china factory Archives

Pneumatic butterfly valve model name coding method

August 3, 2021

Pneumatic butterfly valve model preparation method, code naming method, only in China
Pneumatic butterfly valve is one of the most common valves in industrial piping systems. It has the functions of switch cut-off, proportional adjustment, and emergency cut-off. It also has rapid switching, simple structure and

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

easy maintenance. It is used more and more on low-pressure large and medium-diameter pipelines. ! However, due to the various connection methods and structural forms of pneumatic butterfly valves, many people are often uncertain when choosing butterfly valve models. In order to reduce this situation, our company provides pneumatic butterfly valve model compilation instructions for everyone. Reference and understanding!
Pneumatic 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! To
Pneumatic butterfly valve model representation method:
Additional codes for pneumatic 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;
Code of connection mode: 4 flange type, 6 welding, 7 pair clamp type; Structure code: 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. The above are common butterfly valve related codes. For products that need to be customized due to special working conditions, they can be selected according to the design plan.
Pneumatic butterfly valve model compilation instructions:

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

D673H-16C Stainless steel pneumatic wafer triple eccentric butterfly valve
D: Represents butterfly valve;
6: Indicates that the transmission mode is pneumatic;
7: The connection method is a wafer 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: Electric 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

electric fluorine-lined butterfly valve vs electric metal seated butterfly valve

August 2, 2021

The difference between electric fluorine-lined butterfly valve and electric hard seal butterfly valve
Electric butterfly valve is one of the most commonly used valves in industrial pipelines in recent years. In addition to ordinary opening and closing, it can also be used to adjust and control the pressure, flow, temperature and other parameters of various water, liquid, gas and other fluids. An important execution unit in the field of automation control, is widely used in chemical, electric power, petroleum, metallurgy, steam, environmental protection, fire-fighting systems and other occasions! In addition, there are many types of electric butterfly valves and various control modes, which can meet the requirements of various working conditions!

Fluorine lined butterfly valve-PTFE-WAFER (10)

Electric fluorine-lined butterfly valves and electric hard-sealed butterfly valves are the two most commonly used types of butterfly valves. The applicable medium and pressure temperature are completely different! But many people’s choice between the two often seems a bit uncertain! In the simplest terms, the two control modes are the same, the difference is the sealed structure. The electric fluorine-lined butterfly valve is suitable for corrosive media, but it can only be used at room temperature and pressure. The electric hard seal butterfly valve can be used for various pressures. temperature range! The detailed differences are as follows:
Electric fluorine-lined butterfly valve Electric hard-sealed butterfly valve
1. From the structure:
The hard sealing butterfly valve refers to that both sides of the sealing pair are made of metal materials or other harder materials. 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;

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

2. From the sealing performance:
The advantage of soft-sealed fluorine-lined butterfly valve is good sealing performance, but the disadvantage is that it is easy to age, wear, and has a short service life. The hard seal 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 environment, and 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 point of view:
As for manufacturing, from a principle point of view, there is little difference between the two, mainly the difference in valve seats. The soft-seal fluorine-lined butterfly valve is a non-metallic structure, and the hard-seal butterfly valve is a metal structure. The hardness relationship between metals and the workmanship must be considered. Situation, what medium to go and so on.
Related knowledge: Working principle diagram of electric butterfly valve Selection of electric wafer butterfly valve and flange 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, API

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

electric wafer butterfly valve vs electric flange butterfly valve

July 27, 2021

The difference and selection of electric wafer butterfly valve and electric flange butterfly valve
As one of the most common valves in pipelines, electric butterfly valves are used to realize the on-off and flow control of various media in the pipeline system. They have been widely used in many fields such as petroleum, chemical industry, metallurgy, and hydropower. application. Then in the commonly used electric butterfly valve, it can be

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

divided into two kinds, electric wafer butterfly valve and electric flange butterfly valve, and these two kinds of valves have their own characteristics, and they are not the same in performance. They can be used in Different industries.

For these two kinds of valves, in addition to the different structural forms, if they are under the same parameters, the biggest difference is that the connection method is different, that is, the installation form is different, which depends on the site working conditions!

