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The role and use of the ball valve

July 16, 2021

The function of the ball valve:
The opening and closing part of the ball valve is a round sphere with a hole. The ball core rotates around the axis of the valve stem by 0-90° back and forth to achieve the purpose of opening or closing the valve. Ball valves have many functions. They are generally used to switch off or adjust the medium in the pipeline. Among them, the three-way ball valve can flexibly cut off, distribute and change the flow direction of the medium. The sealing surface of the ball valve is usually closed with the spherical surface, so it is not easy to be eroded by the medium. It is easy to operate and has a simple and compact structure. It can be used in working conditions such as water, natural gas, acid, and solvent.

fixed ball valve

The application of the ball valve:
Ball valves can generally be divided into three categories: floating ball valves, fixed ball valves, and elastic ball valves according to their structure. According to the different sealing performance, it is divided into hard-sealed ball valves and soft-sealed ball valves. The soft-sealed ball valves have better sealing performance and can achieve zero leakage. They are generally used in normal temperature and pressure pipelines with corrosive media, while hard-sealed ball valves are not only It can be used in normal temperature and pressure, as well as pipelines with low temperature and low pressure and high temperature and high pressure.
(1) Floating ball valve
The ball of the floating ball valve is floating and is supported by two valve seats. Under the action of the medium pressure, the ball can produce a certain displacement and tightly adhere to the sealing surface of the valve seat at the outlet end to ensure that the outlet end is sealed. However, if the sphere bears the load of the working medium and is all transmitted to the outlet sealing ring, the sphere may deviate when it is impacted by a higher pressure. Therefore, the ball valve of this structure is generally suitable for normal pressure or low pressure working conditions.
(2) Fixed ball valve

Pneumatic electric high platform ball valve

The name of the fixed ball valve is that the ball is fixed, and when the valve is closed, the ball valve will not move even if it is pressurized. Fixed ball valves are equipped with a floating seat. After being pressured by the medium, the seat will move so that the sealing ring is pressed tightly on the sphere to ensure sealing. Generally, sliding bearings or rolling bearings are installed on the upper and lower shafts of the ball, which can be operated with a small torque and a small torque, and is generally suitable for high-pressure and large-diameter pipelines.
Other common classifications of ball valves, chip ball valves, orbital ball valves, V-shaped ball valves, O-shaped ball valves, cut-off ball valves, three-way ball valves, four-way ball valves, forged steel ball valves, ash unloading ball valves, anti-sulfur ball valves, eccentric ball valves, thermal insulation ball valves, pneumatic Ball valves, electric ball valves, ferrule ball valves, welded ball valves. Among them, the V-shaped ball valve has a shearing effect, which is especially suitable for media containing fibers, small solid particles, slurry and other media. The three-way ball valve can also be divided into T-type and L-type. The T-shape can make the three intersecting pipelines connect to each other or cut off any one of the channels, playing the role of splitting and merging. The L-shape only connects two perpendicular pipes, and cannot connect to the third pipe at the same time, and it mainly plays a role of distribution.
Related knowledge: working principle of ball valve structure diagram of ball 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

Types and classifications of globe valve

July 16, 2021

Type of globe valve / Classification of globe valve
The globe valve, also called the shut off valve or cut-off valve, is the most widely used valve, which is mainly composed of a valve body, a valve clack, a valve cover, and a valve stem. The valve body and valve cover are pressure-bearing parts, and the valve clack and valve stem are internal parts. The shut-off valve is a valve in which the closing part (disc) moves along the center line of the valve seat. According to this movement form of the valve disc, the change of the valve seat port is proportional to the valve disc stroke.

Classification of stop valves:
According to the structure of the valve body, the globe valve is divided into right-angle type, straight-through type and direct-flow type.
1. The right-angle fluid only needs to change its direction once, so that the pressure drop through this valve is smaller

than that of a conventional shut-off valve. The valve body is mostly forged, which is suitable for shut-off valves with smaller passages and higher pressures.

right-angle Globe valve (2)

2. The straight-through type is the most common structure. The medium inlet and outlet channels are 180° in the same direction, but the fluid resistance is the largest.

straight-through Globe valve (9)

3. In the direct-flow or Y-shaped stop valve, the flow channel of the valve body is in an oblique line with the main flow channel, and the fluid resistance is small. It is mostly used for fluids containing solid particles or high viscosity.

