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Cleaning /Purge method of triple eccentric butterfly valve

As a new type of high-performance butterfly valve product, triple eccentric butterfly valve is widely used in heating, heating, gas supply, water supply pipeline and heating system of power station. After the triple eccentric butterfly valve is installed on the pipeline, it must be purged before work. After the butterfly valve and the pipeline are

triple offset butterfly valve-double flange- (5)

triple offset butterfly valve-double flange- (5)

installed, purging is required. The purging is to clean the pipeline and prevent the medium in the pipeline from affecting the normal operation of the valve. . What are the purge methods for the triple eccentric butterfly valve?

There are three common purging methods for triple eccentric butterfly valves: water flushing, air purging, and steam purging. Let’s introduce them one by one below.

Water flushing method:
1. Use clean water when flushing valves and pipes with water.
2. When flushing, use the maximum flow rate, and the flow rate of the water flow is not less than 1.5m/S.
3. The valve and the drainage branch of the pipeline must be flushed.
4. Water rinsing should be carried out continuously, until the color and transparency of the drain outlet are basically the same as the inlet water from the naked eye, it is qualified.
5. After the valves and pipelines have been flushed with water, if they are not put into production temporarily, the water inside should be completely drained to keep the valve body and pipeline dry.

Air purging method:
1. Air purging uses a large container in a large compressor to perform intermittent purging of valves and pipes. The purging pressure cannot exceed the design pressure of the vessel and pipeline.
2. When purging oil-free pipelines, the gas must not contain oil.
3. After air purging the pipeline, you can paste a white cloth or white painted wooden target board on the pipeline exhaust port where the valve is installed to check whether the pipeline is cleaned. After blowing for a few minutes, there is no rust on the white cloth. Other sundries such as dust are qualified.

Method of steam purging:
1. During steam purging, a temporary pipeline should be installed, which should be installed in accordance with the technical requirements of the steam pipeline.
2. The steam pipeline is used for purging the valves and pipelines with a large flow of steam, and the flow rate of the steam is not less than 30m/s.
3. Before steam purging, the pipes should be warmed up and the water in the valves and pipes should be drained. The pipes should be warmed up, drained in time, and the thermal displacement of the pipes should be checked.
4. The steam purging should be carried out in a cycle, and the sequence is heating-cooling-reheating.

TH Valve is a professional manufacturer of butterfly valvegate valvecheck valveglobe valveknife 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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Working principle and characteristics of triple eccentric butterfly valve

Triple eccentric butterfly valve, also named triple offset butterfly valve.

Nowadays, butterfly valves have been used in many industries. In the beginning, the butterfly valve was only used for the interception and communication of water media. The triple eccentric design enhances the function of the butterfly valve and has become one of the valves with excellent performance in industrial industrial pipeline equipment. The triple eccentric butterfly valve, as the name implies, is that three independent offsets are designed as valves. In reality, many people do not know which one is a triple-eccentric butterfly valve because of insufficient cognition. In this article, let’s talk about the working principle and characteristics of the triple-eccentric butterfly valve.

triple offset butterfly valve-double flange- (5)

triple offset butterfly valve-double flange- (5)

The working principle of the triple eccentric butterfly valve is that the valve body of the butterfly valve has a horizontal valve port connected to the pipeline in structure, and the valve port has a valve plate. The shaft is perpendicular to the valve port and penetrates the valve body and the valve plate. The edge of the valve plate is provided with an outer spherical surface, and the valve port is provided with a sealing surface that can be matched with the outer spherical surface. When the sealing surface and the outer spherical surface are matched and sealed, there is an eccentric distance a between the sealing line and the axis of the shaft, which is in the transverse center of the valve plate. The line is the eccentricity b between the center line of the valve port and the center line of the shaft, and there is an angle β between the connection line of the outer spherical surface and the center line of the valve port. This is the principle of the triple eccentric butterfly valve.
The triple eccentric butterfly valve cleverly puts the triple eccentricity on the valve plate, and adopts a partial outer spherical structure on the outer edge of the valve plate. This structure needs to be completed on a CNC machine with a self-designed simple fixture. The outer eccentric spherical surface is polished to reach a roughness of Ra0.4, the spherical surface is chrome-plated or made of Stellite alloy, and the hardness reaches HRC45-60.
Put the eccentric angle on the valve plate, and press the valve seat on the valve body with a pressing ring, which solves the difficulties encountered in the processing of ordinary triple eccentric butterfly valves. The valve body, valve plate and valve seat cannot be exchanged for pairing. Repair after damage A series of problems such as high cost, all parts are modularized, warehouse management is simple, processing is simple, maintenance is convenient, and the cost of spare parts is reduced.
The butterfly valve is suitable for making large-diameter valves. It can be widely used in the cutting of petroleum transportation pipelines, metallurgical steel plants, gas main pipeline adjustment and cutting, chemical smelting equipment medium adjustment and cutting, water treatment equipment inlet and outlet adjustment and shutdown, and cooling water in thermal power stations. System, natural gas, lye, sea water, acid and other industries.