The difference between electric wafer butterfly valve and electric flange butterfly valve:
The thickness of the electric wafer butterfly valve is relatively thin compared to the flanged butterfly valve. There are no flanges at both ends of the valve body, but only a few guide bolt holes. The valve uses a set of bolts/nuts to connect with the flange of the pipe end, which is generally applicable. It is used in places where the space is relatively narrow or the pipeline is restricted. The advantage is that it is more convenient to disassemble, the valve cost is lower, and the space is small, but the disadvantage is that one sealing surface has a problem, and both sealing surfaces have to be disassembled!
Electric flange butterfly valve has flanges at both ends of the valve body, which are connected with pipeline flanges. Compared with wafer butterfly valves, the sealing performance is more reliable. It is generally used in places with larger diameters or higher pressures, but the cost is relatively good.

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

Choice between the two:
However, there are still some things to pay attention to in the design. For example, wafer type valve bolts are generally relatively long. Under high temperature conditions, the expansion of the bolts may cause leakage, so it is not suitable for large pipe diameters under high temperature conditions. . Another example is the wafer butterfly valve generally cannot be used in the end of the pipeline and downstream needs to be disassembled, because when the downstream flange is removed, the wafer valve will fall off, in this case, it must be shortened separately. The flange type butterfly valve does not have the above problems, but the cost will be higher.
Related Electric butterfly valve series products View other 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

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

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

Selection and application of eccentric butterfly valve

June 23, 2021

Selection and application of eccentric butterfly valve
The advantages of eccentric butterfly valves and other butterfly valves are very prominent, so they are widely used in all aspects of life and work to meet various requirements. Moreover, with the continuous development of eccentric sealing butterfly valve technology, the space for its use becomes more and more extensive. TH valve company can produce double eccentric butterfly valve and triple eccentric butterfly valves, with good quality and reasonable prices.

Double eccentric-wafer butterfly valve-D372F-150lbP-stainless steel (1)

Application of double eccentric sealing butterfly valve
The double eccentric sealing butterfly valve adopts an eccentric structure design. The main structure of the valve is composed of valve body, butterfly plate, valve seat, valve stem and transmission mechanism. The valve seat adopts a detachable structure and can be based on the physical and chemical properties of different media. Corresponding corrosion-resistant, light-resistant, and aging-resistant materials are selected, which can be widely used in fluid pipelines such as water supply and drainage, sewage, construction, air conditioning, petroleum, chemical, food, medicine, textile, papermaking, hydropower, shipbuilding, metallurgy, energy systems, etc. Used as a regulating and intercepting device. The double eccentric butterfly valve usually uses tetrafluoroethylene material as its sealing seat, and can also use metal sealing seat to expand its application in the high temperature field. However, the seal of the double eccentric butterfly valve with metal sealing seat is still a positional sealing structure, that is, the sealing surface of the butterfly plate and the seat is in line contact, so it cannot withstand high pressure, and it will inevitably lead to greater leakage when used in a high pressure system. Therefore, double eccentric butterfly valves with metal seal seats should be avoided as far as possible in high-pressure or tight shut-off systems.

Application of triple eccentric sealing butterfly valve
The triple eccentric butterfly valve, as the crystallization of the latest technology of valves, takes advantage of the advantages of various valves and avoids the shortcomings of various valves, and has attracted more and more

cryogenic triple offset butterfly valve 1

attention from users and designers. The maximum pressure level can reach 2500 pounds, the standard caliber can reach 48 inches, and the clamp, lug, flange, ring connection, butt welding, jacket, various structural lengths, etc. can be corresponded, due to the room for material selection Very large, high and low temperature, various acids, alkalis and other corrosive media can also respond freely. Especially in the aspect of large diameter, with its zero leakage advantage, it is constantly replacing the thick gate valve and ball valve in the shut-off valve. Similarly, with its excellent control function, it is also constantly replacing the bulky control valve. Shut-off valve. So far, triple eccentric sealing butterfly valves have been used in various important pipelines including China’s oil and gas exploration, offshore platforms, petroleum refining, petrochemicals, inorganic chemicals, energy power generation and other major industrial fields such as process control. In actual engineering, if the working pressure of the system is not less than 1.0 MPa or in important parts that need to be opened frequently, triple eccentric butterfly valves can be used.
Related knowledge: common sense of eccentric butterfly valve
Related products: Electric triple eccentric butterfly valve Pneumatic triple eccentric 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