Y-shaped Globe valve (1)

Type of stop valve:
According to nominal pressure: vacuum, low pressure, medium pressure, high pressure, ultra high pressure valve, etc.;
According to working temperature: high temperature, medium temperature, normal temperature, low temperature, ultra-low temperature valve, etc.;

According to the driving mode: manual valve, power driven valve (electromagnetic, pneumatic, hydraulic, electric and various linkage valves), automatic valve, etc.;
According to the valve body material: cast iron, cast copper, cast steel, carbon steel, titanium, stainless steel valves, etc.;
By application sector: general purpose valves, power station valves, marine valves, metallurgical valves, pipeline valves, plumbing valves, etc.;
According to the structure: straight-through type, angle type, direct current type, etc.;
According to the connection form: internal thread, external thread, flange, welding,

clamp, clamp, ferrule, etc.;

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

Globe valve structures and design standard

July 15, 2021

Globe valve structure, Globe valve design standard
The shut-off valve is a particularly common shut-off valve, which is mainly used to connect or cut off the medium in the pipeline, and is generally not used to adjust the flow. The globe valve is suitable for a wide range of pressure and temperature, but it is generally used for medium and small diameter pipelines.

Globe valve (2)

Globe valve (1)

Globe valve (9)

Structural principle of globe valve:
1. The center of the inlet and outlet of the shut-off valve are on the same straight line, and the fluid flows like an S-shaped sphere, so it is also called a spherical shut-off valve.
2. When the valve seat of the valve stem descends toward the bottom sealing surface and is pressed down, the medium stops flowing; when the valve stem rises, the medium passes through the flow path from below to above.
Globe valves generally have direction requirements during installation. The flow direction of the medium in the pipeline generally flows from bottom to top through the valve seat port, which is what we often call the so-called “low inlet and high outlet”. The purpose of this is to reduce fluid resistance and save effort in opening. In the closed state, the valve stem and the packing culvert are not in contact with the medium to ensure that the valve stem and the packing culvert are not damaged or leaked.

Globe valve structure diagram Globe valve structure and design standards:

