among many valves. However, due to the wide variety of electric butterfly valves, and the difference in control modes and medium pressure and temperature, users often choose electric Uncertainty about butterfly valve models! In order to avoid such a situation, our company specially provides the electric butterfly valve model preparation instructions for your reference and understanding!

lug type butterfly valve, ductile iron, center lined,

The electric butterfly valve model preparation instructions include the addition of additional conditions for the butterfly valve, the difference in connection methods, the upgrade of the transmission mode, the change of the structure, the level of valve pressure, and the requirements for temperature, pressure, corrosion and material. Hope It is helpful to everyone in the selection!
Model representation method of electric butterfly valve:
Additional codes for electric butterfly valves: BD thermal insulation butterfly valve, SD telescopic butterfly valve, TLD desulfurization butterfly valve, DH check butterfly valve, DKS fast butterfly valve, FDBD square louver butterfly valve;
The code of the butterfly valve: D represents the butterfly valve;
Transmission form code: manual (omitted), 3 means turbine drive, 6 means pneumatic drive, 7 means hydraulic, 9 means electric;
Connection code: 4 flange type, 6 welding, 7 pair clip type;
Code of structural form: 1 means centerline type, 2 means double eccentricity, 3 means triple eccentricity, 4 means variable eccentricity, 5 means single eccentricity;
Sealing material code: H stainless steel, X rubber, F polytetrafluoroethylene, FX composite rubber, M Monel alloy, Y cemented carbide, W valve body directly processed;
Pressure grade code: 10=PN1.0Mpa, 16=PN1.6, 25=PN2.5, 40=PN4.0, PN is the code of domestic pressure, MPA is the unit of pressure, one kilogram is equal to 0.1Mpa; Class150LB=1.6 mpa, 300LB=2.5-4.0mpa, Class is the American standard code, LB is the American standard pound unit.
Shell material code: C cast steel, P stainless steel 304, R stainless steel 316, AL special alloy steel, Z cast iron, Q ductile iron, N nylon. To
The above are common codes related to butterfly valves. For products that need to be customized due to special working conditions, they can be selected according to the design plan.
Electric butterfly valve model preparation instructions: D943H-16C Stainless steel electric flange hard-sealed butterfly valve

D943H-16C-metal seated stainless steel electric triple offset butterfly valve

D: Represents butterfly valve;
9: Indicates that the transmission mode is electric;
4: The connection method is flange connection;
3: The structure is triple eccentric;
H: The sealing material is stainless steel;
16: Indicates that the nominal pressure is 1.6MPa;
P: Indicates that the valve body is made of stainless steel.
Related valve model: Pneumatic butterfly valve model Electric ball valve model Pneumatic ball valve model

TH Valve is a professional manufacturer of butterfly valve, gate valve, check valve, globe valve, knife gate valve, ball valve with API, JIS, DIN standard, used in Oil, Gas, Marine industry, Water supply and drainage, fire fighting, shipbuilding, water treatment and other systems, with Nominal Diameter of DN50 to DN1200, NBR/EPDM/VITON, Certificates & Approvals: DNV-GL, Lloyds, DNV, BV, API, ABS, CCS. Standards: EN 593, API609, API6D

Pneumatic butterfly valve installation instructions

July 29, 2021

Pneumatic butterfly valve installation instructions and steps
Whether the pneumatic butterfly valve is installed well will affect the efficiency of the equipment. And the maintenance of the pneumatic butterfly valve is also related to the performance of the equipment. Improper installation or lack of maintenance will cause the performance of the butterfly valve to decline, and even unnecessary dangers. The user should check and maintain the pneumatic butterfly valve as scheduled.

