manufacturer Archives

Introduction to basic knowledge of gate valve

August 16, 2021

The gate valve is one of the important pipe fittings in the pipeline for conveying fluid media. The gate valve is mainly used for cutting off the medium. It can only be fully opened or fully opened, and cannot be used for flow adjustment. Its opening and closing part is a gate. The movement direction of the gate is perpendicular to the direction of the fluid. The gate has two sealing surfaces. When the gate valve is closed, the sealing surface of the gate can be pressed to the other side only by the pressure of the medium. The valve seat is sealed, which is self-sealing. Most gate valves are forcibly sealed, that is, when the valve is closed, it needs to rely on the external force of the medium to force the gate to the valve seat to ensure the tightness of the sealing surface.

BS5163-BB-NRS-soft seated-wedge gate valve-DN200-PN16-handwheel (1)nt

The gate valve has a wide range of uses, and has applications in petroleum, petrochemical, chemical, metallurgical, electric power, water conservancy, urban construction, fire protection, coal and other industries. Gate valve is also a valve with distinct advantages and disadvantages.

Advantages of gate valve
1. After the gate valve is opened, the medium channel inside the valve body is straight, without any obstruction, and the flow resistance is very small.
2. When opening and closing, the movement direction of the gate valve is perpendicular to the flow direction of the medium, the pressure is small, and the opening and closing is labor-saving.
3. The height of the gate valve is large, so the opening and closing time is longer, and water hammer is not easy to occur.
4. The two sides of the gate valve channel are symmetrical, and the medium can flow in any direction on both sides, so the installation of the gate valve is very convenient.
5. The length of the structure is short, the manufacturing process is good, and the scope of application is wide.

Disadvantages of gate valve
1. The sealing surface of the gate valve is very easy to wear, which affects the service life of the valve, and it is troublesome to maintain.
2. The structure of the gate valve is more complicated, and it is also troublesome to process, especially the sealing surface on the gate seat is not easy to process, and there are many parts, so the price is more expensive.
3. The overall size is large, a certain amount of space is required for opening, and the opening and closing time is long.

Precautions for installation and use of gate valve
1. Handwheels, handles and transmission mechanisms are not allowed to be used for lifting, and collisions are strictly prohibited.
2. The double sluice gate valve should be installed vertically, that is, with the hand wheel facing upwards.
3. The gate valve with bypass valve should be opened before opening, the purpose is to balance the pressure difference between the inlet and outlet.
4. The gate valve with transmission mechanism should be installed strictly in accordance with the product manual.
5. If the gate valve is switched frequently, lubricate at least once a month.
6. The gate valve is not suitable for regulating or throttling.

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

Installation and Maintenance of Butterfly Valve

August 13, 2021

The butterfly valve has become one of the most widely used valves. Although it is only a small part on the fluid pipeline, it has a very large effect. The installation and maintenance of butterfly valves is a science. The correct installation of butterfly valves is the first step to ensure the normal operation of the pipeline, and subsequent maintenance has a positive effect on prolonging the service life of butterfly valves and reducing production costs. This article will talk about the installation and maintenance of butterfly valves for you.

lug type butterfly valve, ductile iron, center lined,

The working principle of butterfly valve
The working principle of the butterfly valve is that the valve stem drives the rotation of the butterfly plate to complete the opening and closing, and the rotation angle is 90°; changing the deflection angle of the butterfly plate can control the flow of the medium. Common butterfly valves include wafer butterfly valves and flange butterfly valves. Wafer type butterfly valve uses double-head bolts to connect the valve between two pipeline flanges. Flange type butterfly valve has flanges on the valve, and bolts are used to connect the flanges at both ends of the valve to the pipeline flanges. Butterfly valve allows fluid speed: liquid ≤ 4.5 m/s, gas ≤ 20 m/s.

Installation direction and position of butterfly valve

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

Butterfly valves generally have no direction requirements. If required, it should be determined according to the rotation angle of the butterfly valve and the working principle of the pneumatic actuator. The best position of the valve installed on the horizontal pipeline is vertical installation, and vertical downward is not allowed. The valve installation position must be easy to operate; timely installation is temporarily difficult, and the operator must also consider the long-term work of the operator. It is best to keep the valve hand wheel flush with the chest, generally 1.2 meters away from the operating floor, so that it is easier to open and close the valve. The handwheel of the floor valve should be upward, not tilted. For valves that lean against the wall against the equipment, leave room for the operator to stand on. It is necessary to avoid operating from the sky, especially acid-base, toxic media, etc., otherwise it is very unsafe.