name	Globe valve structure	Globe valve design standard
Typical Forged Steel Globe Valve	1. Flow channel JB/T 7746-1995: Shrinkage hole BS5352-1999: Through hole or shrinkage hole (CL150~800); Through hole (Cl1500) JPI-7S-36-1999: Through hole 2. Valve body and bonnet Connection: flange, thread or welding 3. Connection end JB/T 7746-1995: internal thread, socket welding or flange BS5362-1999: internal thread, socket, flange and butt welding JPI-7S-36- 1999: Internal thread, socket	JB/T 7746-1995 BS 5352-1999 JPI-7S-36-1999
Internal pressure self-sealing forged steel globe valve	1. Flow path: shrinkage hole 2. Connection between valve body and bonnet: internal pressure self-sealing 3. Connection end: butt welding, flange or socket	ASME B16.34-1996
Cast steel globe valve	1. Flow path: angle type, straight-through, direct current (Y type) 2. Connection between valve body and bonnet: flange 3. Connection end: flange or butt welding 4. Various types of discs can be used, Usually exposed rod, there are also a few smaller diameter valves with dark rod	JPI-7S-46-1999 JIS B2071-1999 JIS B2072-1999 JIS B2081-1999 JIS B2082-1999 BS 1873-1999 MSS-SP-42-1999 GB/T 12235-1989 BS 5160-1989
Bellows Sealed Globe Valve	1. Flow path: angle type, straight-through, direct current (Y type) 2. Connection between valve body and bonnet: flange 3. Connection end: flange or butt welding 4. Various types of discs can be used, It is usually an exposed stem, but there are also a few valves with smaller diameters that use double stem seals with concealed stem 5, bellows and packing	ASME B16.34-1996
Angle type high pressure globe valve	1. Flow path: angle type 2. Connection between valve body and bonnet: thread, clamp or welding 3. Various types of discs can be used. For ultra-high pressure valves, internal pressure self-balancing discs are usually used 4. The valve body can adopt integral type, two-piece type 5. Connection end: flange or butt welding	ASME B16.34-1996 GB/T 12235-1989
Lining stop valve	1. Flow channel: angle type, straight-through, direct current (Y type) 2. Connection between valve body and bonnet: flange 3. Connection end: flange or butt welding 4. Lining material is rubber, plastic, etc.	ASME B16.34-1996
Two-way three-way globe valve	1. Flow path: two-way three-way flow path 2. Connection between valve body and bonnet: flange 3. Connection end: flange or butt welding	ASME B16.34-1996
Cast steel discharge stop valve	1. Flow path: straight-through 2. Connecting end: flange 3. Disc: upward or downward expansion 4. Connection between valve body and bonnet: flange	ASME B16.34-1996
Three-way globe valve	1. Flow path: Tee 2. Connecting end: Flange 3. Disc: Plane seal	ASME B16.34-1996
Pressure gauge shut-off valve	1. Flow path: DC, right angle, three-way 2. Connection between valve body and bonnet: integral forging or thread 3. Connection end: external thread, clamp 4. Disc: Cone and flat	ASME B16.34-1996
Water seal stop valve	1. Flow path: DC 2. Connection end: socket welding, butt welding 3. Valve body and bonnet: both forged, with a chromium nickel steel or carbon steel 4. Disc: Cone seal (DN10~25mm) , Plane seal (DN32~200mm)	E101-1999 GB/T 12235-1999 ASME B16.34-1996
Slurry shut-off valve	1. Flow path: DC 2. Connection end: Flange 3. Valve body structure: The valve seat is clamped between the left and right valve bodies, and the left and right valve bodies are connected by bolts. 4. The valve body and the bracket are connected by bolts. 5. The valve cover: CL150 is forged as a whole, CL300 and CL400 are split type, using strut connection. 6. Disc: Cone surface is sealed into plane seal, or throttle type sealing surface is overlaid with hard alloy	GB/T 12235-1989 ASME B16.34-1996
Angle globe valve	1. Flow path: right angle 2. Connection end: flange 3. Valve body and bonnet: forged throttling type. The sleeve is drilled and the piston moves up and down in the sleeve to adjust the flow. 4. Valve body, valve Cover connection: bolt connection	API 6A-2002
Titanium Globe Valve	1. Flow path: straight-through 2. Valve body, bonnet, stuffing box, valve clack, valve stem are made of titanium 3. Valve body and bonnet connection: bolt connection 4. Valve clack is flat seal	GB/T 12235-1989

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

Schematic diagram of electric ball valve structure

July 14, 2021

The electric ball valve has a simple structure and is composed of a few parts. It has the advantages of small size, light weight, small installation size, small driving torque, easy operation and agility, and it can be quickly opened and closed only by rotating 90°. It has a good flow regulating effect and sealing characteristics; in the application range of large and medium caliber, medium and low pressure, the electric ball valve is one of the leading valves, and it is mainly used to cut off, distribute and change the flow direction of the medium in the pipeline. When the electric ball valve is fully opened, there is no resistance when the medium flows through the ball core port, so the pressure drop that occurs through the valve is very small, so it has better flow control characteristics.

O type ball valve O shaped ball core

Electric ball valve structure: There are many types of electric ball valves, which are generally divided into two categories according to different structural forms, namely O-shaped structure and V-shaped structure. The valve ball openings of the two are different, and the application is also different. O-type is generally suitable for shutting off. Use, occasionally adjust, but V-type is more suitable for adjustment (large adjustable ratio).

