butterfly valve Archives

Vulcanized vs soft seated/back-up butterfly valve

June 17, 2021

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

Fluorine lined butterfly valve-PTFE-WAFER (8)

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

wafer type butterfly valve (6)

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

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

The working principle of butterfly valve (picture)

June 15, 2021

Working principle of butterfly valve:
The butterfly valve is a valve that opens and closes according to the rotation of the valve stem, while driving the disc plate to rotate. In the cylindrical channel of the butterfly valve body, the disc-shaped butterfly plate rotates around the axis, mainly by rotating the disc plate 90° for flow control. When the disc reaches 90°, the valve is in a fully open state, and the angle of the disc can be changed to adjust the medium flow. It is generally installed in the

U-type-flange-butterfly-valve-2

diameter direction of the pipe. The butterfly valve and the valve stem have no locking ability. In order to effectively adjust the flow, a worm gear reducer is required. The butterfly valve with a worm gear reducer not only makes the butterfly valve self-locking, but also changes the operating performance of the butterfly valve and adjusts the medium flow more accurately. .
Features of butterfly valve:
(1) Simple structure and small size. Due to its compact structure, short structure length, small size and light weight, it is suitable for large diameters.
(2) The fluid resistance is small. When fully opened, the effective flow area of the valve seat channel is large, so the fluid resistance is small.
(3) The opening and closing is convenient and rapid, the adjustment performance is good, and the butterfly plate rotates 90. Both can complete the opening and closing. The flow can be controlled in stages by changing the rotation angle of the butterfly plate.

(4) The opening and closing moment is small, because the discs on both sides of the rotating shaft are basically the same under the action of the medium, and the direction of the torque is opposite, so the opening and closing is labor-saving.
(5) The low-pressure sealing performance is good, and the sealing surface material is generally rubber or plastic, so the sealing performance is good. Limited by the material of the sealing ring, the operating pressure and operating temperature range of the butterfly valve is relatively small. However, the working pressure and working temperature range of the hard seal butterfly valve have been greatly improved.

butterfly valve working diagram-3D GIF animated presentation

1. The butterfly valve has a small flow resistance when it is fully opened. When the opening is between about 15° and 70°, it can carry out sensitive flow control. Therefore, the application of butterfly valves is very common in the field of large-diameter adjustment. Since the movement of the butterfly plate of the butterfly valve is wiping, most butterfly valves can be used for media with suspended solid particles. Depending on the strength of the seal, it can also be used for powder and granular media.
2. The butterfly valve is suitable for flow adjustment. Because the pressure loss of the butterfly valve in the pipe is relatively large, about three times that of the gate valve, when selecting the butterfly valve, the influence of the pressure loss of the piping system should be fully considered, and the strength of the butterfly plate to withstand the pressure of the pipeline medium when it is closed should also be considered. . In addition, it is necessary to consider the limitation of the working temperature that the elastic valve seat material can withstand at high temperatures. To
3. The structural length and overall height of the butterfly valve are small, the opening and closing speed is faster, and it has good fluid control characteristics. The structure principle of butterfly valve is most suitable for making large-diameter valves. When a butterfly valve is required to control flow, the most important thing is to correctly select the specification and type of the butterfly valve so that it can work properly and effectively.
Related knowledge: Principles of butterfly valve structure
Related products: Electric switching butterfly valve Electric regulating butterfly valve

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

Representation method of butterfly valve model

June 11, 2021

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

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

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

Butterfly valve model representation method:
Additional code of butterfly valve: BD: thermal insulation butterfly valve, SD: telescopic butterfly valve, TLD: desulfurization butterfly valve, DH: check butterfly valve, DKS: fast butterfly valve, FDBD: square louver butterfly valve;
The code of the butterfly valve: D: represents the butterfly valve;
Transmission form code: manual (omitted), 3: means turbine drive, 6: means pneumatic drive, 7: means hydraulic, 9: means electric;
Connection code code: 4: flange type, 6: welding, 7: pair clamp type;

Structure code code: 1: means centerline type, 2: means double eccentricity, 3: means triple eccentricity, 4: means variable eccentricity, 5: means single eccentricity;
Sealing material code: H: stainless steel, X: rubber, F: polytetrafluoroethylene, FX: composite rubber, M: Monel alloy, Y: cemented carbide, W: valve body directly processed;
Pressure grade code: 10=PN1.0Mpa, 16=PN1.6, 25=PN2.5, 40=PN4.0, PN is the code of domestic pressure, MPA is the unit of pressure, one kilogram is equal to 0.1Mpa; Class150LB=1.6 mpa, 300LB=2.5-4.0mpa, Class is the American standard code, LB is the American standard pound unit.
Shell material code: C: cast steel, P: stainless steel 304, R: stainless steel 316, AL: special alloy steel, Z: cast iron, Q: ductile iron, N: nylon.
The above are common codes related to butterfly valves. For products that need to be customized due to special working conditions, they can be selected according to the design plan.
Examples of butterfly valve model compilation:
D943H-16C electric triple eccentric butterfly valve
D: Represents butterfly valve;
9: Indicates that the transmission mode is electric;
4: The connection method is flange connection;
3: The structure is triple eccentric;
H: The sealing material is stainless steel;
16: Indicates that the nominal pressure is 1.6MPa;
C: Indicates that the valve body material is cast steel.
Related valve model: Valve model Globe valve model Check valve model Gate valve model Regulating valve model Ball valve model