Maintenance work of butterfly valve
When maintaining the butterfly valve, pay attention to whether there is water in the pneumatic actuator mechanism. In the wet season, the accumulation of water in the air compressor tank makes the transmission mechanism or the transmission shaft sleeve rust, and the accumulation of water in the air compressor tank in the cold winter weather enters the pneumatic actuator mechanism and freezes, causing aerodynamics. When the actuator is operated, the torque is too large, which damages the transmission components and cannot be operated manually; if the actuator is operated forcibly, the internal parts of the actuator will also be damaged. During maintenance, the discharge valve in the air compressor tank should be opened from time to time and the internal water should be taken out. For butterfly valves with hand wheels, open the turbine box cover to check whether the lubricating oil is normal within 6 months of operation, and keep a proper amount of lubricating oil.

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

resilient seated butterfly valve vs metal seated butterfly valve

August 12, 2021

Butterfly valve, also called flap valve, has a wide range of uses. It is generally installed on pipelines that transport various corrosive and non-corrosive fluid media in gas, natural gas, liquefied petroleum gas, cold and hot air, chemical smelting and other engineering systems for adjustment. And cut off the flow of the medium. There are many types of butterfly valves, and different types of butterfly valves have different uses. Butterfly valves are classified according to the sealing form and can be divided into soft-sealed /resilient seated butterfly valves and hard-sealed /metal seated butterfly valves. Although there is only one word difference between the two types of butterfly valves, they are very different in terms of structural materials and application fields. This article will analyze the difference between a resilient seated butterfly valve and a metal seated butterfly valve.

wafer type butterfly valve, EPDM seat (10)

The main difference between resilient seated butterfly valve and metal seated butterfly valve lies in the sealing surface:

The two sides of the sealing pair of the resilient seated butterfly valve are made of metal materials on one side, and the other side is made of elastic non-metallic materials, generally rubber or tetrafluoroplastics. The combination of this sealing material makes the resilient seated butterfly valve have good sealing performance, but it is not resistant to high temperature, easy to wear, and has a short service life.

Both sides of the sealing pair of the metal seated butterfly valve are made of metal materials. The metal-to-metal seal makes the sealing performance of the metal seated butterfly valve normal, but it is resistant to high temperature, pressure and abrasion, and has a long service life.

The seat of the soft sealing butterfly valve is made of rubber or tetrafluoroplastic. It has excellent sealing performance and can achieve zero leakage, but it has a relatively short service life and is not resistant to high temperatures. It is also not suitable for some highly corrosive media pipelines. The sealing seat of the hard-sealed butterfly valve is made of metal material, and the sealing performance is

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

relatively poor, but it is wear-resistant and has strong pressure resistance. It is suitable for strong corrosive medium pipelines.

In addition to the difference in the sealing surface, the difference between the resilient seated butterfly valve and the metal seated butterfly valve is as follows:

Resilient seatedbutterfly valves are mostly center-line type. Metal seatedbutterfly valves are mostly single eccentric, double eccentric and triple eccentric.
The Resilient seatedbutterfly valve is suitable for normal temperature environment. metal seatedbutterfly valves are well adapted to low temperature, normal temperature and high temperature environments.
The Resilient seatedbutterfly valve is suitable for low pressure and normal pressure environment. metal seated butterfly valveis not only suitable for low pressure and normal pressure, but also suitable for medium and high pressure working environment.
As mentioned above, the sealing performance of the Resilient seatedbutterfly valve is better than that of the metal seatedbutterfly valve, but now in order to adapt the hard sealing butterfly valve to more working conditions, it has a special process
The Resilient seatedbutterfly valve is suitable for the two-way opening and closing of the ventilation and dust removal pipeline and the adjustment of water treatment, light industry, petroleum, chemical and other industries. metal seatedbutterfly valves are mostly used in heating, gas, gas, oil, acid and alkali environments.