O-type ball valve structure:
The O-shaped ball valve is equipped with a ball with a middle through hole inside the valve body. A through hole with the same diameter as the pipe diameter is opened on the ball. When it is fully opened, it is a non-block valve with a large flow capacity and no directionality when fluid enters the valve. The sphere can rotate in the sealing seat, and there is a ring-shaped elastic body on both sides of the pipeline direction to achieve sealing. By rotating the ball 90°, the direction of the through hole can be changed, thereby realizing the opening and closing of the ball valve. ,

V-shaped ball valve structure:

V type ball valve, V-shaped ball core

The V-shaped ball valve core has a V-shaped structure. The valve core is a 1/4 spherical shell with a V-shaped gap. With the rotation of the ball, the opening area changes, but the shape of the opening surface is always triangular, and the flow characteristics are similar. Percentage, the adjustable ratio is large. It has the characteristics of large flow capacity, large adjustable range, shearing force, and tight closing. It is especially suitable for working conditions where fluid materials are fibrous. Generally, V-type ball valves are single-sealed ball valves. Not suitable for bidirectional use.
Related knowledge: The difference between O-shaped ball valve and V-shaped ball valve
Related products: Electric V-shaped ball valve Pneumatic O-shaped ball 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

Globe valve Model Compilation Instructions and Representation Method

July 14, 2021

Model Compilation Instructions for Globe Valves | Representation Method
Compilation instructions for cut-off valve model Description method of cut-off valve model Compilation instructions for cut-off valve model: Cut-off valve, also known as cut-off valve, is a forced-sealing valve. According to the domestic valve model standard, the model of the globe valve is represented by the valve type, drive mode, connection mode,

Globe valve (9)

structure form, sealing material, nominal pressure, and valve body material code. The model of the globe valve is related to the correct understanding of the globe valve product, the importance of the type selection, and the guarantee of the safety of the working conditions. Some of the codes in the following globe valve model compilation are omitted, mainly for the model description of the existing globe valve products. If the material and structure of the customized cut-off valve product changes, please select according to the valve programming method, or call for details.
Representation method of globe valve model:
Additional code for stop valve: W means bellows, D means low temperature, B means heat preservation;
1) Type code of globe valve: J means globe valve;
2) Stop valve transmission mode: manual without code, 5 bevel gear, 6 pneumatic, 9 electric;
3) Connection mode of stop valve: 4 flange connection, 6 welding;
4) The structure of the globe valve: 1 straight-through type, 2 Z-type straight-through, 3 three-way, 4-angle type, 5 Y-type DC type, 6 balanced straight-through type, 7 balanced angle type, 8-pin type;
5) Seal material of globe valve: F fluorine rubber, H stainless steel, N nylon plastic, Y cemented carbide, M Monel alloy, W valve body directly processed;
6) The nominal pressure of the shut-off valve: 16 means that the pressure of 1.6mpa is 16 kilograms, PN1.6-32mpa, IN150LB-1500LB, 5-63K;
7) Globe valve body material: A titanium alloy, C carbon steel, I chromium molybdenum steel, P stainless steel 304,

electric globe valve

R stainless steel 316;
Example of model compilation of globe valve:
J941H-16C Electric Flange Globe Valve
1. J: indicates the stop valve;
2. 9: indicates that the transmission mode is electric;
3. 4: The connection method is flange connection;
4. 1: The structure is a straight flow channel;
5. H: The sealing material is stainless steel;
6. 16: Indicates that the nominal pressure is 1.6MPa;
7. C: Indicates that the valve body material is carbon steel.

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

Electric flange ball valve installation instructions

July 12, 2021

The working principle of the electric flange ball valve is to open and close the valve through the power drive and rotate the valve stem. It has the characteristics of light switch, small size, reliable sealing, simple structure and convenient maintenance. Due to the sealing surface and spherical surface of the electric flange ball valve Often in the closed state, it is not easy to be eroded by the medium, and it is widely used in various industries. As for the correct installation of the electric ball valve is related to the operating conditions of the working conditions and the safety during use, the user should understand the instructions for use.

electric V type ball valve

1. Preparation before installation
1. The front and back pipelines of the electric flange ball valve have been prepared. The front and rear pipes should be coaxial, and the sealing surfaces of the two flanges should be parallel. The pipeline should be able to bear the weight of the ball valve, otherwise the pipeline must be equipped with proper support.
2. Purge the pipelines before and after the valve to remove the oil, welding slag and all other impurities in the pipe belt.
3. Check the mark of the ball valve to find out that the ball valve is intact. Fully open and close the valve several times to verify that it is working properly.
2. Installation method and steps of electric flange ball valve
1. Remove the protective covers on both sides of the flange, and rinse and clean with the valve fully opened.
2. Check the valve hole, and then clean the valve hole. Flush and remove all accumulated impurities in the pipeline (these substances may damage the valve seat and ball).
3. During installation, please do not use the valve stem or handle (handwheel) part of the valve as a fulcrum for lifting objects to avoid collapse and other accidents.