D673H-16C-stainless steel pneumatic triple eccentric butterfly valve

1. Before installation, check that all parts of the pneumatic butterfly valve are not missing, the model is correct, there is no debris in the valve body, and there is no blockage in the solenoid valve and muffler;
2. Put the valve and cylinder in the closed state.
3. Hit the cylinder against the valve (the installation direction is either parallel or perpendicular to the valve body), and then check whether the screw holes are aligned, there will be no too much deviation, if there is a little deviation, just rotate the cylinder body a little. , And then tighten the screws.
4. After installation, debug the pneumatic butterfly valve (the air supply pressure is 0.4~0.6MPa under normal circumstances), and the solenoid valve must be opened and closed manually during the debugging operation (the solenoid valve coil can only be operated manually after the solenoid valve coil is de-energized). Observe the opening and closing of the pneumatic butterfly valve. If the valve is found to be a bit difficult at the beginning of the opening and closing process during the debugging operation, and then it is normal, you need to reduce the stroke of the cylinder (the stroke adjustment screws at both ends of the cylinder should be adjusted inward at the same time, and the valve should be moved to the open position during adjustment. , Then turn off the air source and adjust again) until the valve opens and closes smoothly and closes without leakage. It should also be noted that the adjustable silencer can adjust the opening and closing speed of the valve, but it should not be adjusted too small, otherwise the valve may not operate.
5. Defa should be kept dry before installation, and should not be stored in the open air;
6. Check the pipeline before installing the butterfly valve to ensure that there is no foreign matter such as welding slag in the pipeline;
7. The manual opening and closing resistance of the butterfly valve body is moderate, and the torque of the butterfly valve matches the torque of the selected actuator.
8. The flange specification for butterfly valve connection is correct, and the pipe clamp flange conforms to the

ductile iron, DI, butterfly valve, manufacturer, center line, TH valve

butterfly valve flange standard. It is recommended to use special flanges for butterfly valves instead of flat welding flanges.
9. Confirm that the flange welding is correct. After the butterfly valve is installed, the flange must not be welded to avoid scalding the rubber parts.
10. The installed pipe flange should be centered and centered with the inserted butterfly valve.
11. Install all the flange bolts and tighten them by hand. It will be confirmed that the butterfly valve and the flange have been aligned, and then the butterfly valve will be opened and closed carefully to ensure flexible opening and closing.
12. Fully open the valve. Use a wrench to tighten the bolts in diagonal order. No washers are needed. Do not overtighten the bolts to prevent serious deformation of the valve ring and excessive opening and closing torque.
Related knowledge: Installation instructions for ventilation butterfly valves; Installation instructions for telescopic butterfly valves

TH Valve is a professional manufacturer of butterfly valve, gate valve, check valve, globe valve, knife gate valve, ball valve with API, JIS, DIN standard, used in Oil, Gas, Marine industry, Water supply and drainage, fire fighting, shipbuilding, water treatment and other systems, with Nominal Diameter of DN50 to DN1200, NBR/EPDM/VITON, Certificates & Approvals: DNV-GL, Lloyds, DNV, BV, API, ABS, CCS. Standards: EN 593, API609, API6D

Structural characteristics of metal hard seal butterfly valve

July 29, 2021

Structural characteristics of metal hard seal butterfly valve
The metal hard seal butterfly valve is mainly composed of valve body, butterfly plate, valve shaft, valve body sealing ring, butterfly plate sealing ring, shaft sleeve, self-lubricating bearing, driving device and so on. The high-performance metal hard seal butterfly valve drives the valve shaft to rotate through various driving devices, and the pin shaft drives the butterfly plate to rotate within 90°, so that the butterfly plate is in the open or closed state, so as to achieve the purpose of connecting or cutting off. It is widely used in metallurgy, hydropower, thermal power, thermal power, urban water supply and drainage, farmland irrigation and drainage and other industries. The applicable medium is gas, steam, air, water, etc., in the pipeline system.

triple eccentric butterfly valve-lug

Structural features of metal sealing butterfly valve:
①The unique design of three-way eccentricity enables frictionless transmission between the sealing surfaces and prolongs the service life of the valve.
②The elastic seal is produced by the torque.
③The ingenious wedge-shaped design makes the valve have the function of automatic sealing as the valve closes tighter and tighter, and the sealing surface has compensation and zero leakage.
④Small size, light weight, light operation, easy to install.
⑤Pneumatic and electric devices can be configured according to user requirements to meet the needs of remote control and program control.
⑥The material of replacement parts can be applied to various media, and can be lining anti-corrosion (lining F46, GXPP, PO, etc.).
⑦The sealing ring is made of stainless steel, which has the dual advantages of metal hard seal and elastic seal. It has excellent sealing performance regardless of low temperature and high temperature.
The difference between metal hard seal butterfly valve and rubber seal butterfly valve:
The disadvantage of the rubber seal butterfly valve is that when it is used for throttling, cavitation will occur due to improper use, causing the rubber seat to peel off and damage. For this reason, the metal sealing butterfly valve has been developed internationally. The metal hard sealing butterfly valve is an eccentric metal sealing structure, and the sealing form is metal to metal sealing. The metal sealing ring can be exchanged for metal sealing, and the stainless steel plate and graphite composite plate sealing ring is sealing to metal. .

