check valve Archives

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

Principles of valve selection in the petroleum and chemical industry

September 14, 2020

Faced with so many valve classifications and such complex various working conditions, to choose the most suitable

lug type butterfly valve, ductile iron, center lined,

valve product for piping system installation, you should first understand the characteristics of the valve; secondly, you should master the steps and basis for selecting the valve; and then you should follow the choice of oil , The principle of valves used in the chemical industry. The principle of selecting valves in the petroleum and chemical industries: the flow path is a straight-through valve, and its flow resistance is small, and it is usually selected as a shut-off and open medium valve; a valve that is easy to adjust the flow is used as a control flow; a plug valve and a ball valve are more suitable Used for reversing and shunting; the sliding of the closing part along the sealing surface of the valve with wiping effect is most suitable for the medium with suspended particles.

1. Valves for shut-off and open media: The flow channel is a straight-through valve with low flow resistance. It is usually selected as a valve for shut-off and open media. The downward closing valve (stop valve, plunger valve) is less used because of its tortuous flow path and higher flow resistance than other valves. Where higher flow resistance is allowed, a closed valve can be used.

Globe valve (9)

2. Valves used for flow control: Generally, valves that are easy to adjust flow are selected as flow control valves. Downward closing valves (such as globe valves) are suitable for this purpose because the size of its seat is proportional to the stroke of the closing member. Rotary valves (plug valves, butterfly valves, ball valves) and flex-body valves (pinch valves, diaphragm valves) can also be used for throttling control, but they are usually only applicable in a limited range of valve diameters. The gate valve uses a disc-shaped gate to cross-cut the circular valve seat port. It can only control the flow better when it is close to the closed position, so it is usually not used for flow control. 3. Valves for reversing and shunting According to the needs of reversing and shunting, this kind of valve can have three or more channels. Plug valves and ball valves are more suitable for this purpose. Therefore, most of the valves used for reversing and splitting use one of the plug valves and ball valves. However, in some cases, other types of valves can also be used for reversing and shunting as long as two or more valves are properly connected to each other.

4. Valves for medium with suspended particles When there are suspended particles in the medium, it is most suitable for valves with a wiping effect on the sliding of the closing part along the sealing surface. If the back and forth movement of the closing member to the valve seat is vertical, it may hold particles. Therefore, unless the sealing surface material allows particles to be embedded, this valve is only suitable for basic clean media. Ball valves, plug valves, and butterfly valves have a wiping effect on the sealing surface during opening and closing, so they are suitable for use in media with suspended particles.

At present, no matter in the pipeline system of petroleum, chemical industry, or other industries, valve applications, operating frequencies and services are ever-changing. To control or eliminate even low-level leakage, the most important and critical equipment is still valves. The ultimate control of the pipeline is the valve. The service and reliable performance of the valve in various industries are unique.

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

Description of valve pressure& installation direction requirements

September 14, 2020

As the name implies, the pressure of the valve refers to the pressure that the valve can withstand, that is, the

double-wing-check-valve-3

pressure level of the valve is not lower than the design pressure level of the pipeline. The pressure-bearing direction refers to the closed state of the valve after the valve is applied to the pipeline conditions. The arrow direction of the valve body is the recommended pressure-bearing direction. If it is installed incorrectly, the leakage failure of the valve may not be tightly closed. Generally, it is determined according to the use process or usage conditions. The same direction refers to the pressure-bearing direction (the side with high medium pressure on both sides of the valve gate) and the flow direction, and the opposite direction refers to the pressure-bearing direction (both sides of the valve gate) The side with high medium pressure) is opposite to the flow direction of the medium.

Many valves are directional, such as stop valves, throttle valves, pressure reducing valves, check valves, etc. If they are installed upside down, they will affect the use effect and life (such as throttle valves), or they will not work at all (such as Pressure reducing valve), or even cause danger (such as check valve). Normal valves have direction signs on the valve body; if not, they should be correctly identified according to the working principle of the valve.

