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Medium temperature for butterfly valves of different materials

In the large number of butterfly valve enquiries made by Tanghai Valve every day, “medium temperature” is a frequently mentioned term. Because the different types of media have a great influence on the selection of valve varieties. Whether the medium is an ordinary liquid, a highly corrosive special medium, or a cement-like turbid

Double flange butterfly valve (7)

Double flange butterfly valve (7)

medium, all correspond to different valve types. Whether the medium is high temperature or low temperature also determines which material of the butterfly valve is more suitable and durable. Now let’s take a look at the medium temperature of various butterfly valve materials.
The main material involved here is the body and bonnet material of the butterfly valve. The corresponding medium temperature is as follows:
Cast iron-the highest temperature of the applicable medium is 300℃;
Nodular cast iron-the highest temperature of the applicable medium is 350℃;
Stainless steel ——The highest temperature of applicable medium is 600℃;
Polytetrafluoroethylene——Maximum operating temperature of applicable medium: -180~150℃;
Rubber —— The highest operating temperature of the applicable medium: natural rubber 60℃; nitrile rubber and neoprene rubber 80℃; fluorine rubber 150℃. When the valve lining is made of rubber or plastic, its temperature resistance shall prevail.
Gray cast iron-the highest temperature of the applicable medium is 250℃;
High silicon cast iron-the highest temperature of the applicable medium is 120℃;
Carbon steel-the highest temperature of the applicable medium is 425℃ (if 16Mn, 30Mn forgings can reach 450℃);
Alloy steel-the highest temperature of the applicable medium is 550℃;
Copper alloy-the highest temperature of the applicable medium is 200℃;
Titanium-the highest temperature of the applicable medium is 300℃;
In addition, there are relatively special ceramic and glass butterfly valves, which have poor temperature resistance and are generally used below 90°C. The temperature resistance of the enamel valve is limited by the material of the sealing ring, and the maximum medium temperature exceeds 150℃.
Among the above various butterfly valve materials, cast iron butterfly valves, spheroidal ink butterfly valves, stainless steel butterfly valves, PTFE butterfly valves, and rubber butterfly valves are widely used and have better overall performance. They also occupy a large number of daily orders for Tanghai valves. The proportion of products is very popular in the market. Tanghai Valve produces butterfly valve products of various specifications and materials. With 24 years of industry experience, I believe you will definitely choose your favorite high-quality butterfly valve here.

TH Valve is a professional manufacturer of butterfly valvegate valvecheck valveglobe valveknife 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

Related news/knowledge:
Applicable occasions and application conditions of butterfly valves
Applicable occasions and operation method of ball valve
Valve body and material classification

Classification of valves

Valve classification by function and purpose:

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

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

(1) Cut-off type: such as gate valve, globe valve, plug valve, ball valve, butterfly valve, needle valve, diaphragm valve, etc. The cut-off valve is also called a closed-circuit valve or a cut-off valve, whose function is to connect or cut off the medium in the pipeline.

Check valve, also known as one-way valve or check valve, check valve is an automatic valve, its function is to prevent the back flow of the medium in the pipeline, prevent the pump and drive motor from reversing, and the leakage of the container medium . The bottom valve of the pump to close the water is also a check valve.

Explosion-proof valves, emergency valves, etc. The role of safety valves is to prevent the pressure of the medium in the pipeline or device from exceeding the specified value, so as to achieve the purpose of safety protection.

Regulating valve, throttle valve and pressure reducing valve, its role is to adjust the pressure, flow and other parameters of the medium.

(2) Vacuum: such as vacuum ball valve, vacuum baffle valve, vacuum charging valve, pneumatic vacuum valve, etc. Its role is in the vacuum system to change

The vacuum system components that adjust the air flow direction, cut off or connect the pipeline are called vacuum valves.

