manufacturer Archives

Raised face flange and concave and convex face flange

September 14, 2020

Flange is used for the connection between two devices. The abbreviation refers to the form of the sealing surface. There are holes on it. The two flanges are connected by bolts. It is generally used for The mutual connection between

flanges

the shaft and the shaft is also used for the connection between the pipe ends; it is a detachable connection of a set of combined sealing structures that are connected by flanges, gaskets and bolts. The thickness of flanges with different pressures is different, and their use forms are also different.

Commonly used butterfly valves include wafer butterfly valves and flange butterfly valves. Wafer type butterfly valve uses double-head bolts to connect the valve between two pipe flanges. Flange type butterfly valve has flanges on the valve, and the two ends of the valve are flanged to the pipe flanges with bolts.
For the most common raised face flanges and concave and convex face flanges, in the flange connection, the raised face flange needs to be matched with the concave face flange, commonly known as one male and one female, and the raised face flange should be matched with the raised face flange. Generally speaking, raised face flanges should also be a kind of flat flanges, code-named RF, and the RF face can only be linked with the RF face. The code name of the raised face flange is M, and the M face flange needs to be connected with the FM face. One is female FM (Female Male), and the other is male M (Male). The pressure on the M/FM side is better than that on the RF side. Raised face flanges and raised face flanges are used in pairs, and the code name is RF. The comparison chart of the two is as follows:

RF, MFM flanges

The angle between the sealing surface of the raised face flange and the flange bolt connection surface is 45°, and the sealing surface of the concave and convex flange and the flange bolt connection surface are 90° angle, that is, the two sides are perpendicular .

Raised face flanges are more commonly used in the market, and generally there is no problem below 2.5MPa. Concave-convex flanges are more expensive and have better sealing effect, so the applicable pressure level is higher. When designing, it is more troublesome. For example, when you mention the equipment condition diagram, you must indicate what type of method it is. Lan, and then when the statistics take over the material, it is another matching flange.

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

Comparison table of valve diameter and medium flow rate

September 14, 2020

It is well known that the flow rate and flow rate of the valve mainly depend on the diameter of the valve, and also

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

related to the resistance of the valve structure to the medium. At the same time, it has a certain internal connection with various factors such as the valve pressure, temperature and medium concentration. The flow channel area of the valve has a direct relationship with the flow rate and flow rate, and the flow rate and flow rate are two mutually dependent quantities. When the flow rate is constant, the flow rate is large, the flow channel area can be smaller; the flow rate is small, the flow channel area can be larger. On the contrary, the flow channel area is large, its flow velocity is small; the flow channel area is small, its flow velocity is large.
1. The flow rate of the medium is large, and the valve diameter can be smaller, but the resistance loss is large and the valve is easily damaged. If the flow velocity is large, it will have electrostatic effect on flammable and explosive media, causing danger; the flow velocity is too small, the efficiency is low and it is not economical. For the medium with high viscosity and explosive, the flow rate should be smaller. The flow rate of oil and liquid with high viscosity is selected according to the viscosity, generally 0.1～2m/s.
2. In general, the flow rate is known, and the flow rate can be determined by experience. The nominal diameter of the valve can be calculated through the flow rate and flow rate.
3. The valve diameter is the same, its structure type is different, and the fluid resistance is also different. Under the same conditions, the larger the resistance coefficient of the valve, the more the flow rate and flow rate of the fluid through the valve will drop; the smaller the valve resistance coefficient, the less the flow rate and flow rate of the fluid through the valve will drop.
The common flow rates of various media are shown in the following table:

liquid type	use condition	speed m/s
satuated vapor	DN>200	30-40
	DN=200-100	25-35
	DN<100	15-30
superheated steam	DN>200	40-60
	DN=200-100	30-50
	DN<100	20-40
low pressure steam	P<1.0 (absolute pressure)	15-20
midium pressure steam	P=1.0-4.0 (absolute pressure)	20-40
high pressure steam	P=4.0-12.0 (absolute pressure)	40-60
compressed air	vaccum	5-10
	P≤0.3 (instrument pressure)	8-12
	P=0.3-0.6 (instrument pressure)	10-20
	P=0.6-1.0 (instrument pressure)	10-15
	P=1.0-2.- (instrument pressure)	8-12
	P=2.0-3.0 (instrument pressure)	3-6
	P=3.0-30.0 (instrument pressure)	0.5-3
Oxygen	P=0-0.05 (instrument pressure)	5-10
	P=0.05-0.6 (instrument pressure)	7-8
	P=0.6-1.0 (instrument pressure)	4-6
	P=1.0-2.0 (instrument pressure)	4-5
	P=2.0-3.0 (instrument pressure)	3-4
gas		2.5-15
semi-water gas	P=0.1-0.15 (instrument pressure)	10-15
natural gas		30
Nitrogen	P=5.0-10.0 (absolute pressure)	15-25
Ammonia	vaccum	15-25
	P<0.3 (instrument pressure)	8-15
	P<0.6 (instrument pressure)	10-20
	P≤2 (instrument pressure)	3-8
Acetylene water		30
Acetylene water		5-6
Acetylene gas	P<0.01 (instrument pressure)	3-4
	P<0.15 (instrument pressure)	4-8
	P<0.25 (instrument pressure)	5
chlorine	gas	10-25
chlorine	liquid	1.6
Hydrogen chloride	gas	20
Hydrogen chloride	liquid	1.5
liquid ammonia	vaccum	0.05-0.3
	P≤0.6 (instrument pressure)	0.3-0.8
	P≤2.0 (instrument pressure)	0.8-1.5
Sodium hydroxide	concentration 0-30%	2
	concentration 30-50%	1.5
	concentration 50-73%	1.2
Sulfuric acid	concentration 88-93%	1.2
Sulfuric acid	concentration 93-100%	1.2
hydrochloric acid		1.5
water and other similar viscosity liquid	P=0.1-0.3 (instrument pressure)	0.5-2
	P≤1.0 (instrument pressure)	0.5-3
	P≤8.0 (instrument pressure)	2-3
	P≤20-30 (instrument pressure)	2-3.5
	Heating network circulating water Cooling water	0.3-1
	pressure backwater	0.5-2
	pressureless backwater	0.5-1.2
tap water	main pipe P=0.3 (instrument pressure)	1.5-3.5
tap water	sub pipe P=0.3 (instrument pressure)	1-1.5
boiler feed water		>3
steam condensate		0.5-1.5
condensate	free flow	0.2-0.5
superheated water		2
seawater and brackish water	P<0.6 (instrument pressure)	1.5-2.5

