actuator Archives

Precautions for Wafer type Connecting Dual Plate Check Valve to the Pipeline

September 3, 2024

When installing a wafer-type dual plate check valve in a pipeline, specific precautions must be observed due to its compact design and the way it interfaces with the piping system. Here are the key precautions:

Correct Orientation:

Ensure that the flow direction matches the arrow indicated on the valve body. Installing the valve in the incorrect orientation can prevent it from functioning correctly and may cause damage.

Centering the Valve:

Properly center the wafer-type valve between the flanges to prevent misalignment. Misalignment can lead to uneven sealing, potential leaks, and difficulty in operation.

Gasket Placement:

Ensure the gaskets are correctly positioned and compatible with the valve and flange materials. They should be centered and not protruding into the valve flow area, as this could obstruct the valve plates and affect operation.

Avoid Over-Tightening Bolts:

Tighten the flange bolts in a crisscross pattern to apply even pressure across the valve. Over-tightening can warp the valve body or damage the gaskets, leading to leaks or operational issues.

Pipeline Support:

The pipeline should be properly supported on either side of the valve to avoid placing excessive weight or stress on the valve, which could affect its alignment and functionality.

Check for Obstructions:

Inspect the pipeline for any debris or foreign objects before installation. Ensure that the valve plates can open and close freely without any obstructions.

Correct Valve Sizing:

Verify that the valve is correctly sized for the specific flow rate and pressure conditions of the system. Using a valve that is too large or too small can lead to poor performance or damage.

Even Flange Face Contact:

Ensure that the flange faces are clean, smooth, and parallel to ensure proper sealing. Uneven flange faces can cause leaks or improper seating of the valve.

Avoiding Thermal and Mechanical Stress:

Avoid installing the valve in areas of the pipeline where it might be subjected to excessive mechanical stress, vibrations, or thermal expansion, which could lead to valve failure.

Hydrostatic Testing:

After installation, conduct a hydrostatic test with the valve fully closed to check for leaks. Make sure the pressure applied during testing does not exceed the valve’s pressure rating.

Proper Tools and Handling:

Use appropriate tools for handling and installing the wafer-type valve. Avoid using excessive force or improper tools, which could damage the valve body or internal components.

Accessibility for Maintenance:

Install the valve in a location that allows for easy access for inspection and maintenance. Wafer-type valves often require periodic checks to ensure they are functioning correctly.

Temperature and Pressure Considerations:

Ensure the valve materials are suitable for the operating temperature and pressure of the system. Avoid subjecting the valve to conditions that exceed its design specifications.

Lubrication (if applicable):

Some wafer-type valves may require lubrication of the hinge pin or other components. Follow the manufacturer’s recommendations for any required lubrication.

By carefully following these precautions, you can ensure a secure, leak-free installation and reliable operation of the wafer-type dual plate check valve in your pipeline system.

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Please contact us if you need more support, please contact us freely: info@tanghaivalve.com.We are committed to “Build a top valve enterprise; Be a reliable partner!”Friends from all over the world are welcome to visit us for evaluation, guidance, and orders!

Precautions for Connecting Wafer Butterfly Valve to the Pipeline

August 28, 2024

When connecting a wafer butterfly valve to a pipeline, the following precautions should be taken:

Ensure Proper Alignment: Make sure the valve is correctly aligned between the flanges to avoid any misalignment that could cause leaks or damage to the valve and pipeline.

Check Gasket Positioning: Ensure that gaskets are properly positioned between the valve and flanges to create an effective seal and prevent leakage.

Avoid Over-Tightening Bolts: Tighten the flange bolts evenly in a crisscross pattern to prevent warping of the valve body. Over-tightening can deform the valve or cause the disc to stick.

Disc Position During Installation: Keep the valve disc slightly open during installation to prevent it from contacting the flanges or gaskets, which could damage the disc or interfere with operation.

Verify Compatibility: Ensure the valve’s materials are compatible with the fluid being handled and that the valve’s pressure and temperature ratings match the system requirements.