(3) Special purpose categories: such as pigging valve, vent valve, drain valve, exhaust valve, filter, etc. The exhaust valve is an indispensable auxiliary component in the pipeline system, which is widely used in boilers, air conditioners, oil and gas, and water supply and drainage pipelines. It is often installed at high points or elbows to remove excess gas in the pipeline, improve the efficiency of pipeline use and reduce energy consumption.

According to the main parameters:

According to the nominal pressure:

lug type butterfly valve, ductile iron, center lined,

lug type butterfly valve, ductile iron, center lined,

  • (1) Vacuum valve: refers to a valve whose working pressure is lower than the standard atmospheric pressure.
  • (2) Low pressure valve: refers to the valve with a nominal pressure PN ≤ 1.6Mpa.
  • (3) Medium pressure valve: refers to valves with nominal pressure PN of 2.5Mpa, 4.0Mpa, 6.4Mpa.
  • (4) High-pressure valve: refers to the valve whose nominal pressure PN is 10.0Mpa~80.0Mpa.
  • (5) Ultra-high pressure valve: refers to a valve with a nominal pressure PN≥100.0Mpa.
  • (6) Filter: Refers to the nominal pressure PN is 1.0Mpa, 1.6Mpa

According to working temperature

  • (1) Ultra-low temperature valve: used for valves with medium working temperature t<-101℃.
  • (2) Normal temperature valve: used for valves with medium working temperature -29℃<t<120℃.
  • (3) Medium temperature valve: used for valves with a working temperature of 120℃<t<425℃.
  • (4) High temperature valve: used for valves with medium working temperature t>425℃.

By driving method:

According to the driving mode, it is divided into automatic valves, power-driven valves and manual valves

Valves driven by compressed air. Hydraulic valve: A valve driven by the pressure of liquids such as oil.

In addition, there are combinations of the above several driving methods, such as pneumatic-electric valves.

According to the nominal diameter:

  • (1) Small diameter valve: Valve with nominal diameter DN≤40mm.
  • (2) Middle diameter valve: a valve whose nominal diameter DN is 50~300mm.
  • (3) Large diameter valve: a valve with a nominal valve DN of 350~1200mm.
  • (4) Extra large diameter valves: valves with nominal diameter DN ≥ 1400mm

6. According to structural characteristics:

Valve structure characteristics:

The structural features of the valve can be divided into:

  • (1) Sectional gate shape: The closing part moves along the center of the valve seat; such as a globe valve
  • (2) Cock and ball: The closing part is a plunger or a ball, which rotates around its own centerline; such as a plug valve, a ball valve
  • (3) Gate shape: The closing part moves along the center of the vertical valve seat; such as gate valve, gate, etc.
  • (4) Swing shape: The closing part rotates around the axis outside the valve seat; such as swing check valve, etc.
  • (5) Butterfly shape: the disc of the closing part, which rotates around the axis in the valve seat; such as butterfly valve, butterfly check valve, etc.
  • (6) Slide valve shape: The closing piece slides in a direction perpendicular to the channel. Slippery

Press connection method:

  • (1) Threaded connection valve: The valve body has an internal thread or an external thread, which is connected with the pipe thread…
  • (2) Flange connection valve: The valve body has a flange and is connected to the pipeline flange.
  • (3) Welding connection valve: The valve body has a welding groove and is welded to the pipeline.
  • (4) Clamp connection valve: The valve body has a clamp, which is connected with the pipe clamp.
  • (5) Ferrule connection valve: the ferrule is connected to the pipeline.
  • (6) Wafer connection valve: a connection form in which the valve and two pipes are directly clamped together with bolts.

According to the body material

  • (1) Metal material valve: its valve body and other parts are made of metal material. Such as cast iron valves, cast steel valves, alloy steel valves, copper alloy valves, aluminum alloy valves, lead alloy valves, titanium alloy valves, Monel alloy valves, etc.
  • (2) Non-metallic material valve: its valve body and other parts are made of non-metallic material. Such as plastic valves, enamel valves, ceramic valves, FRP valves, etc.

