butterfly valve manufacturer Archives

Notes on selection and installation of butterfly valve

July 17, 2020

Product selection points of butterfly valves:
1. The main control parameter of the butterfly valve is the size.
2. The butterfly valve is a single-plate air valve. It has a simple structure, convenient processing, low cost, and easy operation, but the adjustment accuracy is poor. It

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

is only suitable for the occasion of switching or rough adjustment in the ventilation and air conditioning system.
3. It can be operated manually, electrically or by zipper, and can be fixed at any angle in the range of 90°.
4. Due to the single shaft and single valve plate, the bearing capacity is limited, and the service life of the valve is short under the condition of large pressure difference and large flow rate. The valve is divided into closed type and ordinary type, thermal insulation and non-thermal insulation.
5. The electric butterfly valve has only two-position control, and the electric actuator is the same as the multi-leaf valve.

Installation matters of butterfly valve:
The butterfly valve has a simple structure, small volume, light weight, and relatively few components. The key parts can form a butterfly valve. It is also very convenient to open. You only need to select the switch to ninety degrees. The butterfly valve The fluid control is very good, you can increase or decrease the flow at any time, the valve has a certain resistance when transporting any fluid, and the resistance of the butterfly valve mainly comes from its own, such as the thickness of the butterfly valve body, if you want to reduce the fluid The resistance only needs to reduce its thickness.
Elastic seals have the disadvantage of being limited by temperature.
Butterfly valves are also widely used. If they are used to control the flow rate, different types and sizes of valve bodies need to be selected, because butterfly valves are more suitable for valves with larger diameters when they are designed. Butterfly valves are not only widely used in general industries such as petroleum, gas, chemical, and water treatment, but also in cooling water systems of thermal power stations.

Tianjin Tanghai dongyang valve Co., Ltd. is one of the largest butterfly valve manufacturers in China, main products are butterfly valves, check valves. Product ranges: 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…)

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

How to choose the right butterfly valve (2)

July 13, 2020

However, the following problems still exist during the use of this butterfly valve:
1. Due to the multi-layer soft and hard laminated seal ring fixed on the valve plate, when the valve plate is normally open, the medium forms a frontal flush on the sealing surface. The soft sealing tape in the metal sheet interlayer is directly affected by the flushing, which directly affects the sealing performance.

U-type flange butterfly valve, ductile iron, DI, center line,

2. Restricted by structural conditions, the structure is not suitable for valves with a diameter of DN200 or less, because the overall structure of the valve plate is too thick and the flow resistance is large.
3. Due to the principle of the three-eccentric structure, the sealing between the sealing surface of the valve plate and the valve seat is caused by the torque of the transmission device to press the valve plate against the valve seat. In the positive flow state, the higher the medium pressure, the tighter the seal extrusion. When the medium in the flow channel reverses flow, as the medium pressure increases, the unit positive pressure between the valve plate and the valve seat is less than the medium pressure, and the seal begins to leak.

The high-performance triple-eccentric bidirectional hard seal butterfly valve is characterized in that the valve seat sealing ring is composed of multiple layers of stainless steel sheets on both sides of a soft T-shaped sealing ring. The sealing surface of the valve plate and the valve seat is an oblique cone structure. The surface of the oblique cone of the valve plate is welded with a temperature-resistant and corrosion-resistant alloy material; the spring fixed between the pressure plate of the adjustment ring and the adjustment bolt of the pressure plate are assembled together.
This structure effectively compensates the tolerance zone between the shaft sleeve and the valve body and the elastic deformation of the valve stem under medium pressure, and solves the sealing problem of the valve in the process of bidirectional interchangeable medium transportation. The use of soft T-shaped multi-layer stainless steel sheets on both sides to form a sealing ring has the dual advantages of metal hard seal and soft seal. It has zero leakage sealing performance at low and high temperatures.
The test proves that when the pool is in the positive flow state (the medium flow direction is the same as the disc rotation direction), the pressure on the sealing surface is generated by the torque of the transmission device and the effect of the medium pressure on the valve plate. When the positive medium pressure increases, the tighter the surface of the valve plate oblique cone and the valve seat sealing surface are pressed, the better the sealing effect. In the reverse flow state, the seal between the valve plate and the valve seat is pressed against the valve seat by the torque of the driving device. As the pressure of the reverse medium increases, the unit positive pressure between the valve plate and the valve seat is less than the medium pressure, the deformation energy stored by the spring of the adjusting ring after being loaded compensates the tight pressure of the sealing surface of the valve plate and the valve seat Play the role of automatic compensation. Therefore, unlike the prior art, the utility model does not install soft and hard multi-layer sealing rings on the valve plate, but directly installs on the valve body. It is an ideal two-way hard sealing method to add an adjustment ring between the pressure plate and the valve seat. . It will replace gate valves, globe valves and ball valves.