Note: The unit of DN value is mm; the unit of P value is MPa.
for example:
The resistance coefficient of the gate valve is small, only in the range of 0.1 to 1.5; the resistance coefficient of the large diameter gate valve is 0.2 to 0.5; the resistance coefficient of the narrow gate valve is larger.
The resistance coefficient of the stop valve is much larger than that of the gate valve, generally between 4 and 7.
The resistance coefficient of the Y-type globe valve (DC type) is small, between 1.5 and 2; the resistance coefficient of the forged steel globe valve is large, even as high as 8.
The resistance coefficient of the check valve depends on the structure: the swing check valve is usually about 0.8-2, among which the multi-leaf swing check valve has a large resistance coefficient; the lift check valve has a large resistance coefficient, up to 12 .
The resistance coefficient of the plug valve is small, usually about 0.4 to 1.2.
The resistance coefficient of the diaphragm valve is generally around 2.3.
The drag coefficient of butterfly valve is small, generally within 0.5. The resistance coefficient of the ball valve is small, generally around 0.1.
Note: The resistance coefficient of the above valve is the value when the valve is fully opened. The selection of valve diameter should take into account the machining accuracy and dimensional deviation of the valve, as well as other factors. The valve diameter should have a certain margin, generally 15%. In actual work, the valve diameter depends on the diameter of the process pipeline.

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 and application of stainless steel 430, 304, 316

September 14, 2020

Stainless steel 430, 304,316 are the material of valve body, valve stem/shaft, or valve disc/plate.

lug type butterfly valve body

430 ferritic stainless steel containing more than 12% chromium can prevent oxidation caused by natural factors. It is called stainless steel. It belongs to 430 ferritic stainless steel. It has low thermal expansion rate, excellent formability and oxidation resistance. The code name in JIS is 430, so it is also called 430 stainless steel.

Application of 430 ferritic stainless steel: 430 stainless steel (16Cr) is often used to make household appliances, heat-resistant appliances, burners, home appliances, class 2 tableware, kitchen sinks, exterior decoration materials, bolts, nuts, CD rods, screens .

The difference between 430 stainless steel and 304, 316 austenitic stainless steel: 430 stainless steel and 304, 316 austenitic stainless steel are identified by spectral analysis and chemical element analysis. Both 304 and 316 are austenitic stainless steels. 316 is made of 304 stainless steel with molybdenum added. Therefore, 316 stainless steel has much better seawater and rust resistance than 304.
The difference between 304, 316 and 430 lies in the rust resistance. In addition to chromium, 304 and 316 also contain elements such as nickel and molybdenum, and are non-magnetic. Therefore, the rust resistance of 304/316 austenitic stainless steel is better than 430 stainless steel is much better and the price is much higher. To

Can the 430 stainless steel magnet hold it? 304 and 316 are not magnetic and cannot be attracted by magnets. Generally, it does not generate heat in a high-voltage electromagnetic environment, so it is used more. Martensitic and 430 ferritic stainless steel, precipitation hardening stainless steel are magnetic, and magnets can attract them.

Will 430 stainless steel rust? 430 stainless steel cannot resist the oxidation caused by chemicals in the air. Because there are more and more acidic chemicals in the air, 430 stainless steel will still be oxidized (rusted) due to unnatural factors after being used for a period of time.

Which is better, 430 stainless steel or 304? 304 austenitic stainless steel has excellent corrosion resistance and no magnetism. Relatively speaking, austenitic stainless steel 304 is better than 430 ferritic stainless steel.

How expensive is 430 stainless steel compared to 304? Generally speaking, austenitic stainless steel 304 is twice as expensive as 430 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

Chinese marine valve product standard encyclopedia

September 14, 2020

Marine valves are equipment used to control the pressure, flow and flow direction of fluids in marine pipelines to

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

meet the environmental conditions of ships. A valve is a control device for a fluid pipeline. Its basic function is to connect or cut off the flow of the pipeline medium, change the flow of the medium, change the flow direction of the medium, adjust the pressure and flow of the medium, and protect the normal operation of the pipeline equipment.

