gate valve Archives

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

How many types of gate valves?

July 19, 2021

Types and classifications method of gate valves
Gate valve, also called slab valve, is mainly composed of valve body, bonnet, gate, valve stem, valve seat and sealing packing. It is one of the most common valve types in isolation valves. The main purpose of the gate valve is to cut off the fluid. For this reason, it is usually called a “cut off” valve or a “blocking” valve. There are many different structural forms of gate valves, and the types of sealing elements used in them are different. According to the

Socket ended resilient seated wedge gate valve-ductile iron (1)

structure of the sealing element, it can be divided into several different types.
Classified by valve stem:
According to the stem type, it can be divided into bright stem gate valve and dark stem gate valve. The valve stem is the operating part of the gate valve, and its function is to transmit the opening and closing force to the opening and closing parts.
1. The trapezoidal thread of the stem of the rising stem gate valve is placed outside the valve body and located on the upper part of the valve stem. By rotating the stem nut, the valve stem drives the gate plate to rise and fall synchronously to realize the opening and closing of the valve, so it is easy to identify the valve. Open and close state to avoid misoperation. Since the stem nut is outside the body cavity, it is conducive to lubrication, and the opening and closing state is intuitive and obvious, so it is widely used. However, in harsh environments, the exposed threads of the valve stem are susceptible to damage and corrosion, even affecting operation. Its disadvantage is that the height of the valve after opening is large, and a stroke is usually added to the original height of the valve, which requires a lot of operating space.
2. Dark stem gate valve is also called rotating stem gate valve (also called dark stem wedge gate valve). The stem nut is placed inside the valve body and is in direct contact with the medium. It is often fixed on the gate. Through the rotation of the valve stem, the valve stem nut drives the gate to move up and down to complete the opening and closing. Usually there is a trapezoidal thread at the bottom end of the valve stem. Through the thread at the bottom end of the valve and the guide groove on the valve disc, the rotary motion is changed into linear motion, that is, the operating torque is turned into operating thrust. Since the trapezoidal thread used for transmission is located inside the valve body, it is easily corroded by the medium and cannot be lubricated. The opening degree cannot be directly observed, and an indicating device is required. However, its valve stem does not move up and down, and requires a small operating space, so it is suitable for occasions with limited locations and dense pipelines.

gate valve (3)

Classified by structure:
According to the structure type, it can be divided into two types: wedge gate valve and parallel gate valve. That is, a wedge-type gate valve is called a wedge gate valve, and a parallel gate valve is a flat gate valve.
1. The flat gate valve means that the sealing surface is parallel to the vertical centerline, so the sealing surface of the valve body and the gate plate are also parallel to each other. The most common type of this kind of gate valve is the double gate type. In order to make the valve body and the two sealing surfaces of the gate closely contact when closed, a double-sided thrust wedge is often used between the two gates. Most of them are used on low-pressure pipelines such as small pipelines. Parallel gate valves using single gates are also rare but rare.
2. Wedge gate valve means that the sealing surface is at a certain angle to the vertical centerline, that is, the two sealing surfaces are wedge-shaped gate valves. The wedge gate valve has single and double gate plates. The advantage of the double gate type is that the accuracy of the sealing and the angle is lower, the temperature change is not easy to make the gate wedged, and the sealing surface wear can be compensated with gaskets. The disadvantage is that the structure is complex, and it is easy to stick in dry media, and the main reason is that the upper and lower baffles are easy to fall off after years of corrosion.
Classification by other methods:
According to different standards: national standard gate valve, American standard gate valve, German standard gate valve, Japanese standard gate valve
According to the connection method: flanged gate valve, welded gate valve, threaded gate valve (divided into internal thread and external thread)
According to pressure level: high pressure gate valve, low (medium) pressure gate valve According to driving mode: electric gate valve, pneumatic gate valve, manual gate valve
Classified by material: stainless steel gate valve, forged steel gate valve, cast steel gate valve, carbon steel gate valve, cast iron gate valve, copper gate valve (also divided into bronze gate valve, brass gate valve), ceramic gate valve, plastic gate 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

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

July 8, 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

rising stem gate valve-OS&Y

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.
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;

non-rising-stem-gate-valve-IS&Y

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;
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.