Pipe Cleanliness: Before installation, clean the pipeline to remove any debris, which could damage the valve seat or disc during operation.

Support the Pipeline: Ensure that the pipeline is properly supported to prevent stress on the valve, which could cause misalignment or leakage.

Flow Direction: Confirm that the valve is installed with the correct flow direction as indicated by the arrow on the valve body.

Final Check: After installation, manually operate the valve to ensure it opens and closes smoothly without obstruction. Conduct a leak test to verify proper sealing.

Tianjin Tanghai Valve Co., Ltd. is a professional marine valve manufacturer, including butterfly valve, check valve, gate /Knife gate valve. We have certificates: CE, ISO, BV, DNV foundry and products approval. Now we have our own independent R & D, manufacturing, assembly and warehousing workshops; we have professional pre-sale and after-sale technical support and perfect services. Below is our wafer butterfly valve of marine valves,if you need to check more information, please click here:https://www.tanghaivalve.com/wafer-type-butterfly-valve-th-btv-aw/.

Please contact us if you need more support, please contact us freely: info@tanghaivalve.com.

We are committed to “Build a top valve enterprise; Be a reliable partner!”Friends from all over the world are welcome to visit us for evaluation, guidance, and orders!

Valve Parameters

August 20, 2024

Nominal Diameter

The nominal diameter (DN) is a numerical designation used to define the size of all piping system components, distinguishing it from those parts that are designated by thread or outside diameter.

Another method for specifying valve sizes is the American system, which uses inches as the unit of measurement. For example, a DN50 valve corresponds to a 2-inch valve.

2.Rounded Numbers

All piping system components with the same nominal pressure (PN) value and the same nominal diameter (DN) have the same connection dimensions that correspond to the type of end connection. In China, when referring to nominal pressure, the unit of measurement is usually specified for clarity and is expressed as “MPa.” In countries like the UK and the US, although the concept of nominal pressure has been included in relevant standards, the imperial unit of pounds per square inch (psi) is still used in practice.

Because the reference temperature for nominal pressure and the pound system differs, there is no strict correlation between them. A general correspondence between them can be found in the table below. The Japanese standard includes a “K” system, such as 10K, 20K, 40K, etc. This pressure rating concept is similar to the pound system in imperial units, but the unit of measurement is metric. The relationship between the “K” rating and the pound system can be found in the table below.

Pressure markings are indicated by “PN” followed by a pressure value (in MPa). For example, PN1.0 indicates a valve with a nominal pressure of 1.0 MPa. However, in everyday use, it is common to refer to a PN10 valve as a 1.0 MPa valve, which is also referred to as a 10 bar/10 kg valve.

3. Common Unit Conversion Relationships

1 inch = 25.4 mm

1 MPa = 10 kgf/cm² (kilogram-force) = 10 bar

1 psi = 0.0069 MPa

1 ksi = 6.9 MPa

Psi: pounds per square inch

kgf/cm²: kilogram-force per square centimeter

Bar: bar

Fahrenheit to Celsius Conversion:

°C = (℉ – 32) * 5/9

Celsius to Fahrenheit Conversion:

℉ = ℃ * 9/5 + 32

Tianjin Tanghai Valve Co., Ltd. is a professional marine valve manufacturer, including butterfly valve, check valve, gate /Knife gate valve. We have certificates: CE, ISO, BV, DNV foundry and products approval. Now we have our own independent R & D, manufacturing, assembly and warehousing workshops; we have professional pre-sale and after-sale technical support and perfect services. Below is our wafer butterfly valve of marine valves,if you need to check more information, please click here: https://www.tanghaivalve.com/wafer-type-butterfly-valve-th-btv-aw/

Please contact us if you need more support, please contact us freely: info@tanghaivalve.com.We are committed to “Build a top valve enterprise; Be a reliable partner!”Friends from all over the world are welcome to visit us for evaluation, guidance, and orders!

Application of Single Door Check Valve

July 17, 2024

A single door check valve, also known as a swing check valve, is used in various applications to allow fluid (liquid or gas) to flow in one direction only and prevent backflow.