pneumatic-electric-three way ball valve-flange-crew-T-L-type

4. Install the valve on the pipeline. This type of valve can be placed in any position and direction of the pipeline. The two ends are each fixed on a flange piece, and then flange gaskets are added between the two flange plates to fix it.
5. The pipeline near the installation point should not be drooping or bear external forces. Pipe supports or supports can be used to remove the deviation of the pipeline.
6. Finally, use bolts to align the two flange pieces with the flange holes and tighten them to make them tightly connected. (Some pipes or pipe fittings have their own flanges.)
3. Operation and use of electric flange ball valve
1. Make sure that the pipelines and valves have been flushed before operation.
2. The operation of the valve is completed by rotating the valve stem (manual or automatic control mode): when it rotates 1/4 turn (90°) clockwise, the valve is closed. When the reverse rotation is 1/4 turn (90°), the valve opens.
3. When the direction of the handle or the groove on the top of the valve stem is parallel to the pipeline, the valve is open.
4. The torsion of the valve stem will vary according to the following factors: the length of time the valve is opened and closed, the medium of the pipeline system, the pipeline pressure and the type of valve seat, etc.
Related Products: Pneumatic Flanged Ball 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

working principle of electric globe valve

July 12, 2021

The principle of electric globe valve; The working principle of electric globe valve
Overview of electric shut-off valve:
The electric shut-off valve is equipped with an electric actuator on the basis of the shut-off valve, and the opening

electric globe valve

and closing of the valve is controlled by an electric device. The connection between the valve and the actuator adopts a direct connection method. The electric actuator has a built-in servo system, no need to be equipped with a servo amplifier, input 4-20mA signal and 220VAC power supply to control the operation. It has the advantages of simple connection, compact structure, small size, light weight, low resistance, stable and reliable action, etc. It can also be operated manually on site according to requirements, with the actuator with hands and electric switching mechanism. In addition to local operations, remote operations can also be performed.
Working principle of electric shut-off valve:
The closing principle of the electric shut-off valve is to rely on the electric thrust to rotate the valve stem, so that the sealing surface of the disc and the sealing surface of the valve seat are closely attached to prevent the medium from flowing. The electric shut-off valve only allows the medium to flow in one direction and is directional when installed. The structural length of the shut-off 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.
1 In the closed position, the valve body is mechanically pressed by the valve stem, and the sealing surface of the valve clack is tightly pressed on the valve seat.
2 When turning the handwheel counterclockwise, the valve stem moves in the opposite direction, and the bottom angle plane makes the valve body separate from the valve seat.
3 The valve stem continues to lift, and interacts with the guide pin in the spiral groove of the valve stem, so that the valve flap starts to rotate without friction.
4 Until it reaches the fully open position, the valve stem is raised to the limit position and rotated to the fully open position.
Parameters of electric shut-off valve:
Valve material: cast iron, cast steel, stainless steel, forged steel, forged stainless steel, chromium molybdenum steel, low temperature steel.
Working pressure: 1.6-32MPa
Working temperature: -196°C-550°C
Valve diameter: DN15-DN800 Connection method: flange, wire or welding
Drive mode: electric
Applicable medium: water, oil, gas, steam, etc.
Application areas: mechanical equipment, chemical equipment, general parts, industrial equipment, water supply and drainage equipment, papermaking equipment, pharmaceutical equipment, general equipment, petrochemical equipment, power equipment, metallurgical powder equipment, mining equipment, municipal, electronic industry, etc.