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

Difference between NRS gate valve and RS gate valve

August 11, 2021

NRS gate valve, means Non-rising Stem gate valve; RS gate valve, means Rising stem gate valve. you can see the difference in appearance on below photos.

Gate valve is one of the most common valves in piping systems. Because it can only be fully open and fully open, gate valves are commonly used when the fluid medium in the pipeline needs to be cut off. The operation of the gate valve does not need to be so frequent. Gate valves are widely used because they can be divided into many types. Different gate valve types have certain differences in use. This article mainly analyzes the difference between the RS gate valve and the NRS gate valve.

rising stem gate valve-RS-BB OS&Y (3)

Gate valves are classified according to the type of stem, which can be divided into two types: RS gate valve and NRS gate valve. The two are different in transmission mode, valve body structure, installation space, application range, etc.
1. The difference in the transmission mode. The transmission mode of the RS gate valve is that the handwheel drives the nut to rotate in place, and the valve stem rises and falls linearly. Through the threaded drive of the valve stem and the steering wheel, the valve flap is raised and lowered to complete the switch; the NRS gate valve is manual The wheel drives the valve stem to rotate. The hand wheel and the valve stem are connected together and relatively immovable. There are threads in the gate, and the valve stem rotates at a fixed point to drive the gate to rise and fall.
Second, the difference in structure, the structure of the rising stem gate valve is that the stem nut is on the bonnet or bracket. When the gate is opened and closed, the stem nut is rotated to realize the lifting of the stem. The structure of the NRS gate valve is that the stem nut is in the valve body and is in direct contact with the medium; when opening and closing the gate, it is realized by rotating the stem.

DIN-F4-BB-NRS-soft seated-wedge gate valve-DN100-PN16-copper holding ring-handwheel (3)

Third, the difference in installation space, the rising stem gate valve requires a larger installation space due to the stem; the height of the NRS gate valve is small, and it will not take up too much space during installation.
Fourth, the difference in application scope, the structure of the rising stem gate valve is beneficial to the lubrication of the stem, and the degree of opening and closing is obvious; the stem thread of the NRS stem gate valve is not only unable to be lubricated, but it is directly corroded by the medium and is easily damaged. Therefore, the RS gate valve is more The NRS stem gate valve has a wider range of applications.

The above is the difference between the RS gate valve and the NRS gate valve. Next, I will introduce you a little common sense, how to judge the RS gate valve and the NRS gate valve:

The stem of the RS gate valve drives the gate to move up and down together. The drive thread on the stem is outside the valve body. The opening and closing and position of the gate can be intuitively judged according to the movement direction and position of the stem; the drive thread of the NRS gate valve is located on the valve. Inside the body, during the opening and closing process, the valve stem only rotates, the gate moves up and down in the valve body, and the valve opens and closes until the steering wheel does not rotate.

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

Working principle and characteristics of triple eccentric butterfly valve

August 9, 2021

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)

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 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

Gate valve structure diagram and working principle

August 4, 2021

Gate valve structure; Working principle of gate valve
Gate valve /stop valve structure:
The gate valve refers to a valve in which the gate closing member moves along the vertical direction of the center line

rising stem gate valve-open and closed position

of the passage. Generally, it consists of valve body, valve seat, valve stem, gate, valve cover, and sealing ring. It can be transformed into a variety of electric gate valves and pneumatic gate valves by equipping transmission devices and gate valves. It is used for full-open and full-close cut-off, and cannot be used for adjustment and throttling. ,
Gate valve structure diagram Gate valve working principle:
The gate of the gate valve moves linearly with the valve stem. Usually there is a trapezoidal thread on the lifting rod. Through the nut on the top of the valve and the guide groove on the valve body, the rotary motion is changed into linear motion, that is, the operating torque is changed. For operating thrust. When the gate valve is closed, the sealing surface can only rely on the medium pressure to seal, that is, rely on the medium pressure to press the sealing surface of the gate to the valve seat on the other side to ensure the sealing of the sealing surface, which is self-sealing. Most gate valves adopt forced sealing, that is, when the valve is closed, the gate must be forced against the seat by external force to ensure the sealing performance of the sealing surface.

gate valve working diagram-3D GIF animated presentation

When the gate valve is opened, when the lift height of the gate is equal to 1:1 times the valve diameter, the fluid passage is completely unblocked, but this position cannot be monitored during operation. In actual use, the apex of the valve stem is used as the mark, that is, the unmovable position, as its fully open position. In order to take into account the lock-up phenomenon caused by temperature changes, it is usually opened to the top position, and then rewind 1/2-1 circle, as the position of the fully open valve. Therefore, the fully open position of the valve is determined by the position of the gate (ie stroke).