ALB Single plate check valve

Wafer stainless steel swing check valve

Here are some common applications:

Water Supply Systems:

To prevent backflow in municipal water supply systems.

In residential plumbing to stop contaminated water from re-entering the clean water supply.

Pumping Systems:

To prevent backflow when the pump is turned off, protecting the pump and avoiding reverse flow that could cause damage.

In sump pump systems to prevent water from flowing back into the sump pit.

Oil and Gas Industry:

In pipelines to ensure one-way flow of oil or gas, preventing backflow that could cause contamination or pressure issues.

In offshore platforms to prevent reverse flow of sea water.

HVAC Systems:

In heating, ventilation, and air conditioning systems to control the direction of refrigerant flow.

In cooling towers to prevent backflow of water.

Chemical Processing:

To ensure the correct flow of chemicals in process lines, preventing contamination and ensuring safe operation.

In acid and alkali handling systems to avoid backflow which could cause reactions or damage.

Marine Applications:

In bilge systems to prevent water from flowing back into the bilge area.

In ballast systems to control the flow of water in and out of ballast tanks.

Fire Protection Systems:

In fire sprinkler systems to ensure water flows in one direction and to prevent backflow which could cause contamination or loss of pressure.

Key Features and Considerations

Non-return function: Prevents reverse flow automatically.

Low-pressure drop: Designed to minimize resistance to flow.

Reliability: Robust and simple design ensures long-term, reliable operation.

Material: Made from various materials like stainless steel, brass, and plastic, depending on the application and fluid type.

Size and Pressure Rating: Available in various sizes and pressure ratings to suit different applications and flow rates.

These valves are essential in systems where maintaining a unidirectional flow is critical for safety, efficiency, and system integrity.

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Standards for Use of Marine Valves

July 9, 2024

Specifies dimensions for metal valves used in marine applications.

butterfuly valve manufacturer

Classification Societies

Classification societies provide additional guidelines and standards specific to marine applications. Some of the major classification societies include:

American Bureau of Shipping (ABS):

ABS Rules for Building and Classing Marine Vessels: Includes requirements for the design, construction, and testing of valves used in marine vessels.

Lloyd’s Register (LR):

Rules and Regulations for the Classification of Ships: Contains specific sections on the requirements for marine valves, including materials, design, and testing.

Bureau Veritas (BV):

Rules for the Classification of Steel Ships: Provides guidelines on the use of valves in marine applications, including specifications for materials and testing.

Det Norske Veritas (DNV):

DNV Rules for Classification of Ships: Outlines the requirements for valves used in marine systems, covering aspects such as design, materials, and performance testing.

National Standards

Different countries may have their own standards and regulations for marine valves. Some notable examples include:

ASTM (American Society for Testing and Materials):

ASTM F1199: Standard Specification for Ferrous Valves for Shipboard Use – Covers the requirements for ferrous valves used on ships.

BS (British Standards):

BS 6364: Valves for cryogenic service – Specifies the requirements for valves used in cryogenic applications, which can be relevant for certain marine applications.

Key Considerations for Marine Valves

Corrosion Resistance: Materials used for marine valves must be highly resistant to corrosion due to exposure to seawater and harsh marine environments.

Pressure and Temperature Ratings: Valves must be able to withstand the specific pressure and temperature conditions encountered in marine systems.

Safety and Reliability: Ensuring that valves operate reliably under the dynamic conditions of marine environments is crucial for safety.

Maintenance and Inspection: Valves should be designed for ease of maintenance and inspection, considering the limited access and challenging conditions on marine vessels.

Compliance and Certification: Marine valves should comply with relevant standards and regulations, and obtaining certification from recognized classification societies is often required.

By adhering to these standards and guidelines, marine valves can provide safe, reliable, and efficient performance in various marine applications, ensuring the safety and operational integrity of marine vessels and structures.

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Please contact us if you need more support, please contact us freely: info@tanghaivalve.com.We are committed to “Build a top valve enterprise; Be a reliable partner!”Friends from all over the world are welcome to visit us for evaluation, guidance, and orders!