GB/T 584 Marine flange cast steel globe valve; GB/T 585 Marine flange cast steel globe check valve; GB/T 586 Marine flange cast steel check valve; GB/T 587 Marine flange bronze globe valve GB /T; 588 marine flange bronze check valve; GB/T 589 marine flange bronze check valve; GB/T 590 marine flange cast iron stop valve; GB/T 59 industrial marine flange cast iron stop check valve; GB/T 592 Marine flange cast iron check valve; GB/T 593 Marine flange bronze and cast iron packing cock; GB/T 594 Marine external thread forged steel globe valve; GB/T 595 Marine external thread bronze globe valve; GB/ T 596 Marine externally threaded bronze check valve; GB/T 597 Marine externally threaded bronze check valve GB/T 598 Marine externally threaded bronze packing cock; GB/T 599 Marine externally threaded bronze discharge cock; GB/T 1241 Marine External thread forged steel stop check valve; GB/T 1850 marine external thread heavy block quick closing valve; GB/T 1852 marine flange cast steel steam pressure reducing valve; GB/T 1853 marine flange cast steel side stop stop Return valve; GB/T 1854 marine flanged cast iron single-row suction stop valve box; GB/T 1855 marine flanged cast iron single-row suction stop check valve box; GB/T 1856 marine flanged cast iron single-row discharge stop valve box; GB/T 1951 Marine low-pressure male-threaded bronze stop valve; GB/T 19 52 Marine low-pressure male-threaded bronze check valve; GB/T 1953 Marine low-pressure male-threaded bronze stop check valve GB/T 2029 Cast steel suction sea valve; GB /T 2030 Bronze suction sea valve; CB/Z 800-2004 GB/T 2032 Marine flanged fire hydrant; GB/T 2499 Marine flanged cast iron double-row globe valve box; GB/T 3036 Marine central butterfly valve; GB/T 3037 Marine double eccentric butterfly valve; GB/T 5744 marine quick closing valve; GB/T 11691 cast steel suction sea valve (four position); GB/T 11692 bronze suction sea valve (four position); GB/T 11696 marine cast steel vertical valve -Shaped check valve; CB/T 304 flanged cast iron right angle safety valve; CB/T 309 marine internal threaded bronze globe valve; CB/T 310 marine internal threaded bronze straight-through check valve; CB/T 311 marine internal threaded bronze packing cock CB 312 pressure gauge valve; CB/T 465 flanged cast iron gate valve CB/T 466 flanged cast steel gate valve CB/T 467 flanged bronze gate valve CB 541 external thread aluminum alloy packing three-way plug CB 557 bronze stop check discharge valve CB 558Pgl 60 male threaded brass air quick start valve CB 561pgl 60 air bottle stop valve CB 563 male threaded aluminum alloy right angle stop valve CB/T 569 marine PM 60 male thread bronze air stop valve CB/T 569 marine PM 60 male thread bronze air stop valve CB 583 flange brass four-way plug CB 584 with check valve high pressure air right angle shut-off valve specification CB 585 with bottom flange right angle blow-off valve CB 587 brass sea valve CB 588 Pg250 diaphragm air right angle shut-off valve CB 589 with Specification for high pressure air right angle shut-off valve with mounting plate CB 590 Specification for high pressure air right angle shut-off valve with mounting plate CB 591 Specification for high pressure air right angle check valve CB 592 with bottom flange Specification for high pressure air right angle shut-off valve CB 593 with bottom flange Specification for high-pressure air right-angle cut-off check valve CB 594 Air right-angle quick-opening valve CB 595 Pg200 air right-angle throttle valve CB 596 Male threaded steel right-angle stop valve CB 597 Male threaded steel right-angle stop check valve CB 598 with bottom flange Male threaded bronze right-angle globe valve CB/T 601 Self-closing drain valve CB/T 624 Water pressure reducing valve CB/T 627 Impact flange cast steel cut-off check valve CB 852 Pg250 Male threaded bronze air straight-through globe valve CB 853 P30 flange cast steel globe valve CB 854 P30 flange bronze globe valve CB 855 P30 flange bronze globe valve CB 898 blowdown side valve CB 900 vertical check valve CB 901 P30 flange bronze gate valve CB 905 emergency tongue Valve CB 907 Male threaded bronze right-angle liquid safety valve CB 909 Angle flap valve CB 1010 Male threaded stainless steel globe valve CB 1049 Double-sided drive emergency side valve CB 3022 Male threaded air signal safety valve CB/T 30 87 flanged cast steel right-angle sea Valve CB 3107 Marine auxiliary boiler feed water stop check valve CB 3124 Pg16 internal thread bronze gate valve CB/T 3191 High pressure manual ball valve CB 3192 external thread steam bronze right-angle safety valve CB/T 3196 flange cast steel seawater stop valve CB/T 3197 method Blue Cast Steel Seawater Stop It Back Valve CB/T 3265 Liquid Level Gauge Self-closing Valve CB 3297 Bellows Type Traps CB/T 3475 Anti-wave Valve CB/T 3476 Vertical Anti-wave Valve CB/T 3477 Closable Vertical Anti-closing Valve Wave valve CB/T 3478 flange suction check valve CB/T 35 91 flange ductile iron tanker gate valve CB/T 3656 marine air pressure reducing valve CB/T 3819 plate lr_E valve CB/T 3841 side Side boiler relief valve CB/T 3843 pressure relief 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

What are the main factors affecting valve sealing?