The high-performance elastic metal sealing butterfly valve adopts a double eccentric and a special oblique cone oval sealing structure. It solves the shortcoming of the traditional eccentric butterfly valve that the sealing surface is still in sliding contact friction at the moment of opening and closing 0°～10°, and the sealing surface of the butterfly plate is separated at the moment of opening, and the effect of closing the contact is sealing, so as to extend the service life and maximize the sealing performance.
Related knowledge: the principle of butterfly valve structure
Related products: Electric hard-sealed butterfly valve Pneumatic hard-sealed butterfly valve

TH Valve is a professional manufacturer of butterfly valve, gate valve, check valve, globe valve, knife gate valve, ball valve with API, JIS, DIN standard, used in Oil, Gas, Marine industry, Water supply and drainage, fire fighting, shipbuilding, water treatment and other systems, with Nominal Diameter of DN50 to DN1200, NBR/EPDM/VITON, Certificates & Approvals: DNV-GL, Lloyds, DNV, BV, API, ABS, CCS. Standards: EN 593, API609, API6D

Fluorine-lined butterfly valve vs metal seated butterfly valve

July 23, 2021

The difference and selection of fluorine-lined butterfly valve and metal seated butterfly valve
As one of the most commonly used valves in process pipelines, butterfly valves are not only simple in structure, easy to operate, and equipped with different driving devices, but also can form a variety of control methods, such as electric butterfly valves, hydraulic butterfly valves, pneumatic butterfly valves, etc.! Moreover, butterfly valves are often used in occasions with large caliber and flow. Compared with other valves of the same caliber, the cost can be reduced by 1.5 to 2 times, which is economical and practical!

Fluorine lined butterfly valve-PTFE-DOUBLE FLANGE (2)

According to the different sealing forms of butterfly valves, they can be divided into two categories, one is soft seal and the other is metal seated! The two butterfly valves with different sealing forms play different roles in the relatively used pipelines. In a sense, there are still big differences! When choosing, users should have a detailed understanding and awareness of the difference between the two!

Take the most common soft-sealed fluorine-lined butterfly valves and metal hard-sealed butterfly valves, fluorine-lined butterfly valves are generally used for pipelines containing corrosive media, and the sealing effect can reach zero leakage, but it is only suitable for normal temperature and pressure! The hard-sealed butterfly valve is relatively high in temperature and pressure, but the sealing and corrosion resistance are not as good as the soft-sealed butterfly valve!
1. From the structure: The metal seated butterfly valve refers to the metal material or other harder materials on both sides of the sealing pair. For soft sealing butterfly valves, the two contacting sealing surfaces can be separate or all of soft materials. For example, fluorine-lined butterfly valve means that the butterfly plate and valve seat are both wrapped in PTFE;

triple offset butterfly valve-double flange- (5)

2. In terms of sealing performance: The advantage of the soft-sealed fluorine-lined butterfly valve is that it has good sealing performance, but the disadvantage is that it is easy to age, wear, and has a short service life. The metal seated butterfly valve has a long service life, but the sealing performance is relatively worse than that of the soft seal.
3. From the conditions of use: The soft-sealed fluorine-lined butterfly valve is used in normal temperature and pressure environments, while the hard-sealed butterfly valve can be used in low temperature, normal temperature, high temperature and other environments. Generally, it can be used for higher pressure, but the soft seal is not. However, the fluorine-lined butterfly valve has Super corrosion resistance!
4. From the manufacturing aspect: As for the manufacturing, from the principle point of view, the difference between the two is not big, mainly the difference in the valve seat. The soft-sealed fluorine-lined butterfly valve is a non-metallic structure, and the hard-sealed butterfly valve is a metal structure. It is necessary to consider the metal structure. The relationship between the hardness, the working conditions, what medium is used, and so on.