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 of electric gate valve

June 30, 2021

Principle of electric gate valve, Working principle of electric gate valve
Principle of electric gate valve:
Electric gate valve, as the name suggests, is to control the gate valve with an electric actuator, which is mainly

electric stainless steel gate valve

divided into an upper part and a lower part. The upper part is an electric actuator, and the lower part is a gate valve. Connect the actuator and the gate valve, and the electric actuator controls the opening and closing of the gate valve to work to achieve the on-off of the pipeline medium. Gate valves are generally suitable for on-off occasions and are normally open and normally closed valves. If you need to adjust the working conditions, generally choose electric control valve, electric ball valve, electric butterfly valve, electric shut-off valve, etc.
Working principle of electric gate valve:
The electric gate valve is powered by electric energy to turn on the electric actuator to drive the valve, and the valve stem is connected to drive the valve plate to move up and down or open and close, so that the valve can control the switch of the pipeline medium. It can be remotely controlled when it is added into the control box and other accessories, which is convenient and trouble-free.
Classification of electric gate valve actuators:
There are two common types of rotary electric actuators and linear electric actuators. Angular-stroke electric actuator: the angular-stroke electric actuator is used in conjunction with the angular-stroke valve to realize the internal rotation of the valve within 90 degrees to control the flow of the pipeline.
Straight-stroke electric actuator: a straight-stroke electric actuator is used in conjunction with a straight-stroke valve to realize the up and down movement of the valve plate to control the on-off of the pipeline fluid. It is usually used in conjunction with equipment with a higher degree of automation.

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 of Pneumatic Gate Valve

June 29, 2021

Brief introduction of pneumatic gate valve:
The pneumatic gate valve is equipped with a pneumatic actuator, which is driven by compressed air to control the gate valve. The valve core is composed of a wedge-shaped structure and a parallel structure, which is suitable for the emergency cut-off and discharge of gas and liquid pipelines.

pneumatic gate valve (3)

Working principle of pneumatic gate valve:
When using the air source to operate the gate valve, the small handle of the manual device must be turned to the pneumatic position to open and close the nut and the screw rod. When the compressed air enters from the upper pipeline of the cylinder, the piston and the piston rod in the cylinder are pushed straight When the compressed air enters from the lower pipe, the gas pushes the piston and piston rod in the cylinder to move upwards, and at the same time drives the valve stem to move upwards to open the valve. When there is no air source, the screw rod and the opening and closing nut can be used to open and close the valve. First, the upper and lower intake pipes of the cylinder are in the exhaust state, and the small handle of the manual part is in the manual position, so that the opening and closing nut and the screw are in the manual position. In the normal meshing state, turn the large handwheel at the manual part at this time. When the handwheel is turned clockwise, the valve is closed, and when the handwheel is turned counterclockwise, the valve is opened. When the air source is introduced from the upper air inlet, the valve stem drives the valve plate to move downward, and the valve is closed.
When the air source is introduced from the lower air inlet, the valve stem drives the valve plate to move upward, and the valve opens.
Pneumatic gate valve parameters:
Actuator: cylinder piston structure;
Optional accessories: manual device, filter, solenoid valve, echo device, control box;
Main material: ductile iron, cast steel, stainless steel; Caliber: DN50-500;
Pressure: PN1.6-6.4mpa;
Temperature: Q-29～350℃, C-29～450℃, P-30～540℃;
Medium range: water, steam, petroleum, gas, fluid, medium containing hard particles and impurities.