Design standards and materials for single door check valves

July 2, 2024

Design Standards for Single Door Check Valves

Single door check valves are designed and manufactured according to various international standards to ensure quality, reliability, and compatibility. Some of the common standards include:

API 594: Covers the requirements for check valves, including design, manufacturing, testing, and inspection.

ASME B16.34: Provides standards for pressure-temperature ratings, dimensions, and materials for valves.

ISO 5752: Standardizes face-to-face and end-to-end dimensions of valves.

BS 1868: Specifies requirements for check valves for petroleum, petrochemical, and allied industries.

DIN 3202: Specifies face-to-face dimensions for valves used in piping systems.

Common Materials Used in Single Door Check Valves

The selection of materials for single door check valves depends on the application, including the type of fluid, operating temperature, and pressure. Common materials include:

6 single-plate-swing-check-valve-2

Body Materials:

Stainless Steel (e.g., 304, 316): Offers excellent corrosion resistance and strength, suitable for a wide range of applications, including aggressive fluids.

Carbon Steel: Provides good strength and durability, commonly used in water, oil, and gas

applications.

Ductile Iron: Combines good strength and impact resistance, often used in water and wastewater applications.

Bronze: Good corrosion resistance, commonly used in marine and potable water applications.

single disc swing check valve body

Stainless Steel: For applications requiring high corrosion resistance.

Carbon Steel: Used for general-purpose applications.

Bronze: Commonly used in applications involving seawater or drinking water.

Composite Materials: Such as reinforced plastics for lightweight and corrosion-resistant applications.

Seat Materials:

Metal Seats (e.g., stainless steel, bronze): Durable and can withstand high temperatures and pressures.

Soft Seats (e.g., EPDM, NBR): Provide better sealing and are used in applications where tight shutoff is required, typically at lower temperatures and pressures.

Spring Materials (if applicable):

Stainless Steel: Commonly used for springs due to its good corrosion resistance and mechanical properties.

Inconel: For high-temperature applications requiring superior strength and corrosion resistance.

Considerations for Material Selection

Corrosion Resistance: Ensure the material can withstand the fluid’s chemical properties.

Temperature and Pressure: The material must be able to handle the operating conditions without degrading.

Mechanical Properties: The material should have the necessary strength and durability for the application.

Regulatory Compliance: Ensure materials meet any regulatory or industry standards required for the application.

By selecting appropriate materials and adhering to design standards, single door check valves can provide reliable and long-lasting performance in a variety of industrial applications.

Tianjin Tanghai Valve Co., Ltd. is a professional marine valve manufacturer, including butterfly valve, check valve, gate /Knife gate valve. We have certificates: CE, ISO, BV, DNV foundry and products approval. Now we have our own independent R & D, manufacturing, assembly and warehousing workshops; we have professional pre-sale and after-sale technical support and perfect services. Below is our wafer butterfly valve of marine valves,if you need to check more information, please click here: https://www.tanghaivalve.com/wafer-type-butterfly-valve-th-btv-aw/

Please contact us if you need more support, please contact us freely: info@tanghaivalve.com.We are committed to “Build a top valve enterprise; Be a reliable partner!”Friends from all over the world are welcome to visit us for evaluation, guidance, and orders!

The Application of Concentric Type Butterfly Valve in Petroleum(oil and gas) Industry

June 25, 2024

Concentric type butterfly valves play vital roles across various sectors within the petroleum (oil and gas) industry due to their reliability, versatility, and cost-effectiveness. Here are the main applications of concentric type butterfly valves in the petroleum industry:

Flow Control in Pipeline Systems:

Crude Oil Pipelines: Regulating the flow of crude oil within pipelines during transportation from production fields to refineries or terminals.

Natural Gas Pipelines: Controlling the flow of natural gas in transmission and distribution pipelines.

Refined Product Pipelines: Managing the flow of refined petroleum products like gasoline, diesel, and jet fuel.