TH Valve is a professional manufacturer of butterfly valve, gate valve, check valve, globe valve, knife gate valve, ball valve with API, JIS, DIN standard, used in Oil, Gas, Marine industry, Water supply and drainage, fire fighting, shipbuilding, water treatment and other systems, with Nominal Diameter of DN50 to DN1200, NBR/EPDM/VITON, Certificates & Approvals: DNV-GL, Lloyds, DNV, BV, API, ABS, CCS. Standards: EN 593, API609, API6D

The role and use of the ball valve

July 16, 2021

The function of the ball valve:
The opening and closing part of the ball valve is a round sphere with a hole. The ball core rotates around the axis of the valve stem by 0-90° back and forth to achieve the purpose of opening or closing the valve. Ball valves have many functions. They are generally used to switch off or adjust the medium in the pipeline. Among them, the three-way ball valve can flexibly cut off, distribute and change the flow direction of the medium. The sealing surface of the ball valve is usually closed with the spherical surface, so it is not easy to be eroded by the medium. It is easy to operate and has a simple and compact structure. It can be used in working conditions such as water, natural gas, acid, and solvent.

fixed ball valve

The application of the ball valve:
Ball valves can generally be divided into three categories: floating ball valves, fixed ball valves, and elastic ball valves according to their structure. According to the different sealing performance, it is divided into hard-sealed ball valves and soft-sealed ball valves. The soft-sealed ball valves have better sealing performance and can achieve zero leakage. They are generally used in normal temperature and pressure pipelines with corrosive media, while hard-sealed ball valves are not only It can be used in normal temperature and pressure, as well as pipelines with low temperature and low pressure and high temperature and high pressure.
(1) Floating ball valve
The ball of the floating ball valve is floating and is supported by two valve seats. Under the action of the medium pressure, the ball can produce a certain displacement and tightly adhere to the sealing surface of the valve seat at the outlet end to ensure that the outlet end is sealed. However, if the sphere bears the load of the working medium and is all transmitted to the outlet sealing ring, the sphere may deviate when it is impacted by a higher pressure. Therefore, the ball valve of this structure is generally suitable for normal pressure or low pressure working conditions.
(2) Fixed ball valve

Pneumatic electric high platform ball valve

The name of the fixed ball valve is that the ball is fixed, and when the valve is closed, the ball valve will not move even if it is pressurized. Fixed ball valves are equipped with a floating seat. After being pressured by the medium, the seat will move so that the sealing ring is pressed tightly on the sphere to ensure sealing. Generally, sliding bearings or rolling bearings are installed on the upper and lower shafts of the ball, which can be operated with a small torque and a small torque, and is generally suitable for high-pressure and large-diameter pipelines.
Other common classifications of ball valves, chip ball valves, orbital ball valves, V-shaped ball valves, O-shaped ball valves, cut-off ball valves, three-way ball valves, four-way ball valves, forged steel ball valves, ash unloading ball valves, anti-sulfur ball valves, eccentric ball valves, thermal insulation ball valves, pneumatic Ball valves, electric ball valves, ferrule ball valves, welded ball valves. Among them, the V-shaped ball valve has a shearing effect, which is especially suitable for media containing fibers, small solid particles, slurry and other media. The three-way ball valve can also be divided into T-type and L-type. The T-shape can make the three intersecting pipelines connect to each other or cut off any one of the channels, playing the role of splitting and merging. The L-shape only connects two perpendicular pipes, and cannot connect to the third pipe at the same time, and it mainly plays a role of distribution.
Related knowledge: working principle of ball valve structure diagram of ball valve.