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, API6

The structure and characteristics of bellows gate valve

June 24, 2021

The structure and characteristics of bellows gate valve
The valve stem of the bellows gate valve adopts a double sealing structure of bellows and packing to ensure a leak-free seal at the valve stem. It is used in power stations, natural gas, ammonia, vacuum, refrigeration systems, hot oil, and hot water systems. It is especially suitable for flammable, Pipelines for explosive, toxic and precious media.

rising stem gate valve-OS&Y (3)

Bellows gate valve structure:
The bellows, bonnet and stem of the bellows gate valve are welded into one body without seams, so there is no leakage. The action of the valve stem is caused by the deformation of the compressed bellows, not by relative movement. Ordinary gate valves are sealed with packing, the valve stem and packing will slide, and it is easy to leak (spool) at low temperatures. Bellows gate valves do not have this problem.
Structure diagram of bellows gate valve
Bellows gate valves use stainless steel hermetic bellows that can be stretched and compressed instead of packing seals. They are generally used for the transmission of more permeable media, such as valves on hydrogen systems. As long as the bellows are not damaged, there is generally no leakage; while general gate valves Packing is used for sealing, which is prone to leakage.
Features of bellows gate valve:
1: The corrugated gate valve is double-sealed, bellows (stainless steel) + packing, and has better safety performance, so it is often used in systems such as toxic media, flammable and explosive media, high-temperature steam, and hot oil.
2: The switching torque is small, the switching is relatively easy, there is no flow resistance loss, the service life is long, and the appearance is beautiful. Related knowledge: Working principle of gate valves Types and classifications of gate 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
related news /knowledge: Comparison of bellows globe valve and ordinary globe valve; Fasteners, fillers and gasket materials of valves;

The difference between internally and externally threaded valves

June 1, 2021

Threaded valve (also called internal threaded valve) generally refers to a valve with internal or external thread on the valve body. It is mainly divided into internal threaded valve and external threaded valve. Corresponding to the pipeline. Usually threaded valves can only be manufactured with small diameters and are used for normal pressure or low pressure projects. If they are not available for high pressure work, they need to be used with welded link valves or flanged valves.

internally threaded valve and externally threaded valve

Common threaded valves are: threaded gate valve, threaded ball valve, threaded globe valve, threaded check valve.
The difference between internal threaded valve and external threaded valve:
From the point of use: Due to price and working flow requirements, most of the valves on the market use internal threaded valves. From the channel: Taking into account the thread connection, the passage of the external thread of the same caliber is smaller than the internal thread, the flow rate is faster, and the flow rate is small.
From the appearance: Most of the internal threads are pipe threads, the external threads are mostly taper threads, and the bite-type external threads are pipe threads.
In terms of pressure resistance: The wall of the valve with external thread of the same material is usually thicker than that of the internal thread (the smaller the passage, the thicker the wall), and the pressure resistance is greater. This is the reason why valves with high pressure ratings are all external threads. To
Sealing form of threaded valve:
1. Direct sealing: internal and external threads directly play a sealing role. In order to ensure that the joints are not leaking, they are often filled with lead oil, thread hemp and PTFE raw material tape; among them, PTFE raw material tape is widely used every day; this material has good corrosion resistance and extremely sealing effect. Good, it is convenient to use and store. When disassembling, it can be completely removed, because it is a non-sticky film, which is much better than lead oil and hemp.
2. Indirect sealing: the tightening force of the thread is transmitted to the gasket between the two planes, so that the gasket plays a sealing role.
Thread standard of threaded valve:
1. International standards ISO228/1, DIN259, are internal and external parallel threads, code G or PF (BSP.F);
2. German standard ISO7/1, DIN2999, BS21, taper external thread, parallel internal thread;
3. British standard ISO7/1, BS21, internal and external tapered thread, code PT or BSP.Tr or Rc;
4. American standard ANSIB21, internal and external tapered thread, code name NPT.