Vulcanized vs soft seated/back-up butterfly valve

June 17, 2021

The difference between rubber-lined butterfly valve and rubber butterfly valve (illustration)
The difference between a rubber-lined butterfly valve and a rubber butterfly valve, and the difference between a rubber-lined butterfly valve and a plastic-lined butterfly valve. The rubber-lined butterfly valve uses a high-temperature method to vulcanize the rubber and the valve body into one body. It has very high corrosion resistance and is generally used. To control some corrosive fluids with strong acidity and alkalinity. The rubber butterfly valve is a butterfly valve whose seal is a rubber seal, which is generally called a valve seat, and is separately installed into a whole.

Fluorine lined butterfly valve-PTFE-WAFER (8)

At normal temperature, the abrasion resistance of natural soft rubber is much better than that of nitrile rubber, but their high temperature resistance is the highest limit within 80 degrees, and it is not suitable for use if it exceeds.
The difference between a fully lined butterfly valve and a half lined butterfly valve:
1. Semi-lined butterfly valve means: the butterfly valve is not lined with rubber, but the place where the butterfly valve is connected to the valve body is lined with rubber;
2. Fully lined butterfly valve means: the butterfly plate of the butterfly valve and the part connected with the valve body are lined with rubber. The difference between rubber-lined butterfly valve, fluorine-lined butterfly valve and plastic-lined butterfly valve: rubber-lined butterfly valve and fluorine-lined butterfly valve are only one kind of plastic-lined butterfly valve.

wafer type butterfly valve (6)

The sealing materials in the rubber-lined butterfly valve are:
Applicable temperature of hard rubber NR: -10℃~85℃,
Applicable temperature of soft rubber BR: -10℃~85℃,
Suitable temperature for butyl rubber IIR: -10℃~120℃,
Applicable temperature of neoprene CR: -10℃~105℃;
The sealing materials in the fluorine-lined butterfly valve are:
Use temperature of polyperfluoroethylene FEP (F46): -85℃~150℃,
Polytetrachloroethylene PTFE (F4) operating temperature: -200℃~180℃,
Polytrifluoroethylene PCTEF (F3) operating temperature: -195℃~120℃,
Polypropylene: RPP operating temperature: -14℃~80℃,
Polyvinyl chloride: rigid) PVC service temperature: 0℃-55℃,
Polyvinylidene chloride PVDF (F2) operating temperature: -70℃~100℃,
Polyolefin: PO Operating temperature: -58℃~80℃.

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

Representation method of butterfly valve model

June 11, 2021

Representation method of butterfly valve model in China:
Butterfly valve model compilation instructions, butterfly valve model representation method, Butterfly valve model compilation instructions, butterfly valve coding /naming method:

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

There are countless types and specifications of butterfly valves for industrial pipelines. The increase in additional conditions for butterfly valves, the difference in connection methods, the upgrade of transmission methods, the changes in structural forms, and the increased requirements for temperature, pressure and corrosion resistance on materials are for the convenience of users in the industry. Have more knowledge about the correct selection of butterfly valves and the purchase of butterfly valves. For this purpose, Duoyi Valve provides the latest butterfly valve model compilation instructions, hoping to be helpful to the majority of users.