TH Valve is a professional manufacturer of butterfly valve, gate valve, check valve, globe valve, knife gate valve, ball valve with API, JIS, DIN standard, used in Oil, Gas, Marine industry, Water supply and drainage, fire fighting, shipbuilding, water treatment and other systems, with Nominal Diameter of DN50 to DN1200, NBR/EPDM/VITON, Certificates & Approvals: DNV-GL, Lloyds, DNV, BV, API, ABS, CCS. Standards: EN 593, API609, API6D

V-type regulating ball valve

July 1, 2021

Working principle of pneumatic V-type regulating ball valve
The ball core of the pneumatic V-shaped regulating ball valve is designed with a special V-shaped notch, which has a shearing effect on the valve seat. It is especially suitable for media containing fibers, small solid particles, slurry and other media. According to different structural methods, it can generally be divided into flange and Wafer type; Pneumatic V-type ball valve is a fixed ball valve and also a single-seat sealed ball valve. It has the best adjustment performance among ball valves and can achieve flow adjustment. At the same time, since the valve core and seat are rotated without gaps, they can be wiped by themselves. The fouling on the ball and valve seat keeps a good seal between the ball and the valve seat.

electric V type ball valve

Working principle of pneumatic V-shaped regulating ball valve:
Pneumatic V-shaped regulating ball valve realizes different degrees of proportionality according to the V-shaped angle of the V-shaped sphere. It is generally used in conjunction with a valve positioner to achieve proportional adjustment. The V-shaped spool is most suitable for various adjustment occasions and has a large rated flow coefficient. ,, The pressure loss is small, the use flow capacity is large, and it has accurate shut-off characteristics and control functions. The flow characteristics are approximately equal percentages. The opening and closing parts adopt the V-shaped ball structure, which completely solves the problem of easy deposition of medium in the valve cavity.
Features of pneumatic V-shaped regulating ball valve:
1. Pneumatic V-shaped ball valve V-shaped gap and valve seat produce a strong shear force to cut off impurities such as fibers, and has a self-cleaning function to avoid valve jamming.
2. The pneumatic V-type regulating ball valve has an inherent flow characteristic of approximately equal percentage and an adjustable ratio of up to 300:1, so it can provide precise control in a wide range of changes.

Note: Because the pneumatic V-type regulating ball valve is generally a single-seat sealed ball valve, it is not suitable for two-way use. Due to its streamlined shape and full right-angle rotation control, the maximum volume is extremely high, the flow capacity is particularly large, and the flow resistance is small.

pneumatic V type ball valve

Pneumatic V-type regulating ball valve principle dynamic diagram
The valve core of the pneumatic V-shaped regulating ball valve is designed as a V-shaped gap with a special switch. The V-shaped gap and the valve seat generate a strong shear force, which can cut off high-viscosity media containing fibers or small solid particles, and has a self-cleaning function , To avoid the phenomenon of valve jamming. Pneumatic V-shaped ball valve is suitable for regulation and control, with high stability. Even in the case of small flow or high-viscosity medium, it can also ensure the accuracy of control within the entire range; while O-shaped ball valve is suitable for cutting off, relatively It is economical.
There is a V-shaped opening on the sphere of the pneumatic V-shaped regulating ball valve. As the ball rotates, the opening area changes, but the shape of the opening surface is always triangular. The flow characteristics are approximately equal percentages, the adjustable ratio is large, and the pressure loss is small. The flow capacity is large, and it has accurate interception characteristics and control functions. The opening and closing parts adopt a V-shaped spherical structure, which completely solves the problem of easy deposition of medium in the valve cavity. It is suitable for fibrous and slurry fluids!
The angle of the V-shaped port of the pneumatic V-shaped ball valve can be customized to meet more precise shut-off characteristics and control functions. Generally, more V-shaped valves are used in slurry media. They are similar to cam flex valves and are much better than O-shaped valves. V-shaped ball valves are used as regulating valves. For example, if the medium is not clean, the flow coefficient is low, and the leakage level is high, etc. occasion.