Non-rising stem(NRS) and rising stem(RS) gate valve

August 4, 2021

structures and differences of Non-rising stem(NRS) gate valve and rising stem(RS) gate valve
RS gate valve structure picture, NRS gate valve structure picture

non-rising stem gate valve-open and close position

RS gate valve and NRS gate valve are different from the transmission mode. RS gate valve is a handwheel that drives a nut to rotate in place, and the stem is linearly raised and lowered to complete the switch; NRS gate valve is a handwheel that drives the stem to rotate, and there are threads in the gate. Nut) to move up and down to complete

the switch.
Structural principle of gate valve:
1. NRS gate valve structure: The stem nut is in the valve body and is in direct contact with the medium. When opening and closing the gate, it is realized by rotating the valve stem.
2. RS gate valve structure: the stem nut is on the bonnet or bracket. When opening and closing the gate, the stem nut is rotated to realize the lifting of the stem.

DIN-F4-BB-NRS-soft seated-wedge gate valve-DN100-PN16-copper holding ring-handwheel (3)

The difference between RS gate valve and NRS gate valve:
1. RS gate valve can see the screw, but NRS can not see the screw;
2. The RS gate valve raises or lowers the disc through the threaded transmission of the valve stem and the steering wheel; when the NRS gate valve is switched on and off, the steering wheel and the valve stem are connected and relatively immobile. It drives the valve through the rotation of the valve stem at a fixed point. The flap is lifted up and down to complete the opening and closing;
3. The transmission thread of the NRS gate valve is located inside the valve body. During the opening and closing process, the valve stem only rotates, and the gate is raised and lowered in the valve body; the valve stem of the RS gate valve drives the gate to rise and fall together, and the drive thread on the valve stem Outside the valve body, the opening and closing and position of the gate can be intuitively judged according to the movement direction and position of the valve stem;

rising stem gate valve-RS-BB OS&Y (3)

4. The height of the NRS gate valve is small; the RS gate valve requires a larger installation space;
5. The structure of the RS gate valve is beneficial to the lubrication of the valve stem, and the degree of opening and closing is obvious; the thread of the valve stem of the NRS gate valve is not only unable to be lubricated, but it is directly corroded by the medium and is easily damaged. Therefore, the RS gate valve is more widely used.

Representation method of electric gate valve model

July 27, 2021

Representation method of electric gate valve model; model name modification method; code name modification method
The electric gate valve is composed of an electric actuator and a gate valve body. The gate plate is controlled by the

gate valve (1)

power supply pressure to perform up and down linear operation to connect or close the fluid medium in the pipeline. The applicable pressure, temperature and caliber range are large, and it is especially suitable for Medium and large diameter pipes. Electric gate valves can be divided into various series. The actuators have on-off type and intelligent type, and the structure is very changeable. When selecting the type, the user should be familiar with the electric gate valve model preparation instructions to avoid selecting the wrong model, placing the wrong order and technology Unknown parameters caused problems such as exchange and return.
Electric gate valve model preparation instructions are mainly for the detailed explanation of the additional conditions of the gate valve, drive mode, connection form, structural feature, sealing material, pressure level and valve body material. Other customized or special product models are not applicable to this method. , Additional explanation is required.
The method of preparing the model of the electric gate valve:
Additional code for gate valve: WZ means bellows gate valve, DZ cryogenic gate valve, NKZ vacuum gate valve, PZ knife gate valve;
Type of gate valve: Z;
Drive mode: manual without code (usually omitted according to regulations), 2 electro-hydraulic, 3 worm gear, 5-bevel gear transmission, 6 pneumatic, 9-electric;
Connection mode: 4 flange connection, 6 welding, 7 pair clip type;
Structural form: 0 elastic gate, 1 open-rod wedge-type single gate, 2-open-rod wedge-type double gate, 3-open-pole parallel single gate, 4-open-pole parallel double gate, 5 concealed Rod wedge single gate, 6 concealed rod wedge double ram, 7 concealed rod parallel single ram, 9 concealed rod parallel double ram;
Sealing material: W valve body is directly processed, T alloy, X rubber, F fluoroplastic, H-Cr stainless steel, Y cemented carbide, M Monel alloy;
Pressure rating: PN1.0-32Mpa, 16=1.6MPA means the pressure is 16 kg, 150LB-1500LB means the American