September 11, 2020

Valve leakage is very common in daily life and industrial production, and the impact is very large. It will cause waste or bring danger to life. For example, the leakage of tap water valve will lead to serious consequences, such as the

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

chemical industry. Toxic, harmful, flammable, explosive and corrosive media leakage, etc., serious threats to personal safety, property safety and environmental pollution accidents. A valve that relies on external force to rotate and drive to open and close is designed with a sealing device. It is used to install a certain number of packing seals in the packing culvert to achieve a sealing effect, but how about the sealing? Leakage at the packing of the valve is one of the most prone to leakage failure in the valve, but the reasons are largely the following reasons.

1. The structure of the sealing pair

The structure of the sealing pair will change when the temperature or sealing force changes. Moreover, this change will affect and change the mutual force between the sealing pairs, thereby reducing the performance of the valve sealing. Therefore, when choosing a seal, be sure to choose a seal with elastic deformation. At the same time, pay attention to the width of the sealing surface. The reason is that the contact surfaces of the sealing pair cannot be completely matched. When the width of the sealing surface increases, the force required for sealing must be increased.

2. The specific pressure of the sealing surface

The specific pressure of the sealing surface affects the sealing performance of the valve and the service life of the valve. Therefore, the specific pressure of the sealing surface is also a very important factor. Under the same conditions, too much specific pressure will cause damage to the valve, but too little wine will cause valve leakage. Therefore, we need to fully consider the appropriateness of the specific pressure when designing.

3. The physical properties of the medium

The physical properties of the medium also affect the sealing performance of the valve. These physical properties include temperature, viscosity and surface hydrophilicity. The temperature change not only affects the slackness of the sealing pair and changes in the size of the parts, but also has an inseparable relationship with the viscosity of the gas. The gas viscosity increases or decreases as the temperature increases or decreases. Therefore, in order to reduce the influence of temperature on the sealing performance of the valve, when we design the sealing pair, we must design it into a valve with thermal compensation such as an elastic valve seat. Viscosity is related to the permeability of the fluid. When under the same conditions, the greater the viscosity, the smaller the permeability of the fluid. The hydrophilicity of the surface means that when there is a thin film on the metal surface, the thin film should be removed. Because this thin oil film will destroy the hydrophilicity of the surface and block the fluid channel.

4. The quality of the sealing pair

The quality of the sealing pair mainly refers to the selection, matching, and manufacturing accuracy of materials. For example, the valve disc and the sealing surface of the valve seat are very consistent, which can improve the sealing performance. The characteristic of many hoop waviness is its good labyrinth sealing performance.

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

Reasons and solutions for leakage of valve sealing surface

September 11, 2020

The valve is the most used control component in the fluid system. It can be used to switch or control the flow

U-type-flange-butterfly-valve-2

direction and adjust the function. From the simplest cut-off function, the valve is sealed in the machine. Its function is to prevent the medium from In the cavity where the part is located, the joint between the parts leaks outward or prevents external substances from entering the inside. The collar and parts that play a sealing role are called seals or sealing structures, or seals for short. The two joint surfaces are in contact with the seal and play a sealing role. The surface is called the sealing surface. The valve sealing surface is the core part of the valve, and its leakage can generally be divided into the following types, namely, leakage of the sealing surface, leakage at the joint of the sealing ring, leakage caused by the fall of the closure member, and leakage of foreign objects embedded between the sealing surfaces. One of the most extensive uses of valves in pipelines and equipment is to cut off the flow of media. Therefore, its tightness is the main factor that determines whether internal leakage occurs. The valve sealing surface is generally composed of a pair of sealing pairs, one on the valve body and the other on the disc.

The reasons for the leakage of the sealing surface are generally as follows:
1. The sealing surface is unevenly ground and cannot form a tight line;
Second, the top center of the connection between the valve stem and the closing member is suspended, incorrect or worn;
3. The valve stem is bent or incorrectly assembled, which makes the closing part skewed or out of alignment;
4. Improper selection of the sealing surface material or failure to select the valve according to the working conditions, the sealing surface is prone to corrosion, erosion and wear;
5. Surfacing and heat treatment are not operated in accordance with the regulations, due to low hardness, wear, corrosion due to burning of alloy elements, and cracks due to excessive internal stress;
Six, the sealing surface after the surface treatment peels off or loses its original performance due to excessive grinding; Seven, the sealing surface is not tightly closed or the crevices appearing due to cold shrinkage after closing, resulting in intermediate corrosion; Eight, treat the shut-off valve as When the throttle valve and pressure reducing valve are used, the sealing surface is eroded and damaged;
9. The valve has reached the fully closed position and continued to apply excessive closing force, including incorrect use of long levers, and the sealing surface was crushed and deformed;
10. Excessive wear of the sealing surface causes disconnection, that is, the sealing pair cannot be tightly sealed;