The arrow marked on the valve body is the recommended pressure direction of the valve, not the flow direction of the pipeline medium. Valves with two-way sealing function may not be marked with an indicating arrow, or with an arrow, because the valve arrow refers to the recommended pressure direction. It is better to have one direction in the left and right or up and down directions. Usually used by the engineering installation company as the medium flow direction to mark the wrong installation, resulting in leakage or even pipeline accidents;

The valve cavity of the shut-off valve is asymmetrical left and right. The fluid must pass through the valve port from bottom to top, so that the fluid resistance is small (determined by the shape), and the opening is labor-saving (because the medium pressure is upward), and the medium does not press the packing after closing, which is convenient for maintenance . This is the reason why the globe valve cannot be reversed. Other valves also have their own characteristics. The location of the valve installation must be convenient for operation; even if the installation is temporarily difficult, it is necessary to consider the long-term work of the operator. It is best to keep the valve handwheel flush with the chest (usually 1.2 meters away from the operating floor), so that it is easier to open and close the valve. The hand wheel of the floor valve should be upward, not tilted, to avoid awkward operation. To

The valve of the wall machine and the equipment should also leave room for the operator to stand. It is necessary to avoid operating from the sky, especially acid and alkali, toxic media, etc., otherwise it is very unsafe. Do not install the gate valve upside down (that is, the handwheel is downward), otherwise the medium will remain in the valve cover space for a long time, which will easily corrode the valve stem, and it is contraindicated by certain process requirements. At the same time, it is extremely inconvenient to replace the packing. The exposed stem gate valve should not be installed underground, otherwise the exposed stem will be corroded due to moisture. When installing the lift check valve, ensure that its valve flap is vertical for flexible lifting. For the swing check valve, ensure that its pin shaft is level during installation to allow flexible swing. The pressure reducing valve should be installed upright on a horizontal pipe, and not inclined in all directions.

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

Installation attentions for valves

August 18, 2020

Precautions for valve installation:

Globe valves, throttle valves, pressure reducing valves, check valves and other valves are all directional. If the throttle valve is installed upside down, it will affect the use effect and life. If the pressure reducing valve does not work at all, if it is stopped The return valve can even cause danger.

lift-swing-check-valve-2

Generally, the valve has a direction mark on the valve body; if not, it should be correctly identified according to the working principle of the valve.

The valve cavity of the shut-off valve is asymmetrical left and right, and the fluid must pass through the valve port from bottom to top, so that the fluid resistance is small (determined by the shape), and the opening is labor-saving (due to the upward pressure of the medium), and the medium does not press the packing after closing, which is convenient for maintenance . This is the reason why the globe valve cannot be reversed. Other valves also have their own characteristics.

The valve installation location must be convenient for operation; even if the installation is temporarily difficult, it is necessary to consider the long-term work of the operator.

It is best to keep the valve hand wheel flush with the chest (usually 1.2 meters away from the operating floor), so that opening and closing the valve is easier. The hand wheel of the floor valve should be upward, do not tilt, to avoid

Globe valve (9)

awkward operation. The valve of the wall machine and the equipment should also leave room for the operator to stand. It is necessary to avoid operating from the sky, especially acid and alkali, toxic media, etc., otherwise it is very unsafe.

Do not install the gate valve upside down (that is, the handwheel is down), otherwise the medium will remain in the valve cover space for a long time, which will easily corrode the valve stem, and it is taboo for certain process requirements. At the same time, it is extremely inconvenient to replace the packing.

1. The pressure reducing valve should be installed upright on the horizontal pipeline, and not inclined in all directions.

2. As for the lift check valve, make sure its valve flap is vertical when installing it so that it can be lifted flexibly.

3. Swing check valve, ensure that its pin shaft is level when installing, so that it can swing flexibly.

4. Do not install the rising stem gate valve underground, otherwise the exposed stem will be corroded due to moisture.

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…)

The difference between globe valve and check valve

August 13, 2020

With the development of high-tech industry, various valves are often used in daily life. Today we will understand the difference between globe valves and check valves.