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 structure and connection of the American standard valve

November 25, 2020

American standard valves mainly have API and ASME standards. ASTM and ASTM are material standards; valves designed, manufactured, produced and tested according to American standards are called American standard valves.
The American standard valve is a control component in the fluid conveying system. It has the functions of cut-off, regulation, diversion, prevention of reverse flow, voltage stabilization, diversion or overflow and pressure relief; the valve used in the fluid control system is cut off from the simplest American standard. There are many types and specifications of American standard valves used in extremely complex automatic control systems. Valves can be used to control the flow of various types of fluids such as air, water, steam, various corrosive media, mud, oil, liquid metal and radioactive media. Valve types: gate valve, knife gate valve, check valve, butterfly valve and others.

The structure types:

code	structure type	explaination	standard	face to face
C	BB-BG-OS&Y	bolted bonnet, bolted gland, outside screw & yoke	API602/API602M	ASME B16.10
D	BB-BG-OS&Y	bolted bonnet, bolted gland, outside screw & yoke	API603/API603M	ASME B16.10
E	BB-BG-OS&Y-N	bolted bonnet, bolted gland, outside screw & yoke-needle type	API602M	ASME B16.10
G	BC-PISTON-LIFT	(BOLTED BONNE,PISTON-LIFT)	API602M	ASME B16.10
H	BC-PISTON-LIFT	(BOLTED BONNE,PISTON-LIFT) outside screw & yoke	API603M	ASME B16.10
B	BB-BG-OS&Y-W	BOLTED BONNET,BOLTED GLAND,OS&Y ,BELLOWS SEAL TYPE)	API600M	ASME B16.10
L	BB-BG-OS&Y-L	BOLTED BONNET,BOLTEDGLAND ,OS&Y ,CRYOGENIC SERVICE SRRUCTURE	ASME B16.34	ASME B16.10
1	BC-SWING	(BOLTED BONNET,SWING)	API600M	ASME B16.10
2	PS-PISTON-LIFT	(PRESSURE SEAL BONNET,PISTON-LIFT)	API600M	ASME B16.10
3	WAFER TYPE	(WAFER CHECK VALVE)	API594	API594
4	TILTING-DISC	（TILTING-DISC TYPE CHECK VALVE）	API600M	ASME B16.10
5	BB-BG-OS&Y-F	(BOLTED BONNET,BOLTED GLAND,OS&Y,WITH SPECCIAL PACKING)	API600/API600M	ASME B16.10
6	BB-BG-OS&Y	(BOLTED BONNET,BOLTED GLAND,OS&Y)	API600/API600M	ASME B16.10
7	BB-BG-OS&Y-H	(BOLTED BONNET,BOLTED GLAND,OS&Y,WITH BLOMING HOLE)	API600/API600M	ASME B16.10
8	PS-BG-OS&Y	(PRESSURE SEAL BONNET,BOLTED GLAND,OS&Y)	API600/API600M	ASME B16.10
9	PS-COVER SWING	(PRESSURE SEAL BONNET, SWING)	API600/API600M	ASME B16.10
M	BB-BG-M-SEAL	PRESSURE SEAL BONNET,BOLTED GLAND,moving sealing	API600M	ASME 16.10

connection types:

code	connection type	explaination
S	SW	SOCKET WELDED
T	NPT	60° Taper pipe thread/NATIONAL TAPER PIPE THREAD
G	Rc	55° TAPER PIPE THREAD
R	RF	RAISED FACE
J	RJ	RING JOINT
W	BW	BUTT－WELDED
P	PIPE	EACH ENDWITH A 150mm SHORT PIPE
F	MF(F)	MALE-FEMALE FACE(FEMALE)
A	RF-NPT	one side RF, one side NPT

Tianjin Tanghai Valve Manufacturing Co., Ltd. is one of the largest butterfly valve manufacturers in China. It was founded in 2006. Its predecessor was Tanghai Valve Manufacturing Factory. Now we have our own independent R & D, manufacturing, assembly and warehousing workshops; we have professional pre-sale and after-sale technical support and perfect services.