Prevention and elimination methods of valve sealing surface leakage:
1. When grinding the sealing surface, the grinding tools, abrasives, emery cloth, sandpaper and other objects should use a reasonable grinding method to be correct, and color inspection should be carried out after grinding. The sealing surface should be free of indentation, cracks, scratches and other defects;
2. The connection between the valve stem and the closing member should meet the design requirements. If the top center does not meet the requirements, it should be trimmed. The top center should have a certain movable clearance, especially the axial gap between the valve stem shoulder and the closing member should not be less than 2 Mm;
3. The bend of the valve stem should be straightened. After the valve stem, stem nut, closing parts and valve seat are adjusted, they should be on a common axis;
Fourth, when selecting a valve or replacing the sealing surface, it should meet the working conditions. After the sealing surface is processed, its corrosion resistance, resistance and scratch resistance should be good;
5. The surfacing welding and heat treatment process should meet the technical requirements of the regulations and specifications. After the sealing surface is processed, the acceptance should be carried out. No defects that affect the use are allowed;
Six, the sealing surface surface firing, nitriding, shed infiltration, plating and other processes must be carried out in strict accordance with the technical requirements of its regulations and specifications. The penetration layer of the sealing surface should not exceed one-third of this layer to damage the plating and penetration layer. In serious cases, the plating layer and penetration layer should be removed and the surface treatment should be performed again. The sealing surface of the surface with high frequency smashing can be repeatedly fired and repaired;
Seven, the valve should be marked when it is closed or opened, and it should be repaired in time if the valve is not tightly closed. For high-temperature valves, some slits that appear to be cold-shrinked after closing should be closed more than once at a certain interval after closing;
8. The valve used as a shut-off valve is not allowed to be used as a throttle valve or a pressure reducing valve. The closing part should be in the fully open or fully closed position. When the flow and pressure of the medium need to be adjusted, the throttle valve and reducing valve should be set separately. Pressure valve;
9. The front opening and closing of the valve should comply with the section “Operation of the valve”. The closing force of the valve is appropriate. The diameter of the handwheel is less than 320mm. Only one person is allowed to operate. For handwheels with a diameter equal to or greater than 320mm, two persons or one person are allowed to operate. Operate with leverage within 500 mm;
10. After the waterline drops, it should be adjusted, and the sealing surface that cannot be adjusted should be replaced;

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 main classification and use conditions of valve sealing materials

September 10, 2020

The valve seal is the most important part of the entire valve. Its main purpose is to prevent leakage. The valve sealing

soft sealing marine valve, rubber sealing, valve seat parts

seat is also called a sealing ring. It is an organization that directly contacts the medium in the pipeline and prevents the medium from flowing. When the valve is in use, there are a variety of different media in the pipeline, such as liquid, gas, oil, corrosive media, etc., and different valve seals are used in different places and can adapt to various medium.
Then, valve seal materials can be divided into two major categories, namely, metallic materials and non-metallic materials. Non-metallic seals are generally used for pipelines at room temperature and pressure, while metal seals are widely used and can be used for high temperature and high pressure!
The following briefly introduces the use conditions of various sealing materials and the commonly used valve types.

1. Synthetic rubber
Synthetic rubber is better than natural rubber in oil resistance, temperature resistance and corrosion resistance. Generally, the use temperature of synthetic rubber t≤150℃, natural rubber t≤60℃, and rubber is used for the sealing of stop valves, gate valves, diaphragm valves, butterfly valves, check valves, pinch valves and other valves with a nominal pressure of PN≤1MPa. Commonly used types of synthetic rubber: NBR, EPDM, VITON.
2. Nylon
Nylon has the characteristics of low friction coefficient and good corrosion resistance. Nylon is mostly used for ball valves and globe valves with temperature t≤90℃ and nominal pressure PN≤32MPa.
3. Polytetrafluoroethylene Polytetrafluoroethylene is mostly used for globe valves, gate valves, and ball valves with a temperature t≤232℃ and a nominal pressure of PN≤6.4MPa. Short name: PTFE
4. Cast iron
Cast iron is used for gate valves, stop valves, cock valves, etc. for temperature t≤100℃, nominal pressure PN≤1.6MPa, gas and oil. main types: GI, DI
5. Babbitt alloy
Babbitt alloy is used for ammonia stop valves with temperature t-70~150℃ and nominal pressure PN≤2.5MPa.
6. Copper alloy
Commonly used copper alloy materials include 6-6-3 tin bronze and 58-2-2 manganese brass. Copper alloy has good wear resistance, suitable for water and steam with temperature t≤200℃ and nominal pressure PN≤1.6MPa. It is often used in gate valves, globe valves, check valves, plug valves, etc.
7. Chromium stainless steel
Commonly used grades of chromium stainless steel are 2Cr13 and 3Cr13 after quenching and tempering treatment, which has good corrosion resistance. It is commonly used on valves of water, steam, petroleum and other media with temperature t≤450℃ and nominal pressure PN≤32MPa.
8. Chromium nickel titanium stainless steel
The commonly used grade of chromium nickel titanium stainless steel is 1Cr18Ni9ti, which has good corrosion resistance, erosion resistance and heat resistance. It is suitable for steam, nitric acid and other media with temperature t≤600℃ and nominal pressure PN≤6.4MPa, used in stop valves, ball valves, etc.
9. Nitrided steel
The commonly used grade of nitriding steel is 38CrMoAlA, which has good corrosion resistance and scratch resistance after carburizing treatment. Commonly used for power station gate valves with temperature t≤540℃ and nominal pressure PN≤10MPa.
10. Boronizing
Boronizing is directly processed from the valve body or valve clack body material to form the sealing surface, and then boronizing surface treatment, the sealing surface has good wear resistance. Used in power station blowdown valves. To
When the valve is in use, the matters that should be paid attention to are:
1. The sealing performance of the valve should be tested to ensure its performance.