The difference between globe valve and check valve:
1. Check valve and stop valve are not the same thing, the difference between the two is mainly that the structure is

Globe valve (6)

very different.

2. The check valve is a one-way valve, which automatically prevents the fluid from flowing in the reverse direction, without a knob, and cannot artificially block the forward flow.

3. The stop valve has a knob, which can artificially control the forward flow. Due to its special structure, even if there is no artificial pipe valve, the fluid cannot flow in the reverse direction.

Globe valve:

The globe valve, also known as the shut-off valve, is a forced sealing valve, so when the valve is closed, pressure must be applied to the disc to force the sealing surface to not leak. When the medium enters the valve from below the valve

lift-swing-check-valve-2

disc, the resistance that the operating force needs to overcome is the friction force of the valve stem and the packing and the thrust generated by the pressure of the medium. The force of closing the valve is greater than the force of opening the valve, so the valve stem The diameter of the valve must be large, otherwise the valve stem will bend failure.
working principle of globe valve:
The globe valve, also called the cut-off valve, is one of the most widely used valves. The reason why it is so popular is that the friction between the sealing surfaces is small during the opening and closing process, which is relatively durable, has a low opening height, and is easy to manufacture. , Easy maintenance, not only suitable for medium and low pressure, but also suitable for high pressure. The closing principle of the globe valve is to rely on the pressure of the valve stem to make the sealing surface of the disc and the sealing surface of the valve seat tightly fit to prevent the medium from flowing. Our country’s valve “Sanhua” once stipulated that the flow direction of the stop valve should be from top to bottom, so there is directionality when installing. The structural length of the stop valve is longer than that of the gate valve, and the fluid resistance is large, and the sealing reliability is not strong during long-term operation.

Check valve:

Check valve refers to the valve that automatically opens and closes the disc depending on the flow of the medium itself to prevent the medium from flowing back, also known as check valve, one-way valve, reverse flow valve, and back pressure valve. Check valve is a kind of automatic valve, its main function is to prevent the back flow of the medium, prevent the pump and drive motor from reversing, and the discharge of the container medium.

working principle of check valve:
Check valve refers to the valve that automatically opens and closes the disc depending on the flow of the medium itself to prevent the medium from flowing back. It is also called check valve, one-way valve, reverse flow valve and back pressure valve. Check valve is a kind of automatic valve, its main function is to prevent the back flow of the medium, prevent the pump and drive motor from reversing, and the discharge of the container medium. The check valve can also be used to supply the auxiliary system whose pressure may rise above the system pressure. Check valves can be divided into swing check valves (rotating according to the center of gravity) and lift check valves (moving along the axis).

Valve manufacturers recommend:
Tanghai Valve Factory is a technological enterprise that produces globe valves and check valves. It designs and produces according to your needs, and provides you with professional, high-quality, low-priced valve products. Welcome to call us for quotations.

Features and working principle of silent check valve

August 11, 2020

Silent check valve refers to a valve that automatically opens and closes the disc depending on the flow of the medium itself to prevent the medium from flowing back. It is also called check valve, one-way valve, silence check valve, reverse flow valve, and back pressure valve. Check valve is a kind of automatic valve, its main function is to prevent the back flow of the medium, prevent the pump and drive motor from reversing, and discharge the container medium. Check valves can also be used to supply pipelines for auxiliary systems whose pressure may rise above the system pressure. Check valves can be divided into swing check valves (rotating according to the center of gravity) and lift check valves (moving along the axis).
Features of silent check valve:
1. The valve clack adopts a “bullet” shape design, and the valve body adopts a “waist drum” shape design to improve the flow direction of the medium and reduce the flow resistance coefficient.

2. The valve adopts a short structure. Although the head loss is slightly larger than that of the lift-type silent check valve, it is small in size and inexpensive.

3. Compact structure, non-metallic lubrication sleeve is installed between the guide shaft and the guide frame, and the valve flap can be raised and lowered flexibly without locking phenomenon.