Our products use advanced manufacturing technology, and strictly conform to API, DIN, BS, EN, ISO, GB and other international standards. The main products are butterfly valves, gate valves, check valves, globe valves, valve parts (Valve body, Valve disc, Valve shaft, Valve seat…), etc. Our products are widely used in various fields such as marine industry, shipbuilding, petrochemical, metallurgy, water treatment, fire fighting, water supply and drainage, etc. The company has won unanimous recognition and praise from customers with high quality and good reputation.

Tianjin Tanghai Valve Manufacturing Co., Ltd. is one of the largest butterfly valve manufacturers in China, main products are butterfly valves, check valves, gate valve and globe valves. Key words: butterfly valve, lug type butterfly valve, wafer type butterfly valve, U-type butterfly valve, double flange butterfly valve, gate valves, check valves, globe valves, valve parts (Valve body, Valve disc, Valve shaft, Valve seat…)

URL: http://www.tanghaivalve.com

Name: Harry Li

Email: harry@tanghaivalve.com

Wafer butterfly valve-PN20-WCB-ANSI-150 (4)

Wafer butterfly valve-PN20-WCB-ANSI-150 (2)

Wafer butterfly valve-PN20-WCB-ANSI-150 (6)

Wafer butterfly valve-PN20-WCB-ANSI-150 (1)

rising stem gate valve-OS&Y

The difference between carbon steel and cast steel

November 24, 2020

What is the difference between cast steel and carbon steel? First, steel is classified by chemical composition
(1) Carbon steel: a. Low carbon steel (C≤0.25%) b. Medium carbon steel (C≤0.25~0.60%) c. High carbon steel (C≤0.60%)
Steel is classified according to the forming method: (1) Forged steel (2) Cast steel (3) Hot rolled steel (4) Cold drawn steel. The so-called cast steel and carbon steel are just the names produced by the different classifications of steel.

What is the difference between forged steel valve and cast steel valve? Forging and casting are two different

flanges

processing techniques.
Casting: The molten liquid metal fills the cavity and cools. Pores are easy to produce in the middle of the workpiece.
Forging: It is mainly formed by extrusion at high temperature. Can refine the crystal grain in the part.
Forging: Use hammering and other methods to make a metal material in a plastic state into a workpiece with a certain shape and size, and change its physical properties.
Casting: The metal is heated and melted and poured into a sand mold or mold, and solidified into a utensil after cooling.
The difference in performance
During forging, the metal undergoes plastic deformation to refine grains.

What is the difference between a cast iron valve and a cast steel valve? The main difference between cast iron and cast steel valves is the carbon content, which directly affects the strength and plasticity of the steel. Carbon steel is also called carbon steel, an iron-carbon alloy with a carbon content of less than 2% WC. In addition to carbon, carbon steel generally contains a small amount of silicon, manganese, sulfur, and phosphorus. According to its purpose, carbon steel can be divided into three types: carbon structural steel, carbon tool steel and free-cutting structural steel. Carbon structural steel is divided into building structural steel and machine-manufactured structural steel. According to the carbon content, carbon steel can be divided into low-carbon steel (WC ≤ 0.25%) and medium-carbon steel (WC0.25%-0.6%) And high-carbon steel (WC>0.6%) According to phosphorus and sulfur content, carbon steel can be divided into ordinary carbon steel (higher phosphorus and sulfur), high-quality carbon steel (lower phosphorus and sulfur) and high-quality Steel (lower phosphorus and sulfur) Generally, the higher the carbon content of carbon steel, the higher the hardness and the higher the strength, but the lower the plasticity.
The full name of carbon steel is carbon structural steel. Cast steel valves are also carbon steel valves (there are also cast iron valves). They are just made by casting methods, while common steels are made by rolling. The ingredients are the same.