2. Check whether the sealing surface of the valve is worn, and repair or replace it according to the situation.

Valve material and valve standards-(9)- general valve & parts materials

September 9, 2020

General valve material
The internal material combination specified by API600 for general valve material:

Stem material types	hardness	sealing surface
Stem material types	hardness	seal part no.,	material type	hardness
13Cr	200-275	1	13Cr	≥HB250
		4	13Cr	≥HB750
		5 or 5A	HF	≥HB350
		6	13Cr/NiCu	≥HB750/≥HB175
		7	13Cr/13Cr	≥HB250/≥HB750
		8-8A	13Cr/HF	≥HB250/≥HB350
18Cr-8Ni	no require	2	18Cr-8Ni	no require
25Cr-20Ni		3	25Cr-20Ni
Nickel copper alloy		9	Nickel copper alloy
Nickel copper alloy		11 or 11A	Nickel copper alloy/HF	no require/≥HB350
18Cr-8Ni-Mo		10	18Cr-8Ni-Mo	no require
18Cr-8Ni-Mo		12 or 12A	18Cr-8Ni-Mo/HF	no require/≥HB350
19Cr-29Ni		13	19Cr-29Ni/HF	no require
19Cr-29Ni		14 or 14A	19Cr-29Ni/HF	no require/≥HB350

Commonly used valve trim material combination:

valve stem	sealing surface	valve stem	sealing surface
13Cr	13Cr/13Cr	321	321/321
13Cr	13Cr/STL	321	321/STL
13Cr	STL/STL	321	STL/STL
13Cr	13ZCr/Monel	1Cr18Ni9Ti	1Cr18Ni9Ti/1Cr18Ni9Ti
17-4PH	STL/STL	1Cr18Ni9Ti	1Cr18Ni9Ti/STL
17-4PH	17-4PH/17-4PH	1Cr18Ni9Ti	STL/STL
Monel	Monel/Monel	1Cr18Ni12Mo2Ti	1Cr18Ni12Mo2Ti/1Cr18Ni12Mo2Ti
304	304/304	1Cr18Ni12Mo2Ti	1Cr18Ni12Mo2Ti/STL
304	304/STL	1Cr18Ni12Mo2Ti	STL/STL
304	STL/STL	20 Alloy	20alloy/20alloy
316	316/316	Hastelloy B	Hastelloy B/Hastelloy B
316	316/STL	Hastelloy C	Hastelloy C/Hastelloy C
316	STL/STL	F51	F51/F51
304L	304L/304L	F51	F51/STL
304L	304L/STL	38CrMoALA	STL/STL
304L	STL/STL	25Cr2MoIV A	STL/STL
316L	316L/316L	4Cr10Si2Mo	STL/STL
316L	316L/STL	4Cr14Ni14W2Mo	STL/STL
316L	STL/STL	Inconel	Inconel/Inconel

Commonly used fastener material:

Bolts	Nuts	Max temp °C
35	25	425
35CrMo	35, 45	425
35CrMo	30CrMo	500
25Cr2MoVA	30CrMo	550
0Cr18Ni9	0Cr18Ni9	600
0Cr17Ni12Mo2	0Cr17Ni12Mo2	600
25Cr2Mo1VA	25Cr2Mo1VA	600
25Cr2MoVA	25Cr2MoVA	600

Matching materials of bolts and nuts for American standard valves:

Bolts		nuts		application temp
standard	grade name	standard	grade name	application temp
ASTM A193	B7	ASTM A194	2H	-29/425°C
	B7M		2HM	-29/425°C NACE standard, anti-sulfer valve
	B16		7	-29/593°C
	B8		8	-196/700°C
	B8M		8M	-196/700°C
ASTM A320	L7		4	-46/101°C Cryogenic valve

Chemical composition and mechanical properties of commonly used bolts and nuts for American standard valves:

Chemical composition and mechanical properties of commonly used bolts and nuts for American standard valves

Conditions of use of metal gaskets:

material	HB max	Pressure Mpa(lb)	suitable temp °C
10/08	120	2.0-42(150-2500)	450
0Cr13	170	2.0-15(150-900)	540
0Cr18Ni9	160		600
0Cr17Ni12Mo2	160		600

Spiral wound gasket service conditions:

metal belt material	Non-metallic belt material	Pressure grade Mpa (lb)	suitable temp °C
0Cr18Ni9	flexible graphite	2.0-26(150-1500)	650
0Cr17Ni12Mo2	flexible graphite		650
00Cr17Ni14Mo2	PTFE		200

Conditions for use of metal-clad gasket:

Cladding metal material	HB	filling material	pressure Mpa(lb)	suitable temp °C
Al L3	40	asbestos	2.0-15(150-900)	200
Co T3	60			300
Galvanized steel sheet	90			400
Galvanized steel sheet 08F	90			400
0Cr18Ni9	187			500
00Cr19Ni10
00Cr17Ni14Mo2

Use conditions of flexible graphite composite gasket:

Core board and edging material	pressure grade Mpa (lb)	suitable temp °C
low-carbon steel	2.0-11(150-600)	450
0Cr18Ni9	2.0-11(150-600)	650

Non-metallic gasket usage conditions:

material name	code name	pressure Mpa	suitable temperature °C
natural rubber	NR	2.0	-50/90
Neoprene	CR	2.0	-40/100
NBR	NBR	2.0	-30/110
Ethylbenzene rubber	SBR	2.0	-30/110
EPDM rubber	EPDM	2.0	-40/130
fluororubber	Viton	2.0	-50/200
Asbestos Rubber Sheet	XB350 XB450 NY400	2.0 ≤300 P.T≤650 Mpa °C
Oil-resistant asbestos rubber sheet	XB350 XB450 NY400	2.0 ≤300 P.T≤650 Mpa °C
Modified or filled with PTFE		5.0	-196/260

Comparison table of common metal materials specified by Chinese, Japanese, German, British, American and international standards:

Comparison table of common metal materials specified by Chinese, Japanese, German, British, American and international standards