standard pound pressure, 5-63K means the Japanese pressure;
Valve body material: Z-gray cast iron, Q ductile iron, T alloy, C carbon steel, P stainless steel 304, R stainless steel 316, V chromium molybdenum vanadium steel.

electric stainless steel gate valve

Description of electric gate valve model preparation:
Z941H-16P Stainless steel electric flange gate valve1. Z: represents gate valve;
2. 9: indicates that the transmission mode is electric;
3. 4: The connection method is flange connection;
4. 1: The structure is an open pole wedge single gate;
5. H: The sealing material is stainless steel;
6. 16: Indicates that the nominal pressure is 1.6MPa;
7. P: indicates that the valve body material is 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

The difference between globe valve and gate valve

July 23, 2021

The difference between globe valve and gate valve, The difference between gate valve and globe valve

From the structure:
The length of the gate valve is shorter than that of the stop valve, and the height is higher than that of the stop valve. The installation of the rising stem gate valve should pay attention to the height. This should be paid attention to when the installation space is limited. The gate valve can be tightly closed with the sealing surface depending on the medium pressure, so as to achieve the effect of no leakage. When opening and closing, the valve core and the valve seat sealing surface are always in contact and rub against each other, so the sealing surface is easy to wear. When the gate valve is close to closing, the pressure difference between the front and rear of the pipeline is large, which makes the sealing surface wear more serious.

globe valve structure diagram

gate valve structure diagram

In principle:
The difference between the globe valve and the gate valve in principle is that the globe valve is a rising stem type, and the hand wheel rotates and rises together with the stem. In the gate valve, the hand wheel rotates and the valve stem moves upward. The flow rate is different, the gate valve is required to be fully open or fully closed, but the stop valve is not required. The shut-off valve has specified inlet and outlet directions; the gate valve has no inlet and outlet direction requirements.
Schematic diagram of gate valve Schematic diagram of globe valve
Explanation: The flow part of the gate valve is also the same as the straight pipe, but a gate is set in the pipe. If the gate is lifted up, the door will be fully opened, and the fluid of the stop valve will turn inside the valve. A 180-degree bend, usually the fluid enters from one side of the valve and after entering the valve, the fluid flows upward at a 90-degree angle, and then flows through the upper part of the valve body and then turns a 90-degree flow out, just as the fluid flows inside the valve. A cover is added to the upper outlet, the cover is closed and the door is closed, and the valve is opened when the cover is opened.

From the flow up:
The shut-off valve is low in and high out. From the outside, it is obvious that the pipeline is not on the horizontal line of one phase. The gate valve flow path is on a horizontal line. The stroke of the gate valve is larger than that of the stop valve.

globe cut-off valve working diagram-3D GIF animated presentation-flow direction

Explanation: From the perspective of flow resistance, the flow resistance of the gate valve is small when it is fully opened, and the flow resistance of the load stop valve is large. The flow resistance coefficient of ordinary gate valve is about 0.08~0.12, the opening and closing force is small, and the medium can flow in two directions. The flow resistance of ordinary globe valves is 3-5 times that of gate valves. When opening and closing, it needs to be forced to close to achieve the seal. The valve core of the stop valve does not contact the sealing surface when it is completely closed, so the wear of the sealing surface is very small. The stop valve that needs to add an actuator due to the main flow force should pay attention to the torque control mechanism Adjustment.

gate valve working diagram-3D GIF animated presentation-flow direction

From the installation:
1. The flow direction of the gate valve is the same when entering from both sides.
2. There are two ways to install the shut-off valve. One is that the medium can enter from below the valve core. The advantage is that the packing is not stressed when the valve is closed, which can prolong the service life of the packing and can be piped in front of the valve. Under pressure, the packing should be replaced; the disadvantage is that the driving torque of the valve is relatively large, which is about 1 times that of the upper flow, and the axial force on the valve stem is large, and the valve stem is easy to bend. Therefore, this method is generally only suitable for small-diameter stop valves (below DN50). For stop valves above DN200, the medium flows in from above. (The electric shut-off valve generally adopts the way that the medium enters from above.) The shortcoming of the medium entering method from above is just the opposite of that of the downward entering method.