Wellhead and Production Systems:

Flow Control: Regulating the flow of crude oil, natural gas, or water at wellheads and production facilities.

Water Injection Systems: Controlling the injection of water for secondary or tertiary oil recovery methods.

Refining Processes:

Cooling Systems: Regulating the flow of cooling water for heat exchangers and condensers.

Process Fluids: Controlling the flow of various process fluids during refining operations.

Chemical Injection Systems: Regulating the flow of chemicals for process treatment and corrosion inhibition.

Storage Terminal Operations:

Tank Farm Operations: Handling the flow of crude oil, refined products, and

chemicals within storage tank farms.

Loading and Unloading: Controlling the flow of petroleum products during loading onto tankers and unloading from ships or trucks.

Offshore Platforms and Floating Production Systems:

Seawater Systems: Regulating seawater flow for cooling, firewater, and other offshore operations.

Ballast Systems: Controlling ballast water for stability adjustment on offshore platforms.

Firewater Systems: Emergency firefighting systems on offshore platforms.

Petrochemical Plants:

Feedstock Handling: Controlling the flow of feedstocks such as ethylene, propylene, and other petrochemical products.

Process Fluids: Regulating the flow of various chemicals and fluids during production processes.

Key Advantages in the Petroleum Industry:

Corrosion Resistance: Materials selected are often resistant to corrosion from petroleum products and chemicals.

Space Efficiency: Compact design is suitable for installations where space is limited, such as offshore platforms.

Quick Operation: Rapid open/close operation for emergency shutdown situations.

Reliable Sealing: Provides tight shut-off to prevent leaks, crucial for safety and environmental protection.

Cost-Effective Solution: Butterfly valves offer cost savings compared to other valve types.

Concentric type butterfly valves are indispensable components in the petroleum industry, serving critical functions in transportation, production, refining, storage, and distribution of oil and gas products. Their versatility, reliability, and cost-effectiveness make them widely used in various applications throughout the industry. Proper selection, installation, and maintenance of these valves are essential to ensure safe and efficient operations in the petroleum sector.

Tianjin Tanghai Valve Co., Ltd. is a professional marine valve manufacturer, including butterfly valve, check valve, gate /Knife gate valve. We have certificates: CE, ISO, BV, DNV foundry and products approval. Now we have our own independent R & D, manufacturing, assembly and warehousing workshops; we have professional pre-sale and after-sale technical support and perfect services. Below is our wafer butterfly valve of marine valves,if you need to check more information, please click here: https://www.tanghaivalve.com/wafer-type-butterfly-valve-th-btv-aw/，

Please contact us if you need more support, please contact us freely: info@tanghaivalve.com.We are committed to “Build a top valve enterprise; Be a reliable partner!”Friends from all over the world are welcome to visit us for evaluation, guidance, and orders!

Marine valves in the shipbuilding industry（tanghai Valve)

June 7, 2024

Marine valves play a crucial role in shipbuilding, managing the flow of various fluids such as water, fuel, oil, and gases throughout a vessel. These valves are essential for the operational efficiency, safety, and maintenance of a ship. Here are some common types of marine valves used in shipbuilding and their functions:

Gate Valves

Function: Used for on/off control of fluids.

Application: Often used in systems where the valve remains either fully open or fully closed, such as in ballast and bilge systems.

Globe Valves

Function: Used for regulating flow and pressure.

Application: Typically found in cooling water, fuel oil, and lubricating oil systems where flow needs to be controlled.

Ball Valves

Function: Provide tight shut-off and control flow.

Application: Commonly used in low-pressure systems like potable water and compressed air.

Butterfly Valves

Function: Regulate or isolate flow with a rotating disc.

Application: Used in large diameter pipes, such as those in ballast systems, due to their compact design and lightweight.

Check Valves

Function: Prevent backflow.

Application: Installed in bilge lines, ballast systems, and various other systems to ensure one-way flow of fluids.

Safety Relief Valves

Function: Protect systems from overpressure.

Application: Essential in steam systems, hydraulic systems, and any pressurized tanks to release excess pressure.