4. The skeleton type rubber sealing ring is directly embedded in the valve body, which avoids the direct erosion of the sealing ring by the medium for a long time, and the service life is si

silent check valve (11)

gnificantly prolonged, and it is strong and durable.

5. The valve flap has a short opening and closing stroke, which can effectively prevent water hammer

6. It is suitable for water supply and drainage system and high-rise building pipe network. It can be installed at the outlet of the pump. The structure is slightly modified, and it can be used as a suction bottom valve, but it is not suitable for sewage pipe network.

7. It has small size, light weight, low fluid resistance, fatigue resistance and long life
working principle of silent check valve:
When the medium flows in the specified direction, the valve flap is opened by the force of the medium; when the medium flows backward, the valve flap is tightly closed with the sealing surface of the valve seat due to the weight of the valve flap and the opposing force of the medium. Closed to achieve the purpose of preventing the backflow of the medium.

Check valve is an automatic valve, its main function is to prevent the back flow of the medium, prevent the pump and drive motor from reversing, and the release of the container medium. Check valves can also be used to supply pipelines for auxiliary systems whose pressure may rise above the system pressure.

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

Y type ball check valves’ work theory, construction feature, advantage

August 11, 2020

1. Overview of ball check valve:
Ball type check valve is widely used in petroleum, chemical and electric heating boilers and other devices. It is

fig.01-ball check valve drawing

mainly used to prevent the reverse flow of the medium in the pipeline and protect the safe operation of the equipment. It is an ideal non-return device for pipelines. However, the current common check valve structures include swing type and lift type. Because these common check valves have problems such as easy sticking, poor sealing, difficult to repair, and may cause serious shutdown when they close by themselves. The valve water hammer phenomenon, and the water hammer pressure far exceeds the system working pressure, so the system safety may be endangered. Therefore, in addition to meeting the basic requirements of flow, the design of the check valve is the most important thing is the size of the flow resistance, whether there is leakage or vortex, which is related to energy consumption, and at the same time affects the level of production cost and product competitiveness. This new ball check valve is designed based on the theory of reducing flow resistance and eliminating water hammer.
2. Working principle of ball check valve:
The ball check valve shown in Figure 1 includes a valve body, a valve seat 2, a valve cover 7, and a valve disc. The valve body is composed of a left valve body 5 and a right valve body 1. The right valve body is the medium inlet end, and the left valve body The body is the outlet end of the medium. The valve seat 2 is installed between the left valve body 5 and the right valve body 1. The valve disc is a ball 3, and the sealing surface of the valve seat 2 is a spherical surface that cooperates with the surface of the ball 3. The left valve body is composed of a fluid channel and a ball track. The centerline of the sphere track forms an acute angle with the centerline of the fluid channel, and the angle design of the acute angle is determined according to the flexible rise and fall of the valve flap 3 in the sphere track. An arc-shaped filter screen 6 is arranged at the intersecting line of the fluid channel and the sphere orbit. The arc-shaped filter screen 6 has the same curvature as the inner circular wall of the sphere orbit, so that the inner arc of the arc-shaped filter screen 6 and the inner circular wall of the sphere orbit are formed The integral inner cylindrical surface constitutes a smooth rolling passage for the valve flap 3, which does not affect the flow of the medium, and enables the valve flap 3 to roll flexibly. This valve uses media thrust and disc gravity to automatically control the rolling position of the ball in the ball track. When the medium flows in the forward direction, the media thrust pushes the disc to the upper end of the ball track. When the positive thrust of the medium disappears, the disc moves from the ball track. The upper end rolls off and fits the valve seat sealingly, which has the advantages of simple structure, the ball is not easy to be stuck in the ball track, the sealing reliability is good, and the water hammer is small.
3. Structural features of ball check valve:

fig.2-ball check valve 3D schematic

The ball check valve has no transmission parts in structure and has a free opening and closing structure, so there is no wear of the shaft and sleeve. The valve flap automatically rotates in the ball orbit, and the sealing surface is always updated, and there is no fixed wear point. The ball surface wears evenly during the working process, and always maintains a high shape accuracy. The use performance will not decrease with the passage of time, which improves the service life of the seal. The surface of the valve disc is lined with rubber, and the dimensional accuracy and surface roughness of the ball can be controlled by the rubber lined mold. The processing accuracy of the ball is reduced, and it can be reused, which reduces the cost of the disc. The surface rubber of the steel ball will elastically deform, can absorb and dampen vibration, and play a certain buffering effect. The low density of rubber makes the inertia of the disc movement small and the movement is sensitive. The sphere adopts a hollow structure and is light in weight, which reduces the impact force of the valve disc on the valve seat when it is closed. The inner diameter of the sphere track is designed to be larger than the pipe diameter of the corresponding flange, which increases the flow cross section, reduces the medium resistance and reduces the pressure. When the sealing structure is designed according to the corresponding flange, the working pressure is from vacuum to medium pressure. Under the premise of not being restricted by installation conditions, the ball check valve can be installed horizontally or vertically. Moreover, the valve is easy to maintain in the pipeline, and only needs to replace the lower disc.
4. Conclusion of ball check valve:
In accordance with DIN EN 12266 “Pressure Test of Valves” and corporate standards, the series of ball check valves have been inspected and tested. As a result of the test, the technical performance parameters fully meet the design requirements. The application of this valve improves the safety factor of other equipment on the pipeline, with low flow resistance, flexible opening and closing, and good sealing performance, which is welcomed by users. This valve is also equipped with a curved filter screen to purify the medium. One valve has multiple functions, meeting customers’ multi-functional requirements, and greatly reducing customer costs.

Ball check valve introduction

August 10, 2020

Check valves are also known as counterflow valves, check valves, back pressure valves, and one-way valves. This kind of valve is automatically opened and closed by the force generated by the flow of the medium itself in the pipeline, and belongs to an automatic valve.

Uses and characteristics of ball check valve:

ball check valve (9)

HQ44X single-ball micro-resistance ball check valve and HQ45X double-ball micro-resistance ball check valve all use rubber covered balls as the disc. Their principle is that under the action of the medium, they can roll back and forth on the slide in the valve body, thereby Play to open or close the valve. The main features of HQ44X single-ball micro-resistance ball check valve and HQ45X double-ball micro-resistance ball check valve are large flow, small flow resistance pressure loss, good sealing performance, silencing closure, and reduction of water hammer waves. It can be installed horizontally or vertically. The micro-resistance ball check valve can be used at the pump outlets of cold water, hot water, industrial and domestic sewage pipe networks to prevent the medium from flowing back. In order to prevent the medium from flowing back, check valves should be installed on equipment, devices and pipelines

Ball check valve is also called reverse valve, check valve, back pressure valve, one-way valve. This kind of valve is automatically opened and closed by the force generated by the flow of the medium itself in the pipeline, and belongs to an automatic valve. The check valve is used in the piping system, and its main function is to prevent the medium from flowing back, preventing the pump and its driving motor from reversing, and to discharge the medium in the container. Check valves can also be used to supply pipelines for auxiliary systems whose pressure may rise above the pressure of the main system.

Product advantages of ball check valve:
1. The fluid resistance is small. The ball check valve is the smallest fluid resistance of all valves. Even the reduced diameter ball valve has relatively small fluid resistance.

2. The check valve is opened and closed quickly and conveniently. As long as the valve stem rotates 90°, the ball valve completes the fully open or fully closed action, which is easy to achieve rapid opening and closing.

3. Good sealing performance. Spherical check valve seat sealing ring is generally made of elastic materials such as polytetrafluoroethylene, which is easy to ensure sealing, and the sealing force of the ball valve increases with the increase of medium pressure.

4. The valve stem is sealed reliably. The valve stem only rotates when the ball valve is opened and closed, so the packing seal of the valve stem is not easily damaged, and the sealing force of the reverse seal of the valve stem increases with the increase of medium pressure.