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 and maintenance of electric ball valve

July 9, 2021

Installation and maintenance of electric ball valve
Electric ball valve is a kind of valve used to control the pipeline medium and can realize remote control. It is an important equipment in the current industrial automation control system. Including pneumatic ball valves, and other valves cannot be used continuously. After storage or use for a certain period of time, if you want to continue to ensure its effective work and appropriately extend its service life, maintenance and maintenance must be done.
Electric ball valve installation and maintenance:

electric ball valve

1. When the electric ball valve is closed, there is still pressurized fluid inside the valve body;
2. Before maintenance, release the pipeline pressure and keep the valve in the open position; disconnect the power or air source; separate the actuator from the bracket;
3. It is necessary to find out that the upstream and downstream pipelines of the electric ball valve have indeed been relieved of pressure before the disassembly and decomposition operations can be carried out;
4. Care must be taken to prevent damage to the sealing surface of parts, especially non-metal parts, when disassembling and reassembling. Special tools should be used when removing O-rings;
5. The bolts on the flange must be tightened symmetrically, gradually and evenly during assembly;
6. The cleaning agent should be compatible with the rubber parts, plastic parts, metal parts and working medium (such as gas) in the ball valve. When the working medium is gas, gasoline (GB484-89) can be used to clean the metal parts. Clean non-metal parts with pure water or alcohol;
7. The decomposed individual parts can be cleaned by dipping. Metal parts with undecomposed non-metal parts can be scrubbed with a clean, fine silk cloth impregnated with cleaning agent (to prevent fibers from falling off and adhering to the parts). When cleaning, remove all grease, dirt, glue, dust, etc. adhering to the wall;
8. After cleaning, the non-metal parts should be taken out of the cleaning agent immediately, and should not be soaked for a long time;
9. After cleaning, it needs to be assembled after the cleaning agent of the washed wall surface is volatilized (can be wiped with a silk cloth not soaked in cleaning agent), but it should not be left for a long time, otherwise it will rust and be contaminated by dust;
10. New parts also need to be cleaned before assembling;
11. Use grease to lubricate. Grease should be compatible with ball valve metal materials, rubber parts, plastic parts and working medium. When the working medium is gas, for example, special 221 grease can be used. Apply a thin layer of grease on the surface of the seal installation groove, apply a thin layer of grease on the rubber seal, and apply a thin layer of grease on the sealing surface and friction surface of the valve stem;
12. Metal chips, fibers, grease (except those specified for use), dust, other impurities, foreign objects, etc., should not be allowed to contaminate, adhere or stay on the surface of the parts or enter the cavity during assembly.

Related knowledge: Pneumatic ball valve installation instructions

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

bellows globe valve structure and features

July 9, 2021

Bellows globe valve structure (picture), the function and characteristics of bellows globe valve
Bellows globe valve structure:
Bellows cut-off valve is mainly filled with a bellows seal. The upper part of the outer surface of the bellows is welded to the valve body to form a closed space in which the liquid is contained. The valve stem is inserted into the bellows, and the bottom of the bellows is connected to the valve core. The expansion and contraction of the bellows controls the opening of the valve core. Therefore, if the bellows does not crack, there can be no leakage. The bellows has a very high sealing reliability and can be used in toxic media or gases. Such as chlorine. Prevent leakage.

Globe valve (9)

Structural characteristics of bellows globe valve:
1. Double sealing design (bellows + packing) If the bellows fails, the stem packing will also avoid leakage and meet international sealing standards
2. There is no fluid loss, reducing energy loss and improving plant equipment safety
3. Long service life, reduce maintenance times and lower operating costs
4. Rugged and durable bellows seal design to ensure zero leakage of the valve stem and provide maintenance-free conditions
5. The gas medium valve seat adopts PTFE soft sealing material to improve the sealing performance of this valve
6. High temperature resistance≤425℃The valve seat adopts conical hard seal. Achieve airtight performance and zero leakage

The function of the bellows globe valve:

The function of the bellows in the globe valve is to seal and prevent the medium from leaking from the valve stem. The lower end of the bellows and the valve stem are connected by sealing welding, the upper end and the gland are connected by sealing welding, and the gland is connected with the upper Metal spiral wound gaskets are generally installed between the flanges to ensure sealing. The bellows shut-off valve is extremely tight and rarely leaks.