Control Valves

Function: Regulate flow, pressure, temperature, and level.

Application: Used in automated systems for precise control, often integrated with sensors and actuators.

Diaphragm Valves

Function: Control flow with a flexible diaphragm.

Application: Suitable for corrosive or abrasive fluids, often found in sanitary or chemical systems.

Materials Used

Marine valves must withstand harsh marine environments, including exposure to saltwater, chemicals, and varying temperatures. Common materials include:

Bronze: Excellent corrosion resistance, commonly used for smaller valves.

Brass: Good corrosion resistance and machinability.

Stainless Steel: High strength and corrosion resistance, used in more demanding applications.

Cast Iron: Durable and cost-effective for non-corrosive applications.

Ductile Iron: Offers more strength and flexibility compared to cast iron.

Installation and Maintenance

Installation: Proper installation ensures the longevity and functionality of marine valves. This includes correct orientation, secure mounting, and adherence to manufacturer specifications.

Maintenance: Regular inspections, cleaning, and lubrication are crucial. Valves should be checked for leaks, corrosion, and proper operation. In high-wear applications, routine part replacement might be necessary.

Regulatory Standards

Marine valves must comply with international and national maritime regulations to ensure safety and performance. Key regulatory bodies include:

International Maritime Organization (IMO)

American Bureau of Shipping (ABS)

Lloyd’s Register (LR)

Det Norske Veritas (DNV)

Bureau Veritas (BV)

In summary, marine valves are integral components in shipbuilding, ensuring the safe and efficient operation of various ship systems. Their selection, installation, and maintenance are vital for the vessel’s overall performance and safety.

Tianjin Tanghai Valve Co., Ltd. is a professional marine valve manufacturer, including butterfly valve, check valve, gate /Knife gate valve. We have certificates: CE, ISO, BV, DNV foundry and products approval. Now we have our own independent R & D, manufacturing, assembly and warehousing workshops; we have professional pre-sale and after-sale technical support and perfect services. Below is our wafer butterfly valve of marine valves,if you need to check more information, please click here:https://www.tanghaivalve.com/wafer-type-butterfly-valve-th-btv-aw/.

Please contact us if you need more support, please contact us freely: info@tanghaivalve.com.

We are committed to “Build a top valve enterprise; Be a reliable partner!”Friends from all over the world are welcome to visit us for evaluation, guidance, and orders!

Driving device for Manual Wafer Butterfly Valve

August 31, 2022

The driving device of the manual wafer butterfly valve is mainly the handwheel and the handle. For valves with little torque required for opening and closing, a manual device, handwheel or handle can be used to directly fix the valve stem or valve stem nut. The diameter of the handwheel is based on the relevant standards or the torque required for valve opening and closing. According to the standard, the opening and closing force added to the handwheel or handle cannot exceed 360N, and its shape and size can be in accordance with the provisions of JB/T93-2008. Steel plate, aluminum alloy or plastic pressed handwheels can also be used on manual wafer butterfly valves with smaller nominal size DN. The butterfly valve also has a remote-operated manual device using a universal joint.

JIS 10K-wafer butterfly valve-backup seat (3)

Manual Wafer Butterfly Valve Handle and Turbine Drive
The handle of the manual wafer butterfly valve is mainly used with the gear, while the handwheel needs to be used with the worm drive. When the operating force of the valve exceeds 360N, cylindrical spur gears, bevel gears and worm drive devices are often used to reduce the force required for opening and closing. What’s the difference between a handle and a turbo? The first is that the driving method is different. The turbine butterfly valve mainly drives the rotation of the internal gear through the rotation of the handwheel, so that the valve plate rotates and the valve plate is opened and closed. The handle butterfly valve mainly uses the rotation of the handle to turn the valve plate to open and close. Secondly, the force required to operate the handle is large, so the diameter of the valve used is generally below 250mm. Therefore, the handle of the manual wafer butterfly valve and the turbine drive are also different in nominal diameter.