Working principle of electric V-type regulating ball valve

V type ball valve drawing

The electric V-shaped regulating ball valve has a special-shaped V-shaped incision. When the valve is closed, the V-shaped incision and the valve seat form a wedge shape, which has a shearing effect. The electric V-shaped ball valve is suitable for the control of fibrous slurry, sewage and viscous particle media. It can prevent the seizure of dirt between the ball and the valve seat. It has a self-cleaning function and is a wide-ranging regulating valve.
When the electric V-shaped ball valve rotates, the V-shaped blade of the ball is tangent to the valve seat, thereby cutting off the fiber and solid matter in the fluid. However, the general ball valve does not have this function, so it is easy to cause the fiber impurities to get stuck when closed. , Bring great inconvenience to repair and maintenance. The valve core of the electric V-shaped ball valve will not be jammed by the fiber, and the flow rate of the pipeline medium is adjusted and controlled according to the change of the opening area of the V-shaped gap.
Note: Since the electric V-type regulating ball valve is generally a single-seat sealing ball valve, it is not suitable for two-way use. The integral valve body structure is adopted, and there is no potential for leakage.
Features of electric V-shaped ball valve:
1. It has the advantages of compact structure, small volume, vertical and horizontal installation, etc., adopts movable metal valve seat, self-compensation function, and has superior sealing performance and long service life.
2. The electric V-shaped ball valve adopts a double-bearing structure, which has high mechanical stability and low starting torque, which ensures that the valve has excellent sensitivity and induction speed.
3. Maximum reliability (safety): The valve body is a whole, sturdy and durable, operation is not affected by pipeline pressure, and leakage of the valve body can be avoided.
4. The V-shaped gap and valve seat of the electric V-shaped regulating ball valve produce a strong shearing force to cut off impurities such as fibers, and has a self-cleaning function to avoid valve jamming.
5. Maximum flow volume: Due to the streamlined shape of the electric V-shaped ball valve and the full right-angle rotation control, the maximum volume is particularly high, the flow capacity is particularly large, and the flow resistance is small.

TH Valve is a professional manufacturer of butterfly valve, gate valve, check valve, globe valve, knife gate valve, ball valve with API, JIS, DIN standard, used in Oil, Gas, Marine industry, Water supply and drainage, fire fighting, shipbuilding, water treatment and other systems, with Nominal Diameter of DN50 to DN1200, NBR/EPDM/VITON, Certificates & Approvals: DNV-GL, Lloyds, DNV, BV, API, ABS, CCS. Standards: EN 593, API609, API6D

Butterfly valve flange types and introduction

June 28, 2021

Butterfly valve flange introduction, butterfly valve flange types
Butterfly valve flanges are called flanges and flanged parts. It is a product that connects valves and pipes in pipelines. The special flanges for butterfly valves are the same as ordinary flanges, that is, the inner hole is different. The special flange of the butterfly valve has a small inner hole and an extra slot for intubation.

flange TG-

The butterfly valve flange can be a single type or a combined type, such as the flanges at both ends of the valve, which is convenient for installing bolts. One end of the pipe and the other end are flange-to-flange connection, or a connection joint, which refers to a foldable connection that is connected to each other by flanges, gaskets and bolts as a set of combined sealing structures. Pipe flanges refer to pipe installations. The flange used in the middle piping, the valve refers to the flange of the valve, the flange has holes, bolts make the two flanges tightly connected, and the flange is sealed with gaskets.
[Butterfly valve flange material] No. 20, A105, Q235A, 12Cr1MoV, 16MnR, 15CrMo, 18-8, 321, 304, 304L, 316, 316L.
[Sealing surface form] Flat surface (FF), raised surface (RF), convex surface (M), concave surface (F), concave and convex surface (MF), tenon surface (T), groove surface (G), tongue and groove surface (TG) , Ring connection surface (RJ).
[According to petrochemical industry standards] Threaded flange (PT), butt welding flange (WN), flat welding flange (SO), socket welding flange (SW), loose flange (LJ), flange cover ( No note).
[According to mechanical industry standards] Butterfly valve flange pictures: Integral flange, butt welding flange, plate flat welding flange, butt welding ring plate loose flange, flat welding ring plate loose flange, flange ring plate loose flange method Lan, flange cover.
[According to national standards] Integral flanges, threaded flanges, butt welding flanges, flat welding flanges with necks, socket welding flanges with necks, butt welding ring loose flanges with necks, plate flat welding flanges, Welded ring plate loose flange, flat welded ring plate loose flange, flanged ring plate loose flange, flange cover.
[According to chemical industry standards] Integral flange (IF), threaded flange (Th), plate flat welding flange (PL), diameter butt welding flange (WN), neck flat welding flange (SO), bearing Insert welding flange (SW), butt welding ring loose flange (PJ/SE), flat welding ring loose flange (PJ/RJ), lining flange cover (BL (S)), flange cover (BL ).
Related products: 7types of flange sealing surface; Pneumatic flanged butterfly valve