WC carbon steel +A/B/C –WCA,WCB,WCC

WC carbon steel +ABC –WCA,WCB,WCC

Please see the Full documentation at this link: https://www.tanghaivalve.com/wp-content/uploads/2020/09/valve-material-and-valve-standards-Detailed-version.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

Valve material and valve standards-(8)- Monel alloy application

September 7, 2020

4. Application of Monel alloy:
The A and E levels of M35-1, M35-2 and QQ-N2-88 are usually used to manufacture refined Monel alloy pumps,

buttefly valve stem shaft parts (6)

valves and accessories. The B-grade (3.5%Si) Monel alloy with the highest Si content is mainly used to manufacture shafts and wear-resistant rings that require good wear resistance due to its high strength, corrosion resistance and wear resistance. Class D (4.0% Si) Monel alloy is used to manufacture parts that require higher wear resistance and corrosion resistance.
Monel alloy valves have two types: integral and internal. The integral Monel alloy valve means that the valve shell and internal parts are all Monel, which is mainly used in the HF acid regeneration tower part of the alkylation unit of the refinery. Due to the high HF acid regeneration temperature (149°C) and high water content, an overall alloy valve is required. In addition, the overall Monel alloy valve is also used in the production of ashless additives for catalysts in refineries and high-concentration chlor-alkali systems in chlor-alkali plants. Situation.
The Monel alloy internal valve means that the valve housing is made of carbon steel or stainless steel, and the internal valve is made of Moenl alloy. The Monel alloy valve with carbon steel as the shell is mainly used in the low temperature area of the HF calculation system of the alkylation unit of the refinery. The use of carbon steel is good for low temperature (≤71°C) anhydrous hydrofluoric acid (HF) However, carbon steel will form a film on its surface due to corrosion when used in this working condition for a long time. If carbon steel is used in the valve sealing part, the film formed after corrosion will affect the sealing performance of the valve. It should be pointed out that the commonly used Cr13 type sealing material for carbon steel valves cannot resist the corrosion of HF acid, and the internal material is much cheaper for Monel alloy valves. The Monel alloy valve with carbon steel as the shell can also be used in working conditions such as sea water. The valve housing is made of stainless steel Monel alloy internal valve, which is used in ethylene, propylene, liquid oxygen, pure oxygen, sea water and other working conditions. The monolithic Monel alloy valve and Monel alloy internal valve used in the alkylation unit require a pressure level of CL300 from a safety point of view. The pressure level of Monel alloy internal valve for other working conditions is CL150 and CL300. Or PN116-614Mpa etc.
5. Melting and casting of monel alloy:
The smelting and casting technology of Monel alloy is the key to determine whether the qualified Monel alloy castings can be produced. Because Moenl alloy has developed dendrites, shrinkage cavities and porosity, the tendency of gas absorption (hydrogen absorption, oxygen absorption) is great, and it will Sulfurizing chemical reaction occurs with molding materials. From a safety point of view, Monel alloy valves are required to undergo radiographic inspection in accordance with Class A pipeline valves in highly toxic and dangerous media such as hydrofluoric acid, chlorine and hydrogen chloride gas. . Although the American standard points out that casting M35-1 can be welded, in fact its weldability is extremely poor, and the quality of repaired castings is difficult to guarantee. The density of M35-1 alloy is 8163t/m3 (at 20°C), the solidification shrinkage rate is 21mm/m, and the alloy melting point is 1315-1345°C. The Class A and Class E of M35-1, M35-2 and QQ-N2-88 are delivered as cast. Although there are many grades of cast Monel alloy, when used to cast Monel alloy valve castings, M35-1 in ASTMA494 is mainly used.
Cast Monel alloy and deformed Monel alloy have little change in chemical composition (Table 4), but this change satisfies its better deformability for deformation and gold, while it provides better casting for cast alloys. performance. This is the reason why cast Monel alloy grades are used when casting, and deformed Monel alloy grades are used when selecting rolling materials.
Table 4. Commonly used cast and deformed Monel alloy chemical composition of valves (%)

Grade name	chemical composition /%
Grade name	C	Mn	Si	P	S	Cu	Fe	Ni	others
M35-1	≤0.35	≤1.5	≤1.25	≤0.03	≤0.03	26-33	≤3.5	Ba
Monel400	≤0.30	≤2.0	≤0.5		≤0.024	Ba	≤2.5	63-70
MonelK500	≤0.25	≤1.5	≤0.5		≤0.01	Ba	≤2.0	63-70	Al2.5-3.5, Ti0.35-0.85

6. Conclusion
The current U.S. technical standards for Monel alloys include ASTM, SAE, AMS (American Aeronautical Standards Institute), MIL (U.S. Department of Defense Standards), ANSI, ASME and QQ (American Federal Standards). For the Monel alloy of the same grade, different technical specification systems are adopted, not only the representation method of the grade is different, but the number and content of the specification are not completely the same. Usually military products use MIL, QQ or AMS specifications, and civil products use ASTM and ASME specifications.

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.

Valve material and valve standards-(7)- Monel alloy

September 7, 2020

Monel alloy for corrosion resistant valve
1. Introduction/overview of Monel alloy:
Monel alloy, cast nickel alloy, Hastelloy alloy, etc. are all materials for making special purpose valves. Monel alloy is a Ni-Cu alloy in nickel-based corrosion-resistant alloys. It was first developed by the US Nickel Company. Its typical composition is 70% Ni and 30% Cu. It is the most widely used nickel-based corrosion-resistant alloy.