Operating procedures for the drive device of the manual wafer butterfly valve
1. The operator should be familiar with the structure and working principle of the manual butterfly valve.
2. The opening force of the manual butterfly valve exceeds 15kg. If you feel particularly strenuous, you should eliminate the product failure.
3. When the manual butterfly valve is closed, the handle should be reversed for one or two turns, which is conducive to the reopening of the manual butterfly valve.
4. There will be a sediment accumulation area near the manual butterfly valve that is closed for a long time, and these sediments will form resistance to the opening and closing of the manual butterfly valve.
5. When opening, the opening and closing actions should be repeated to promote the loosening of the sediment.
6. If it is found that there is often sediment deposition near the manual butterfly valve, the manual butterfly valve should be opened and closed frequently to facilitate the removal of sediment.
7. For the manual butterfly valve that does not open and close for a long time, it should also be operated once or twice regularly to prevent rust or silt.
8. Check the shaft end for leakage every six months. If there is leakage, replace the packing in time.

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 is bevel gear?

October 22, 2020

The bevel gear is used to transmit the movement and power between the two intersecting shafts. In general

bevel gear

machinery, the angle of intersection between the two shafts of the bevel gear is equal to 90° (but it may not be equal to 90°). Similar to cylindrical gears, bevel gears have indexing cones, addendum cones, tooth root cones and base cones. The cone has a big end and a small end, and the circle corresponding to the big end is called the index circle (its radius is r), the addendum circle, the root circle and the base circle. The movement of a pair of bevel gears is equivalent to a pair of pitch cones for pure rolling.
Application field
Industrial transmission equipment, vehicle differential
Classification
Straight tooth, helical tooth, curved tooth
Features
Noise reduction, shock absorption, light weight, low cost, etc.

Bevel gear actuator is coded 5 in the valve naming system in China, see link: https://www.tanghaivalve.com/valve-model-establishment-and-meaning/

Unit One , valve type (code name):

butterfly valve	safety valve	Diaph-ragm valve	ball valve	gate valve	check valve	plug valve	Pressure reducing valve	globe valve	filter	Disch-arge valve
D	A	G	Q	Z	H	X	Y	J	GL	FL

Unit two, valve drive mode (code name):

drive mode	Electro-magne-tism	Electro-magnetic hydraulic	Electro-hydraulic	tur-bine	Spur gear	Bevel gear	pneu-matic	Hydr-aulic	Gas-hydr-aulic	elec-tric	han-dle	Hand-wheel
code	0	1	2	3	4	5	6	7	8	9

Unit three, valve connection method (code name):

connection	internal thread	external thread	two different connections	flange	welding	wafer	clamp	ferrule
code	1	2	3	4	6	7	8	9

1. Formation of tooth profile
The formation of the tooth profile of bevel gears is similar to that of cylindrical gears, except that the base cone is

The formation of spherical involute

used instead of the base cylinder. As shown on the right, the generating surface S is tangent to the generatrix of the base cone. When the generating surface S is purely rolling along the base cone, any straight line OK on the

generating surface contacting the generatrix ON of the base cone will form an involute curved surface in space. This curved surface is the tooth profile curved surface of the straight bevel gear. The trajectory of each point on the line OK is an involute (the involute at the vertex O is a point). Each point on the involute NK is equidistant from the cone O, so the involute must be on a spherical surface centered on the cone O and the radius is OK, that is, NK is a spherical involute.
2. Back cone and equivalent gear
The following figure shows a pair of special bevel gear drives. Among them, the number of teeth of wheel 1 is, the indexing circle radius is, and the reference cone angle is; the number of teeth of wheel 2 is, the indexing circle radius is, the indexing cone angle=90°, and the indexing cone surface is A plane, this kind of gear is called a crown gear.