From the sealing surface:
The sealing surface of the globe valve is a small trapezoidal side of the valve core (see the shape of the valve core for details). Once the valve core falls off, it is equivalent to closing the valve (if the pressure difference is large, of course the closing is not tight, but the anti-reverse effect is not bad). The gate valve is sealed by the side of the valve core gate plate, the sealing effect is not as good as the stop valve, and the valve core will not be closed like the stop valve when the valve core falls off.

You can check the detailed data sheet /specification /structure diagram /sizes /materials of

globe valve on:https://www.tanghaivalve.com/wp-content/uploads/2021/05/500-api-jis-globe-valve-cast-steel-forged-steel.pdf gate valve: https://www.tanghaivalve.com/wp-content/uploads/2021/05/301-data-sheet-gate-valve-th-valve.pdf

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

Gate valve model meaning and representation method

July 22, 2021

Gate valve model representation method | Gate valve model meaning
Explanation of the meaning of the gate valve model:

pneumatic gate valve (3)

Gate valve is one of the more common types of shut-off valves. It is generally suitable for full-open or full-close two-position operation control. It is mainly used to close the medium in the pipeline. It is usually called a cut-off valve or a blocking valve. With the increase in demand for valves and the expansion of demand in the machinery industry, gate valves have become an indispensable part of modern industrial control systems. For more and more complex working conditions and harsh use requirements, the correct selection of gate valve models is related to the adaptability of the pipeline medium and an important guarantee for the safety of the working conditions. The user should have a detailed understanding of the method of preparing the gate valve model to avoid problems such as selecting the wrong model, placing the wrong order, and unclear technical parameters resulting in replacement and return.
This compilation method is the representation method of the standard gate valve model in my country. It mainly explains in detail the additional conditions of the gate valve, drive mode, connection form, structural feature, sealing material, pressure level and valve body material. Other customized or special product models are not applicable to this method and need to be explained separately.
The method of formulating and expressing gate valve model:
Additional code for gate valve: WZ means bellows gate valve, DZ cryogenic gate valve, NKZ vacuum gate valve, PZ knife gate valve;
Type of gate valve: Z;
Drive mode: manual without code (usually omitted according to regulations), 2 electro-hydraulic, 3 worm gear, 5-bevel gear transmission, 6 pneumatic, 9-electric;
Connection mode: 4 flange connection, 6 welding, 7 pair clip type;
Structural form: 0 elastic gate, 1 open-rod wedge-type single gate, 2-open-rod wedge-type double gate, 3-open-pole parallel single gate, 4-open-pole parallel double gate, 5 concealed Rod wedge single gate, 6 concealed rod wedge double ram, 7 concealed rod parallel single ram, 9 concealed rod parallel double ram;
Sealing material: W valve body is directly processed, T alloy, X rubber, F fluoroplastic, H-Cr stainless steel, Y cemented carbide, M Monel alloy;
Pressure rating: PN1.0-32Mpa, 16=1.6MPA means the pressure is 16 kg, 150LB-1500LB means the American standard pound pressure, 5-63K means the Japanese pressure;
Valve body material: Z-gray cast iron, Q ductile iron, T alloy, C carbon steel, P stainless steel 304, R stainless steel 316, V chromium molybdenum vanadium steel.

Knife-gate-valve-1-

Example of preparing gate valve model:
PZ973H-16C Electric Wafer Type Knife Gate Valve

1. PZ: stands for knife gate valve;
2. 9: indicates that the transmission mode is electric;
3. 7: The connection method is a clip-on connection;
4. 3: The structure is an open pole parallel single gate;
5. H: The sealing material is stainless steel;
6. 16: Indicates that the nominal pressure is 1.6MPa;
7. C: Indicates that the valve body material is carbon 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

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