5. The opening and closing of the ball valve can only be rotated by 90°, so it is easy to realize automatic control and remote control. The ball valve can be equipped with pneumatic device, electric device, hydraulic device, gas-liquid linkage device or electro-hydraulic linkage device.

6. The spherical check valve channel is flat and smooth, and it is not easy to deposit media, and the pipeline can be ball-passed.

Introduction of Carbon steel lift check valve H41H-16C

August 10, 2020

H41H-16C carbon steel lift check valve (check valve) is also known as one-way valve or check valve. Its opening and

lift-swing-check-valve-2

closing parts are opened or closed by the flow and force of the medium, and its function is to prevent the medium in the pipeline from flowing back .
check valve can be divided into three types according to the structure: lift check valve, swing check valve and butterfly check valve. Lift check valves can be divided into two types: vertical and horizontal; swing check valves are divided into three types: single, double and multiple; butterfly check valves are straight-through. The above-mentioned check valves can be divided into threaded connection, flange connection, wafer type and welding in connection form.
Attention to the installation of H41H-16C carbon steel lift check valve:
1. Do not allow the check valve to bear weight in the pipeline, and the large check valve should be independently supported so that it is not affected by the pressure generated by the pipeline system.
2. When installing, pay attention to the direction of medium flow should be consistent with the direction of the arrow marked on the valve body.
3. Lifting vertical flap check valve should be installed on the vertical pipeline.
4. Lifting horizontal flap check valve should be installed on the horizontal pipeline.

The products of Tianjin Tanghai Valve Manufacturing Co., Ltd. are:
1. Lift check valve: materials include cast iron, cast steel, stainless steel, chromium molybdenum steel; pressure: 1.0-16Mpa; connection methods include threaded connection, flange connection, welding; nominal pass: DN25-1200
Such as: cast steel lift check valve H41H-16C; stainless steel lift check valve H41W-16P; water pump bottom valve H42W-10/H42H-16C/H42W-16P.
Silence check valve HC41T-10; Silent check valve H42T-10; Spherical check valve HQ41X-10; Vertical fluorine-lined check valve H42F-10; Fluorine-lined lift check valve H41F46-16C; Wafer Muffler check valve H71T-10; Welded check valve H61H/Y-160
2. Swing check valve: the materials are cast iron, cast steel, stainless steel, chromium molybdenum steel; pressure: 1.0-16Mpa; connection methods include threaded connection, flange connection, welding; nominal passage: DN25-1200
Such as: cast steel swing check valve H44H-16C; stainless steel swing check valve H44W-16P; cast iron swing check valve H44T-10; rubber flap swing check valve HC44X-10; threaded connection Swing check valve H14H-16C/H14W-16P/H14T-10, H74W/F-16P.
3. Butterfly check valve: the materials are cast iron, cast steel, stainless steel, chromium molybdenum steel; pressure: 1.0-16Mpa; connection methods include threaded connection, flange connection, welding; nominal diameter: DN25-1200
Such as: double disc butterfly check valve H76H-16C/H76W-16P; micro resistance slow closing check valve HH47H-16C/HH48H-16C/HH49H-16C

To ensure your requirements, please specify when ordering:
1. For new project users, please provide the model designed by the design institute, and for replacement parts users, please provide the product model used before
2. If there is no specific model, please provide: 1. Use medium and temperature; 2. Working pressure; 3. Transmission method; 4. Connection method; 5. Structure form;
6. Nominal diameter, etc.
To
H41H-16C carbon steel lift check valve model, performance parameters, structure size parameters, price and other details. (Note: All text, data, and pictures in this article are for reference only. If you need detailed parameters, please call Senpin Company. With professional technology, professional manufacturing, and professional services, Tanghai Valve is committed to meeting user expectations , Constantly improve service quality, keep improving, “Sincere Service” is the eternal theme of Senpin. If you need help, please contact our sales Harry Li.)

TH VALVE is one of the largest butterfly valve manufacturers in China, main products are butterfly valves, check valves. 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.

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