Butterfly valve model representation method:
Additional code of butterfly valve: 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 code: 4: flange type, 6: welding, 7: pair clamp type;

Structure code code: 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.
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.
Examples of butterfly valve model compilation:
D943H-16C electric triple eccentric 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;
C: Indicates that the valve body material is cast steel.
Related valve model: Valve model Globe valve model Check valve model Gate valve model Regulating valve model Ball valve model

See complete coding method on: Valve model establishment and meaning

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

Cryogenic valve principle |standard |illustration |selection

June 3, 2021

Principle of Cryogenic valve|Standard of Cryogenic valve|Selection of Cryogenic valve
The so-called cryogenic valve is a kind of altra-low temperature valve, as the name implies, is a valve suitable for working in cryogenic conditions. In the valve industry, valves that tend to -40°C are called cryogenic valves. Cryogenic valves are generally used in cryogenic systems such as liquid helium, liquid hydrogen, liquefied natural gas, and air separation. The medium used is liquid helium, liquid hydrogen, liquefied natural gas, liquid nitrogen, liquid oxygen and other cryogenic fluids. Under low temperature conditions, conventional metal hard seals and non-metal soft seals cannot meet the sealing requirements. In order to ensure that cryogenic valves can operate safely and reliably at low temperatures, there are some special considerations and requirements in the design and manufacture of cryogenic valves. see photo attached is a cryogenic triple offset butterfly valve.

triple offset valve parts-after-cryogenic process

Principle of ultra-low temperature valve: For valves used in ultra-low temperature conditions, the medium temperature is very low, and the metal materials will experience low temperature cold brittleness. The strength and hardness will be greatly improved, and the plasticity and toughness will be greatly reduced. This will directly affect the performance and safety of the valve. If an ordinary valve is used, the low temperature will freeze the packing in the valve stuffing box, and it will not be able to play a sealing role. In this way, the valve needs to be lengthened from the sealing seat on the bonnet to the bottom of the stuffing box. With sufficient isolation space and heat dissipation distance, the low-temperature medium in the valve body will not freeze the packing. As shown in the figure, the part marked with 175mm is the lengthened part.

In ultra-low temperature conditions, the valve stem and valve body can only adopt stuffing box or bellows structure. There are many restrictions on the use of bellows. Generally, the structure of the stuffing box seal is adopted. The stuffing box seal structure is simple to process and convenient to maintain. However, the sealing effect cannot be guaranteed under the condition of <-40℃, so the ultra-low temperature valves are all Keep the stuffing box as far away from the material as possible, and choose packing with low temperature characteristics.

Selection of ultra-low temperature valve:

cryogenic triple offset butterfly valve 1

Valve body: Ferritic stainless steel can be used when the temperature is higher than -100°C, austenitic stainless steel can be used when the temperature is lower than -100°C, copper alloy or aluminum alloy can be used for low-pressure and small-diameter valves. Stem: Made of austenitic stainless acid-resistant steel, it needs to be properly heat-treated to increase the tensile strength. At the same time, it must be hard chrome plated (coating thickness 0.04~0.06mm) or nitriding treatment to increase the surface hardness.

Gasket: When the working temperature is higher than -196℃ and the maximum low temperature working pressure is 3MPa, the asbestos rubber sheet made from long fiber can be used; when the working temperature is higher than -196℃ and the maximum low temperature working pressure is 5MPa, it can be used. Stainless steel spiral wound gasket with asbestos, stainless steel spiral wound gasket with PTFE, or stainless steel spiral wound gasket with expanded graphite.

Fasteners: when the temperature is higher than -100°C, the bolt material is Ni, Cr-Mo and other alloy steels, which need to be properly heat-treated to prevent thread bite; when the temperature is lower than -100°C, the bolt material can be austenitic Body stainless steel. The nut material is generally Mo steel or Ni steel, and the thread surface is coated with key disulfide.

Ultra-low temperature valve design standards:

1. Design: API6D, JB/T7749

2. Valve routine inspection and test: according to API598 standard.

3. Low temperature inspection and test of valve: According to JB/T7749.

4. Drive mode: manual, bevel gear drive and electric drive device.

5. Valve seat form: The valve seat adopts a welded structure, and the sealing surface is welded with cobalt-based hard alloy to ensure the sealing performance of the valve.

6. The ram adopts an elastic structure, and a pressure relief hole is designed at the pressure inlet end.

7. One-way sealing valve body is marked with flow direction mark.

8. The low-temperature ball valve, gate valve, and stop valve adopt a long neck structure to protect the packing.

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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