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

Structural characteristics & features of flanged butterfly valves

July 8, 2021

The basic knowledge and structural characteristics of flange butterfly valves:
The flanged butterfly valve has introduced a self-sealing design concept, in which the connection between the disc and the valve shaft adopts a patented pull-out pin structure. The main features of the valve are reliable sealing, bi-directional sealing, and tight connection without loosening, so that the valve can be used for a long time. Its characteristics are as follows:

Double flange butterfly valve (16)

Two-way sealing
Generally, traditional butterfly valves cannot be sealed well under the working pressure in the opposite direction (not conducive to the sealing direction) due to their structural reasons. At present, the relevant national standards do not have mandatory regulations for two-way sealing. This is because:
1. Adopting the self-sealing design concept. The disc sealing ring is directly embedded in the disc in a zigzag shape with rubber, and there is no need to use pressure rings or bolts to fix, thus avoiding the uneven force of the sealing ring caused by the traditional bolt pressure plate type seal, which makes the bolts The problem of falling off and premature damage to the sealing ring. Under the action of the working pressure in the opposite direction, the sealing ring generates self-sealing force, which increases the specific pressure of the seal. The sealing ring compresses the valve seat. The greater the working pressure in the opposite direction, the greater the self-sealing force, so that the sealing ring and the valve seat The combination is tight to achieve the effect of two-way sealing.

triple offset butterfly valve-double flange- (4)

2. The disc has good rigidity and is not easy to deform. The disc of butterfly valve above DN300 is a double-plate truss flow-through structure, with small flow resistance and good rigidity. Under the working pressure in the opposite direction, it is not easy to deform, so that the sealing ring will not follow the disc Deformed and separated from the best sealing point of the valve seat, thus ensuring the sealing effect of the sealing ring.
3. Long life of rubber sealing ring
(1) Due to the self-sealing design concept, the small interference between the rubber ring and the stainless steel valve seat only maintains the initial seal, so the specific pressure required for the seal increases with the increase of the system pressure.
(2) In addition, there is a so-called “breathing” groove for rubber elastic retreat in the zigzag groove, so that the rubber has a certain expansion space when it is under pressure, so that it will not produce elastic fatigue during long-term work, so it is sealed The life of the ring is greatly increased compared with the traditional type.
Patent design withdrawal pin structure
Usually in the process of using the butterfly valve, due to the traditional pin connection, the pin passes through the center of the valve shaft, which not only reduces the strength of the valve shaft, but also creates a gap between the valve shaft and the valve shaft during long-term use, which will cause an impact when the valve is opened and closed. Load, this load is much greater than the load generated by the extrusion stress and shear stress under normal conditions. Often the pin is severely deformed or broken during use, which makes the valve closed or fails, and greatly reduces the valve Service life. If the newly produced valve adopts the US patent design withdrawing pin structure to replace the pin connection structure between the shaft and the valve disc, the withdrawal pin does not pass through the center of the valve shaft, not only does not weaken the strength of the shaft, but also connects with the valve shaft. The fitting surface is greatly increased. By tightening the withdrawal pin nut, a pre-tightening force is generated between the withdrawal pin and the valve shaft joint surface, so that the disc valve shaft is tightly combined without gaps, and it will not be used when opening and closing the valve. The impact load is generated, so that the valve flap rotates smoothly, thereby realizing reliable sealing.
Unique design of the bottom axial adjustment and locking device
In butterfly valves above DN300, considering the reliability of the self-weight seal of the butterfly plate, the position of the disc on the valve seat is in the best sealing state through precise adjustment and fixation of the axial position during manufacturing. For the sagging of the valve clack that may be caused during long-term use, it is also convenient to further adjust the lock to achieve zero leakage in long-term use.
Easy to replace the sealing ring
When the sealing ring needs to be replaced, there is no need to remove the disc, just open the valve fully, and then take out the key from the operating device, after the operating device is adjusted to the closed state, it still maintains the key connection with the main valve, and then continues in the opening direction Turn the hand wheel until the sealing ring is on the side of the valve body sealing surface to replace the sealing ring.
Related knowledge: the principle of butterfly valve structure
Related products: Electric flanged butterfly valve Pneumatic flanged butterfly valve

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

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