See complete coding method on: Valve model establishment and meaning

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

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

June 10, 2021

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

Double flange butterfly valve (16)

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

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

Wafer butterfly valve installation instructions and steps

June 10, 2021

Wafer butterfly valve is one of the most common types of valves in industrial pipelines. The wafer butterfly valve itself has a relatively small structure. You only need to put the butterfly valve in the middle of the flanges at both ends of the pipeline, and use stud bolts to pass through the pipeline flange and the The clip-on butterfly valve is locked to control the fluid medium in the pipeline. Wafer butterfly valve is especially suitable for places with narrow space or short distance between pipelines. When the butterfly valve is in the fully open position, the thickness of the butterfly plate is the only resistance when the medium flows through the valve body. Therefore, the pressure drop generated by the valve is very high. Small, so it has better flow control characteristics.

wafer type butterfly valve, with handle (13)

1. Instructions before installation of wafer butterfly valve:
1. Before installation and operation, use air spray to remove foreign objects on the piping, and clean the inner surface of the piping with clean water.
2. Carefully check whether the valve usage is consistent with its performance specifications; (temperature, pressure)
3. Check the valve channel and sealing surface for debris, and remove it in time;
4. The valve must be installed in time after unpacking, please do not loosen any fastening screws or nuts on the valve at will;
5. Wafer butterfly valves must use special butterfly valve flanges.
6. The electric butterfly valve can be installed on the pipeline at any angle. For the convenience of maintenance, it is recommended not to install it upside down.
7. When installing the butterfly valve flange, it must be ensured that the flange surface and the sealing rubber are aligned, the screws are evenly tightened, and the sealing surface must fit completely; if the screw tightening force is uneven, the rubber bumps will block the butterfly plate, or the top Staying on the butterfly plate causes leakage at the valve stem. To
2. The installation steps of the wafer butterfly valve: The correct installation of the wafer butterfly valve is related to the sealing degree of the butterfly valve, and whether it will leak or not, including the safety in working conditions. The user should understand the installation process.

wafer & lug type butterfly valve (7)

1. As shown, place the valve between the two pre-installed flanges, paying attention to the alignment of the bolt holes.
2. Gently insert four pairs of bolts and nuts into the flange holes, and tighten the nuts slightly to correct the flatness of the flange surface;
3. Fix the flange to the pipeline by spot welding;
4. Remove the valve;
5. Fully weld and fix the flange on the pipeline;
6. Install the valve after the welding port has cooled down. Ensure that the valve has enough space in the flange to prevent the valve from being damaged, and ensure that the valve plate has a certain degree of opening;
7. Correct the valve position and tighten the four pairs of bolts (be careful not to over tighten)
8. Open the valve to ensure that the valve plate can be opened and closed freely, and then slightly open the valve plate;
9. Tighten all nuts in cross balance;
10. Reconfirm that the valve can open and close freely. Note: Confirm that the valve plate does not touch the pipeline.
The installation of the wafer butterfly valve must be laid flat before installation, remember not to bump it at will, after it is drawn to the installation length during installation, in the design of the on-site pipeline, it is not possible without special permission Disassemble the wafer butterfly valve at will, this is what we need to know before installation. At the same time, everyone should know that the wafer butterfly valve can be installed in any position, but after the wafer butterfly valve is installed, the butterfly valve needs to be laid along the line, and a bracket is made for the wafer butterfly valve. Once the bracket is made, it will be used At that time, it is strictly forbidden to remove the bracket.
Related products: Electric wafer butterfly valve Pneumatic wafer butterfly valve

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

Cryogenic valve principle |standard |illustration |selection

June 3, 2021

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

triple offset valve parts-after-cryogenic process

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

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

Selection of ultra-low temperature valve:

cryogenic triple offset butterfly valve 1

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

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

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

Ultra-low temperature valve design standards:

1. Design: API6D, JB/T7749

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

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

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

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

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

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

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

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

7 types of flange sealing surface: FF, RF, M, FM, T, G, RTJ

April 20, 2021

Flanged butterfly valve has a flange on the valve, and bolts are used to connect the flanges at both ends of the valve to the pipe flange. Do you know all the 7 types of flange sealing surfaces? FF, RF, MF, M, T, G, RTJ
The flange sealing surface basically has:

Full plane: FF
Raised face: RF
Concave/female: FM
Convex/Male: M
Tenon: T
Groove surface: G
Ring connection surface RTJ (RJ) types, according to the different working conditions, medium, pressure, specifications, temperature, etc., so the selected types are not the same. Let’s get to know the types of these flange sealing surfaces together!
FF-full plane:
Flat Face Full Face type sealing surface is completely flat, suitable for occasions where the pressure is not high and the medium is non-toxic.

flange FF

RF-raised face:
The Raised Face type of sealing surface is the most widely used among several types, and the most commonly used one. The international standards, European system and domestic standards are all fixed heights, but in the American standard flange, it should be noted that the height of high pressure will increase the sealing surface. There are also many types of gaskets used. Gaskets suitable for raised face sealing surface flanges include various non-metallic flat gaskets, coated gaskets; metal-wrapped gaskets; spiral wound gaskets (including outer ring or inner and outer ring).

flange RF

Convex/Male: M
Concave /female: FM
The two types of sealing surfaces, Male Face and Female Face, are a pair, one female and one male. They must be used together. They are easy to align and prevent the gasket from being extruded. Suitable for occasions with higher pressure.
The suitable sealing gaskets for the concave-convex sealing surface include: various non-metallic flat gaskets and coated gaskets; metal-clad gaskets; basic type or winding stopper with inner ring, etc.
T-tenon
G-groove surface
Tongue Face and Groove Face are similar to the concave-convex surface. They are also a male and female matched sealing surface type, and they are also used in pairs. The gasket is located in the annular groove and is restricted by the metal walls on both sides. It can prevent the gasket from being compressed and deformed and squeezed into the pipeline. Since the gasket is not in direct contact with the fluid medium in the pipe, it is less eroded or corroded by the fluid medium, so it can be used for high pressure, flammable, explosive, and toxic mediums that require strict sealing. This kind of sealing surface gasket has good installation and neutrality, but it is difficult to process the sealing surface. It is easy to damage the sealing surface when replacing the gasket, and the flange must be separated in the axial direction during installation and disassembly. Therefore, consideration should be given to the pipeline design. It is possible to separate the flange in the axial direction.
Suitable gaskets for the sealing surface of the tongue and groove surface include: various metal and non-metal flat gaskets, metal-clad gaskets and basic spiral wound gaskets.

flange TG-

RTJ(RJ)-Ring connection surface
The flange of the Ring Joint Face seal is also a narrow-face flange, and an annular trapezoidal groove is opened on the flange surface as the flange sealing surface, which is the same as the tongue-and-groove flange. The flange must be separated in the axial direction during installation and disassembly. Therefore, the possibility of separating the flange in the axial direction should be considered in the pipeline design.
The sealing surface is specially designed to cooperate with solid metal gaskets processed into octagonal or elliptical shapes from metal materials to achieve a sealed connection. Since the metal ring gasket can be based on the inherent characteristics of various metals, the sealing performance of this sealing surface is good, and the installation requirements are not too strict. It is suitable for high temperature and high pressure working conditions, but the processing accuracy of the sealing surface is relatively high. (According to the Pipe Fittings, Pumps and Valves Alliance)

flange-RTJ-RJ-

flange-RTJ-RJ-02

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.

Accuracy requirements of Equipment installation

October 23, 2020

1. For static equipment
The vertical deviation of vertical equipment should not be greater than L/1000 and not greater than 10mm. Unless the drawings have special requirements.

lug type butterfly valve, ductile iron, center lined,

The horizontal deviation of horizontal equipment should not be greater than L/1000 in the axial direction and 2D/1000 in the radial direction.

2. For moving equipment
When the pump is aligned, the selection of the installation datum and the allowable deviation of the level must meet the requirements of the “special specification” or the pump technical file. Generally, the allowable deviation of horizontal horizontality is 0.10mm/m, and the allowable deviation of vertical horizontality of the installation datum part is 0.05mm/m. The leveling and alignment values must not be adjusted by loosening the anchor bolts.
1. The pump that is disassembled and installed is based on the processing surface of the pump body, and the allowable deviation of the horizontality of the pump in the vertical and horizontal directions is 0.05mm/m.
2. The integrally installed pump should be leveled based on the inlet and outlet flange surface or other horizontal processing datum plane. The allowable deviation of horizontality is 0.05mm/m in the longitudinal direction and 0.10mm/m in the transverse direction.
3. When the driving shaft and the driven shaft are connected by a coupling, the centering deviation of the two shafts and the gap between the end faces of the two shafts should be:
Centering deviation: the radial displacement is not more than 0.03mm.
The axial tilt should not be greater than 0.05/1000.
The end face gap is 1.00~3.5mm.

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