The characteristics of the triple eccentric butterfly valve are as follows:
1. Simple structure, light weight, composed of only a few parts. easy to use.
2. After the valve plate is fully opened, the thickness of the butterfly plate is the only resistance for the medium to pass through the valve body. The pressure is small and the flow can be better controlled.
3. When the valve plate is closed, the specific pressure between the outer spherical surface of the valve plate and the sealing surface of the valve seat is generated by the driving torque applied to the shaft. Coupled with the elastic compensation of the M-type elastic valve seat, the sealing performance of the valve can be enhanced, and the service life is greatly improved.
Understand the working principle and characteristics of triple eccentric butterfly valve, then where can I buy high-quality triple eccentric butterfly valve products? of course, Tanghai valve.

TH Valve is a professional manufacturer of butterfly valvegate valvecheck valveglobe valveknife 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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electric fluorine-lined butterfly valve vs electric metal seated butterfly valve

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)

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

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 valvegate valvecheck valveglobe valveknife 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

Related news /knowledge: Classification and selection of fluorine-lined valves; Selection and application of eccentric butterfly valve; Fluorine-lined valve instructions | Installation instructions

Structural characteristics of metal hard seal butterfly valve

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

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 valvegate valvecheck valveglobe valveknife 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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Advantages and disadvantages of butterfly valve and structure diagram

Advantages and disadvantages of butterfly valve and structure diagram
The butterfly valve opening and closing part is a disc-shaped butterfly plate, which rotates around its own axis in the valve body to achieve opening and closing or adjustment. The butterfly valve is usually less than 900 from fully open to fully closed. The butterfly valve and the butterfly rod themselves are not self-locking. For the positioning of the butterfly plate, a worm gear reducer must be installed on the valve rod. The use of worm gear reducer can not only make the disc plate have self-locking ability, make the disc plate stop at any position, but also improve the operation performance of the valve.

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

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

The industrial butterfly valve is characterized by high temperature resistance, high applicable pressure range, large nominal diameter of the valve, the valve body is made of carbon steel, and the sealing ring of the valve plate uses a metal ring instead of a rubber ring. The large high temperature butterfly valve is made of steel plate welding, and is mainly used for flue ducts and gas pipes of high temperature media.
(1) Advantages of butterfly valve:
1. It is convenient and quick to open and close, labor-saving, low fluid resistance, and can be operated frequently.

Wafer and Lug type butterfly valve structures & parts

Wafer and Lug type butterfly valve structures & parts

2. Simple structure, small size and light weight.
3. Mud can be transported, and the accumulation of liquid at the pipe mouth is the least.
4. Under low pressure, good sealing can be achieved.
5. Good adjustment performance.
(2) Disadvantages of butterfly valves:
1. The working pressure and working temperature range are small.
2. Poor airtightness.
(3) Installation and maintenance of butterfly valve:
1. During installation, the valve disc should be stopped in the closed position.
2. The opening position should be determined according to the rotation angle of the butterfly plate.
3. For the butterfly valve with bypass valve, the bypass valve should be opened before opening.
4. The installation should be carried out according to the installation instructions of the manufacturer, and the heavy-weight butterfly valve should be installed with a firm foundation.
Related knowledge: the principle of butterfly valve structure

Double flange butterfly valve structure

Double flange butterfly valve structure

Related products: Electric butterfly valve Pneumatic butterfly valve

TH Valve is a professional manufacturer of butterfly valvegate valvecheck valveglobe valveknife 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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Fluorine-lined butterfly valve vs metal seated butterfly valve

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)

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)

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 valvegate valvecheck valveglobe valveknife 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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electric fluorine-lined butterfly valve vs electric metal seated butterfly valve;
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Classification and selection of fluorine-lined valves;

Selection and application of eccentric butterfly valve

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)

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

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 valvegate valvecheck valveglobe valveknife 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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Installation instructions of double eccentric butterfly valve;
Notes on selection and installation of butterfly valve

Cryogenic valve principle |standard |illustration |selection

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

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:

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 valvegate valvecheck valveglobe valveknife 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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