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

The main classification methods of butterfly valve (1)

July 10, 2020

There are several classification methods of butterfly valves.

According to the driving method
(1) Electric butterfly valve

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(2) Pneumatic butterfly valve
(3) Hydraulic butterfly valve
(4) Manual butterfly valve
According to the structure:
(1) Center sealed butterfly valve
(2) Single eccentric sealed butterfly valve
(3) Double eccentric seal butterfly valve
(4) Triple eccentric seal butterfly valve

Sealing surface material:
(1) Soft seal butterfly valve.
1) The sealing pair is composed of non-metallic soft materials versus non-metallic soft materials.
2) The sealing pair is composed of metal hard material to non-metal soft material.
(2) Metal hard seal butterfly valve. The sealing pair is composed of metal hard material to metal hard material.
According to the sealing form:
(1) Forced sealing of butterfly valve.
1) Elastic sealing butterfly valve: The sealing specific pressure is caused by the valve plate squeezing the valve seat when the valve is closed, resulting in the elasticity of the valve seat or valve plate.
2) Impressed torque sealing butterfly valve: The sealing specific pressure is generated by the torque applied to the valve shaft.
(2) Pressure-filled sealing butterfly valve: The sealing specific pressure is generated by the pressure-filling of the elastic sealing element of the valve seat or valve plate.
(3) Automatic sealing butterfly valve: The sealing specific pressure is automatically generated by the medium pressure.

According to working pressure:
(1) Vacuum butterfly valve. Butterfly valve with working pressure lower than standard stack atmospheric pressure.
(2) Low-pressure butterfly valve. Butterfly valve with nominal pressure PN<1.6MPa.
(3) Medium pressure butterfly valve. Butterfly valve with a nominal pressure PN of 2.5-6.4 MPa.
(4) High-pressure butterfly valve. Butterfly valve with a nominal pressure PN of 10.0-80. 0MPa.
(5) Ultra-high pressure butterfly valve. Butterfly valve with nominal pressure PN>100MPa.

According to working temperature:
(1) High temperature. Butterfly valve with t>450 °C.
(2) Medium temperature butterfly valve. Butterfly valve with 120 C<t<450 ℃.
(3) Normal temperature butterfly valve. A butterfly valve at 40C<t<120 °C.
(4) Low temperature butterfly valve. A 100<t<- 40 °C butterfly valve.
(5) Ultra-low temperature butterfly valve. Butterfly valve with t<-100 °C.

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

The advantages and disadvantages of butterfly valves

July 10, 2020

Advantages of butterfly valve:

1. Convenient opening and closing, labor saving, low fluid resistance, and can be operated frequently.

wafer type butterfly valve, NBR seat (11)

2. The structure is simple, the external dimensions are small, the structural length is short, the volume is small, and the weight is light. It is suitable for valves with large diameter.

3. Mud can be transported, and the least liquid is accumulated in the pipe mouth.

4. Under low pressure, a good seal can be achieved.

5. Good adjustment performance.

6. When fully opened, the effective flow area of the valve seat channel is large, and the fluid resistance is small.

7. The opening and closing torque is small, because the butterfly plates on both sides of the rotating shaft are basically the same under the action of the medium, and the direction of generating torque is opposite, so the opening and closing are more labor-saving.

8. The sealing surface material is generally rubber, plastic, so the low-pressure sealing performance is good.

9. Easy installation.

10. Flexible and labor-saving operation, you can choose manual, electric, pneumatic, hydraulic mode.

Disadvantages of butterfly valve:

1. The operating pressure and operating temperature range are small.

2. Poor sealing.

Butterfly valves can be divided into offset plate type, vertical plate type, inclined plate type and lever type according to the structure.

According to the sealing form, it can be soft-sealed or hard-sealed. The soft seal type generally uses a rubber ring seal, and the hard seal type usually uses a metal ring seal.

According to the connection type, it can be divided into flange connection and wafer connection; according to the transmission mode, it can be divided into manual, gear transmission, pneumatic, hydraulic and electric.

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

Posts

Notes on selection and installation of butterfly valve

How to choose the right butterfly valve (2)

The main classification methods of butterfly valve (1)

The advantages and disadvantages of butterfly valves

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