Monel alloy not only has high strength and toughness, but also has excellent resistance to corrosion by reducing acid and strong alkali media and sea water, so it is usually used to manufacture and transport hydrofluoric acid (HF), salt water, neutral media, and alkali salts. And reducing acid medium equipment. Monel alloy is also suitable for dry chlorine, hydrogen chloride, high temperature chlorine (425°C) and high temperature hydrogen chloride and other media, but it is not resistant to corrosion by sulfur-containing media and oxidizing media (such as nitric acid, media with high oxygen content), and it is nickel It reacts violently with sulfur and oxygen and easily forms Ni3S2 and NiO.

2. Performance of Monel alloy:
Monel alloy is a Ni-Cu solid solution, where Cu is used as a non-oxidizing resist added to Ni, which improves the corrosion resistance of nickel alloys and acts as a strengthening alloy. The addition of C can improve the casting performance of the alloy, but only 0.15% of C can be dissolved in the alloy at room temperature, and the excess C will be precipitated as a graphite phase. Adding 1.5%-3.5% Fe can also improve the casting performance of the alloy. Adding Mn and Si can improve the mechanical properties of the alloy, especially the content of Si has an important influence on the mechanical and physical properties of the Monel alloy.

3. Classification of Monel alloy:
Monel alloys are classified into casting alloys and deformed alloys.
3.1 Deformation alloy: There are more than 10 types of deformed Monel alloys in the United States, such as Monel400, MonelC, Monel403, Monel404, Monel R2405, Monel406, Monel411, MonelK500, MonelK501 and Monel502. Because Monel has its own representation methods in different American standard systems, SAE and ASTM jointly developed ASTM2SAE unified digital system (unified numbt system2 UNS) in order to facilitate the use and unified management of calculations. In the United States’ UNS, nickel alloys have 5 grades of deformed Monel alloys, including solid solution hardened No5500 (Monel400), No4404 (Monel404) and No4405 (MonelR2405), and precipitation hardened NO5500 (MonelK500) and NO5502 (Monel502). ) Etc. (refer to Table 1). Among them, the deformed Monel alloy commonly used in the manufacture of corrosion-resistant valves is Monel400 and MonelK500.
Table 1. Chemical composition of deformed Monel alloy in United States UNS

Grade name	chemical composition/ %
Grade name	C	Si	Mn	S	Ni	Fe	others
NO4400(Monel400)	≤0.3	≤0.5	2	≤0.024	63-70	≤2.5	Cu base
No4404(Monel404)	≤0.15	≤0.1	≤0.1	≤0.024	52-57	≤0.5	Cu base, Al≤0.05
No4405(MonelR2405)	≤0.3	≤0.5	≤2.0	0.025-0.06	63-70	≤2.5	Cu base
No5500(MonelK500)	≤0.25	≤0.5	≤1.5	≤0.01	63-70	≤2	Cu base, Al213-3115,Ti0135-0185
NO5502(Monel502)	≤0.10	≤0.5	≤1.5	≤0.01	63-70	≤2	Cu base, Al215-315

3.2 Casting alloy: The American cast Monel alloy has five grades of M35-1, M35-2, M-30H, M-25S and M-30C in ASTM A494 (Table 2), which is in the US Federal Standard QQ-N2-88 There are also 5 cast Monel alloys (Table 3).
Table 2. Cast Monel alloy in ASTM A494:

grade name

chemical composition /%

mechanical properties

C

Mn

Si

P.S

Cu

Fe

Ni

Nb

Compressive strength/Mpa

Tensile strength/Mpa

Elongation rate/%

HB

M35-1(a)

≤0.35

≤1.5

≤1.25

≤0.03

26-33

≤3.5

Ba

≥450

≥170

≥25

M35-2

≤0.35

≤1.5

≤2.00

≤0.03

26-33

≤3.5

Ba

≥450

≥205

≥25

M-30H

≤0.30

≤1.5

2.7-3.7

≤0.03

27-33

≤3.5

Ba

≥690

≥415

≥10

M-25S

≤0.25

≤1.5

3.5-4.5

≤0.03

27-33

≤3.5

Ba

243-294(b)

M-30C(a)

≤0.30

≤1.5

1.0-2.0

≤0.03

26-33

≤3.5

Ba

1-3

≥450

≥225

≥25

125-130(b)

Notes:
1.Ba=balance, means the balance is all Ni content.
2. To remove the weldability, it should be M3521 or M230C
3. This table is a data parameter
4. HB minimum is 300
Table 3 QQ2N2288 cast Monel alloy:

QQ-N-288	chemical composition /%							mechanical properties
QQ-N-288	C	Si	Mn	Cu	Fe	Ni	Nb	Compressive strength/Mpa	Tensile strength/Mpa	Elongation rate/%	HB
A	≤0.35	≤2.0	≤1.5	26-33	≤2.5	62-68		≥448	≥224	≥25	125-150
B	≤0.30	2.7-3.7	≤1.5	27-33	≤2.5	61-68		≥689	≥455	≥10	240-290
C	≤0.20	3.3-4.5	≤1.5	27-31	≤2.5	≥60		≥825	≥550	≥10	250-300
D	≤0.25	3.5-4.5	≤1.5	27-31	≤2.5	≥60					≥300
E	≤0.30	1.0-2.0	≤1.5	26-33	≤2.5	≥60	1-3	≥448	≥221	≥25	125-150

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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