TH Valve is a professional manufacturer of butterfly valve, gate valve, check valve, globe valve, knife gate valve, ball valve with API, JIS, DIN standard, used in Oil, Gas, Marine industry, Water supply and drainage, fire fighting, shipbuilding, water treatment and other systems, with Nominal Diameter of DN50 to DN1200, NBR/EPDM/VITON, Certificates & Approvals: DNV-GL, Lloyds, DNV, BV, API, ABS, CCS. Standards: EN 593, API609, API6D

Prevention and treatment of valve corrosion

June 16, 2021

What is valve corrosion?
Corrosion of the valve is usually understood as the damage to the metal material of the valve under the action of a chemical or electrochemical environment. Since the “corrosion” phenomenon occurs in the spontaneous interaction between the metal and the surrounding environment, how to isolate the metal from the surrounding environment or use more non-metallic synthetic materials is the focus of corrosion prevention. The valve body (including the bonnet) of the valve occupies most of the weight of the valve and is in constant contact with the medium. Therefore, the selection of the valve is often based on the material of the valve body.

Fluorine lined butterfly valve-PTFE-WAFER (8)

The corrosion of the valve body is nothing more than two forms, namely chemical corrosion and electrochemical corrosion. Its corrosion rate depends on the temperature, pressure, chemical properties of the medium and the corrosion resistance of the valve body material. The corrosion rate can be divided into six levels:
1. Complete corrosion resistance: the corrosion rate is less than 0.001 mm/year;
2. Extremely resistant to corrosion: the corrosion rate is 0.001 to 0.01 mm/year;
3. Corrosion resistance: the corrosion rate is 0.01 to 0.1 mm/year;
4. Still corrosion resistant: the corrosion rate is 0.1 to 1.0 mm/year;
5. Poor corrosion resistance: the corrosion rate is 1.0 to 10 mm/year;
6. Not resistant to corrosion: the corrosion rate is greater than 10 mm/year.

How to prevent valve corrosion?
The anti-corrosion of the valve body is mainly based on the correct selection of materials. Although there are abundant anti-corrosion materials, it is not easy to choose the right one, because the problem of corrosion is very complicated. For example, sulfuric acid is very corrosive to steel when the concentration is low, and when the concentration is high, the steel is produced. Passivation film can prevent corrosion; hydrogen only shows strong corrosiveness to steel under high temperature and high pressure. The corrosion performance of chlorine is not great when it is in a dry state, but it is very corrosive when there is a certain humidity, and many materials cannot be used. . The difficulty in selecting valve body materials lies in not only considering corrosion issues, but also factors such as pressure resistance and temperature resistance, whether it is economically reasonable, and whether it is easy to purchase. So it must be attentive.
1. The second is to take lining measures, such as lining lead, lining aluminum, lining engineering plastics, lining natural rubber and various synthetic rubbers. If the media conditions permit, this is an economical method.
Second, again, when the pressure and temperature are not high, the main material of the fluorine-lined valve can often be very effective in preventing corrosion.
3. In addition, the outer surface of the valve body is also corroded by the atmosphere, and generally steel materials are protected by painting.

TH Valve is a professional manufacturer of butterfly valve, gate valve, check valve, globe valve, knife gate valve, ball valve with API, JIS, DIN standard, used in Oil, Gas, Marine industry, Water supply and drainage, fire fighting, shipbuilding, water treatment and other systems, with Nominal Diameter of DN50 to DN1200, NBR/EPDM/VITON, Certificates & Approvals: DNV-GL, Lloyds, DNV, BV, API, ABS, CCS. Standards: EN 593, API609, API6D

Flange telescopic butterfly valve application | advantages and disadvantages | installation instructions

June 10, 2021

Flange telescopic butterfly valve application|advantages and disadvantages|installation instructions
Flange telescopic butterfly valve application:
The butterfly plate of the flange telescopic butterfly valve is installed in the diameter direction of the pipeline. In the cylindrical passage of the telescopic butterfly valve body, the disc-shaped butterfly plate rotates around the axis, and the rotation angle is between 0° and 90°. When the rotation reaches 90°, the valve is fully opened. Applicable temperature≤80℃, used in petroleum, chemical, food, medicine, textile, papermaking, electric power, water supply and drainage, gas pipelines, as the function of regulating flow and intercepting medium, and has the function of compensating for thermal expansion and contraction of pipelines.