What is the difference between cast steel, cast iron and carbon steel in valve materials? Simply put, you first

lug type butterfly valve, ductile iron, center lined,

distinguish between iron and steel. Both steel and iron are alloys based on iron and carbon as the main additive element, collectively referred to as iron-carbon alloys.
The cast iron is smelted in an iron melting furnace to obtain cast iron (liquid), and the liquid cast iron is cast into a casting, which is called a cast iron.
What is the difference between cast steel and carbon steel. First, steel is classified by chemical composition
(1) Carbon steel: a. Low carbon steel (C≤0.25%); b. Medium carbon steel (C≤0.25~0.60%); c. High carbon steel (C≤0.60%).
Steel is classified according to the forming method: (For valves with different pressures, different materials are used.
Medium and low pressure valve, the valve body material is cast iron. For high-pressure valves, because of the large pressure, the valve body must be made of cast steel. Special valves may use various alloy materials and stainless steel.
It is said that carbon steel is only a kind of steel, and cast steel is a processing method of steel, not a concept.

What is the difference between carbon steel gate valve and cast steel gate valve. Many people think that carbon steel gate valves and cast steel gate valves are two kinds of materials.
1. The cast steel check valve and carbon steel check valve are check valves of the same material, both of which are made of WCB A216 carbon steel.
2. Cast steel check valve, because the valve body of WCB material is cast, so the name suggests, it is called cast steel check valve.
3. Carbon steel check valve, because the main material of WCB material is carbon steel, it is named carbon steel check valve.

The forging process of steel is different in processing form. Cast steel The steel used for pouring castings. A kind of casting alloy. Cast steel is divided into cast carbon steel, cast low alloy steel and cast special steel. Cast steel refers to a type of steel casting produced by casting methods. Cast steel is mainly used to manufacture some parts with complex shapes, difficult to forge or cutting and forming, but require high strength and plasticity. Forged steel: Forged steel refers to various forgings and forgings produced by forging methods. The quality of forged steel parts is higher than that of cast steel parts, can withstand large impact forces, and have plasticity, toughness and other mechanical properties.

What is the meaning of cast steel and carbon steel of the valve? What is the meaning of cast steel and carbon steel. Thank you. Carbon steel is represented by CS, but it is generally not mentioned in the case of cast steel. Detailed materials such as WCB, WCC, LCC, etc. will be stated.

The valve is a control component in the fluid conveying system. It has the functions of cut-off, regulation, diversion, prevention of reverse flow, stabilization, diversion or overflow and pressure relief. Valves used in fluid control systems, ranging from the simplest shut-off valve to the various valves used in extremely complex automatic control systems, have a wide variety and specifications.
Valves can be used to control air, water, steam, various corrosive media, mud, oil, liquid metal and radioactive media. >>Cast steel has less carbon content, good toughness, and higher pressure and temperature resistance than cast iron. Cast iron valves are not suitable for diesel, sea water and acid media. Cast iron valves are cheaper. Their materials are obviously different, and they are used in different environments! The cost is also different. In short, the price is analyzed in detail, and the properties of various materials are different. Temperature resistant. Cast steel valves can withstand high temperatures, but cast iron valves cannot be used with water.

Resilient seated socket end gate valve

November 18, 2020

GATE VALVE-resilient seated SOCKET END
Standard: EN1074; EN1171

Socket ended resilient seated wedge gate valve-ductile iron (1)

CAST IRON / DUCTILE IRON GATE VALVE SOCKET END
NON RISING STEM
Pressure: PN10 / PN16
Connection ends: Socked ends, for PVC pipes, uPVC pipes
FACE TO FACE: ACCORDING TO BS, DIN, ANSI, AWWA, SABS STANDARD ETC.
BODY:CAST IRON/DUCTILE IRON
BONNET:CAST IRON/DUCTILE IRON
WEDGE:CAST IRON/DUCTILE IRON, fully vulcanized with EPDM rubber
STEM: SS/BRASS
Coating: fusion bonded expoxy coating