Equivalent gear of bevel gear

The large end node P of the wheel 1 is used as the vertical line of the indexing cone generatrix OP, crossing its axis and point O1, and then taking O1 point as the cone tip and O1P as the generatrix, making a cone tangent to the large end of wheel 1 , Call this cone the back cone of wheel 1. In the same way, the back cone of wheel 2 can be made. Since wheel 2 is a crown wheel, its back cone becomes a cylindrical surface. If the back cones of the two wheels are expanded, the back cone of wheel 1 will be expanded into a sector gear, and the back cone of wheel 2 will be expanded into a rack, that is, after the back cone is expanded, the two are equivalent to gears and teeth. Strip meshing transmission. According to the Fan Cheng principle, when the tooth profile of the rack (that is, the back cone of the crown wheel) is a straight line, the tooth profile of the wheel 2 on the back cone is an involute.

Imagine filling up the gap of the unfolded sector gear, and you will get a cylindrical gear. This imaginary cylindrical gear is called the equivalent gear of the bevel gear, and the number of teeth Zv is called the equivalent number of teeth of the bevel gear. The tooth profile of the equivalent gear and the tooth profile of the bevel gear on the back cone (that is, the big end tooth profile) are consistent, so the modulus and pressure angle of the equivalent gear are consistent with the modulus and pressure angle of the large end of the bevel gear. As for the equivalent number of teeth, it can be obtained as follows:

As can be seen from the figure above, the index circle radius of the equivalent gear of wheel 1 is
γv1=γ1/cosδ1=z1m(2cosδ1)

So
zv1=z1/cosδ1

For any bevel gear there is
zv=z/cosδ

With the help of the concept of bevel gear equivalent gear, the correct meshing condition of a pair of bevel gears should be that the modulus and pressure angle of the large ends of the two wheels are equal respectively; the coincidence degree of a pair of bevel gear transmission can be calculated approximately according to the coincidence degree of the equivalent gear transmission ; In order to avoid undercutting of gear teeth, the minimum number of teeth for bevel gears without undercutting zmin=zvmincosδ
3. Analysis of gear tooth force
Similar to the cylindrical gear, the nominal normal load Fn is decomposed into the circumferential force Ft1, the radial force Fr1 and the axial force Fa1 at the average index circle of the pinion gear. The direction of each force is shown in the figure on the right, and then according to the force balance The geometric relationship between the conditions and the forces is calculated, namely

bevel gear force analysis

Force Analysis of Straight Bevel Gear

The force analysis on the big gear is similar to that on the small gear.
4. Geometric parameters and calculations
Bevel gears use the big end parameter as the standard value, so when calculating their geometric dimensions, the big end should also prevail. As shown in the figure below, the index circle diameters of the two bevel gears are respectively
d1=2Rsinδ1, d2=2Rsinδ2

In the formula, R is the distance from the tip of the indexing cone to the large end, which becomes the cone distance; δ1 and δ2 are the indexing cone angles of the two bevel gears (referred to as the cone angle for short).
The transmission ratio of the two wheels is

i12=w1/w2=z2/z1=d2/d1=sinδ2/sinδ1

When the shaft angle Σ=90° between the two bevel gears, the above formula becomes due to δ1+δ2=90°

i12=w1/w2=z2/z1=d2/d1=cotδ1=tanδ2

Geometry of bevel gear transmission

When designing bevel gear transmission, the value of the cone angle of the two wheels can be determined according to the above formula according to the given transmission ratio.

As for the size of the bevel gear tip cone angle and the tooth root cone angle, they are related to the head clearance requirements of the two bevel gears when they are meshed and driven. According to national standards (GB/T 12369-1990, GB/T12370-1990), equal head-clearance bevel gears are now used for transmission. The head clearance of the two wheels is equal from the big end to the small end of the gear. The cones of the degree cone and the root cone coincide at one point. However, because the generatrix of the tooth tip cone of the two wheels is parallel to the generatrix of the tooth root cone of the other bevel gear meshing with it, the cone tip no longer coincides with the indexing cone cone tip. This kind of bevel gear is equivalent to reducing the tooth tip height of the small end of the tooth, thereby reducing the possibility of the tooth tip being too sharp; and the tooth root fillet radius is larger, which is beneficial to improve the load capacity of the tooth, tool life and storage Oil lubrication.

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