Double flange butterfly valve (16)

Advantages and disadvantages of flange telescopic butterfly valve:
Flange retractable butterfly valve (the structural length can be extended within a certain range), which not only brings convenience for valve disassembly, but also relieves pipeline stress and protects the valve. At the same time, it also condenses the installation method of butterfly valve plus retractor, and space More compact. Normally, this type of valve does not require special maintenance, and only needs to be regularly observed for leakage and pull-off in the telescopic part. The initial cost of flange expansion butterfly valve is lower than the installation method of flange butterfly valve plus expansion, but considering the maintenance cost in the future, the gain is not worth the loss.
If the sealing part of the butterfly valve is damaged and the sealing ring cannot be replaced and the butterfly valve needs to be scrapped, then the telescopic part will be scrapped together, resulting in greater loss. For example, when the sealing part of the butterfly valve needs maintenance, only the compression and expansion part cannot realize the valve-free online maintenance. However, the installation method of the butterfly valve and the expansion device has a great advantage. Only the expansion device needs to be removed, that is, manual Large maintenance space to realize valve free maintenance (butterfly valve is heavy, retractor is light, and labor intensity is low).
Precautions for installation of flange telescopic butterfly valve:
1. It is strictly forbidden to disassemble the butterfly valve of the disintegrated telescopic flange at the pipeline construction site; it is strictly forbidden to lengthen and shorten the telescopic butterfly valve repeatedly at the site.
2. The pipes at both ends of the telescopic valve must be concentric, and the two flange surfaces on the pipe must be parallel;
3. Flange fixing bolts should be tightened symmetrically, please do not forcibly tighten flange fixing bolts unilaterally;
4. The telescopic tube is installed behind the valve;
5. The expansion part of the expansion valve shall not be installed at the corner of the pipeline or at the end of the pipeline.
6. The telescopic flange butterfly valve must be placed flat before installation, and do not bump it at will;
7. The structural length of the telescopic flange butterfly valve is the minimum length when it leaves the factory, and when installed, it is pulled to the installation length (ie the design length);
8. When the length between the pipelines exceeds the installation length of the telescopic butterfly valve, please adjust the pipeline interval and do not force the telescopic valve to avoid damage to the telescopic valve;
9. The butterfly valve of the telescopic flange butterfly valve can be installed at any position. When used for temperature compensation, after the installation of the pipeline, brackets should be added along the two ends of the pipeline axis to prevent the telescopic valve telescopic tube from being pulled out. The support force of the bracket is calculated according to the following formula , It is strictly forbidden to remove the bracket during operation;
10. The telescopic flange butterfly valve does not do temperature compensation. At the same time, it is only used for installation, replacement, and maintenance. When the valve is convenient for use, it can be limited by bolts, and the telescopic flange butterfly valve can be clamped symmetrically to prevent the telescopic tube from being pulled out and damaging the telescopic butterfly valve and piping devices or buildings. Things. The bolt diameter can be calculated according to the flange bolt diameter, its bolt strength and test pressure and pipeline tension, according to the above formula. The limit bolts are strictly prohibited to be removed during operation (bolts are provided separately).

TH Valve is a professional manufacturer of butterfly valve, gate valve, check valve, globe valve, knife gate valve, ball valve with API, JIS, DIN standard, used in Oil, Gas, Marine industry, Water supply and drainage, fire fighting, shipbuilding, water treatment and other systems, with Nominal Diameter of DN50 to DN1200, NBR/EPDM/VITON, Certificates & Approvals: DNV-GL, Lloyds, DNV, BV, API, ABS, CCS. Standards: EN 593, API609, API6D

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Flange telescopic butterfly valve application | advantages and disadvantages | installation instructions

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