The opening and closing part of the socket gate valve is a gate. The movement direction of the gate is perpendicular to the direction of the fluid. The gate valve can only be fully opened and fully closed, and cannot be adjusted or throttled. The gate has two sealing surfaces. The two sealing surfaces of the most commonly used mode gate valve form a wedge. The wedge angle varies with valve parameters, usually 50, and 2°52′ when the medium temperature is not high. The gate of the wedge gate valve can be made into a whole, called a rigid gate; it can also be made into a gate that can produce slight deformation to improve its manufacturability and compensate for the deviation of the sealing surface angle during the processing. The plate is called an elastic gate.

Socket gate valve can be divided into wedge gate valve and parallel gate valve according to the sealing surface configuration. The wedge gate valve can be divided into: single gate, double gate and elastic gate; parallel gate valve can be divided into It is single gate type and double gate type. According to the thread position of the valve stem, it can be divided into two types: rising stem gate valve and non-rising stem gate valve.

When the socket 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 against the valve seat on the other side to ensure the sealing of the sealing surface, which is self-sealing. Most gate valves use 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.

The gate of the socket gate valve moves linearly with the valve stem, which is called rising stem gate valve (also called rising stem gate valve). 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 into operating thrust.

When the valve is opened, when the lifting 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 a mark, that is, the position where it cannot be opened, as its fully open position. In order to take into account the locking phenomenon of the temperature change, it is usually at the top position of the opening, and then rewind 1/2-1 turn as the position of the fully open valve. Therefore, the fully open position of the valve is determined by the position of the gate (that is, the stroke).

Socket ended resilient seated wedge gate valve-ductile iron (2)

In some gate valves, the stem nut is set on the gate, and the rotation of the handwheel drives the rotation of the valve stem to lift the gate. This kind of valve is called a rotating stem gate valve or a dark stem gate valve.

advantage:
The fluid resistance is small, and the sealing surface is less brushed and corroded by the medium.
It is easier to open and close.
The flow direction of the medium is not restricted, does not disturb the flow, and does not reduce the pressure.
The shape is simple, the length of the structure is short, the manufacturing process is good, and the scope of application is wide.

Disadvantages:
It is easy to cause erosion and scratches between the sealing surfaces, which makes maintenance difficult.
The overall size is large, opening requires a certain amount of space, and the opening and closing time is long.
The structure is more complicated.

The types of socket gate valves can be divided into wedge gate valves and parallel gate valves according to the sealing surface configuration. Wedge gate valves can be divided into: single gate type, double gate type and elastic gate type; parallel gate type Gate valves can be divided into single gate type and double gate type. Divided according to the thread position of the valve stem, it can be divided into two types: open stem gate valve and dark stem gate valve.

Matters needing attention in installation and maintenance
Handwheels, handles and transmission mechanisms are not allowed to be used for lifting, and collisions are strictly prohibited.
The double gate valve should be installed vertically (that is, the valve stem is in the vertical position and the handwheel is at the top).
The gate valve with bypass valve should be opened before opening (to balance the pressure difference between inlet and outlet and reduce the opening force).
The gate valve with transmission mechanism should be installed according to the product manual.
If the valve is frequently opened and closed, lubricate at least once a month.

Structural features:
The general gate valves used on the market for a long time generally have water leakage or rust. The company introduces the elastic seat seal gate valve produced by European high-tech rubber and valve manufacturing technology, which overcomes the defects of poor sealing and rust of general gate valves. The sealing gate valve uses the compensation effect of the elastic gate plate to produce a small amount of elastic deformation to achieve a good sealing effect. The valve has the obvious advantages of light switch, reliable sealing, good elastic memory and service life. It can be widely used as a regulating and intercepting device on the pipelines of tap water, sewage, construction, petroleum, chemical industry, food, medicine, textile, electric power, shipbuilding, metallurgy, energy system, etc.

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