TH Valve is a professional manufacturer of butterfly valvegate valvecheck valveglobe valveknife 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

Related news/knowledge:
Notes on selection and installation of butterfly valve;
Classification of check valves;
Classification and advantages of gate valve;
The main classification methods of butterfly valve (1)

Common failures of butterfly valves and the characteristics of installation

Common errors of butterfly valves:
The rubber elastomer in the butterfly valve will tear, wear, aging, perforate or even fall off during continuous use. The traditional thermal vulcanization process is

Double flange butterfly valve (16)

Double flange butterfly valve (16)

difficult to meet the needs of on-site repair. Special equipment is used for repair, which consumes a lot of heat and electricity, which takes time and effort. Today, we use new method gradually of adopting polymer composite materials to replace traditional methods. The superior adhesion and excellent wear and tear resistance of its products ensure that the repair cycle reaches or even exceeds the life cycle of new parts, greatly reducing downtime.

Installation and maintenance of butterfly valves:
1. During installation, the valve disc should stop at the closed position.
2. The opening position should be determined according to the rotation angle of the butterfly valve disc.
3. Butterfly valves with bypass valves should be opened before opening.
4. The installation should be carried out according to the manufacturer’s installation instructions. The heavy butterfly valve should be installed with a solid foundation.

Construction and installation points
1. The installation position, height, and direction of entrance and exit must meet the design requirements, and the connection should be firm and tight. The handles of all kinds of manual valves installed on thermal insulation pipes must not be downward.
2. The valve must be visually inspected before installation, and the nameplate of the valve should comply with the customer’s national standards. For valves with a working pressure greater than 1.0 MPa and acting as a shut-off on the main pipe, strength and tightness performance tests should be carried out before installation, and qualified before use. During the strength test, the test pressure is 1.5 times the nominal pressure, the duration is not less than 5min, and the valve housing and packing should be leak-free. During the tightness test, the test pressure is 1.1 times the nominal pressure; the test pressure lasts no less than 120 seconds during the test, and the valve flap sealing surface is qualified as no leakage.

Tianjin Tanghaidongyang valve Co., Ltd. is one of the largest butterfly valve manufacturers in China, main products are butterfly valves, check valves. Products range: 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 valvegate valvecheck valveglobe valveknife 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

related news /knowledge:
What is butt welding? (6)- Flash butt welding of common metals;
Hard seal installation method of ball valve; 
What is assembly error and how to control it?;
What is machining accuracy, machining error, tolerance?;

The advantages and disadvantages of butterfly valves

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)

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 valvegate valvecheck valveglobe valveknife 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

related news /knowledge: What is the material of the main parts of the butterfly valve?-(2); Characteristics and working principle of electric globe valve; Classification and advantages of gate valve

Installation requirements for manual butterfly valves

1. Before installing the manual butterfly valve, do not throw it away at random. It needs to be placed in a cool, dry and ventilated environment, and it must be covered well to prevent the valve from being contaminated with dust and other debris, which affects the later use.

2. Before installing on the pipeline, the pipeline must be calibrated first. The positions of the pipelines at both ends must be

wafer-type-butterfly-valve-with-handle-13

wafer-type-butterfly-valve-with-handle-13

consistent, and there must be no deviation. Otherwise, if the manual butterfly valve is installed when the pipeline deviates, it will cause tension on the valve body. Or the impact of rupture.

3. In addition to the calibration of the pipeline, there is another preparation before installation, that is, to clean the manual butterfly valve and its pipeline to ensure the cleanness of the valve and the pipeline, otherwise it will affect the sealing effect of the valve.

4. Manual butterfly valves require frequent manual operations. Therefore, the installation position of the manual butterfly valve is also very particular. The valve installation position must be convenient for personnel operation and future maintenance. It has been demonstrated that the best position for manual valve installation is about 1.2 meters on the operating floor. For valves installed outdoors, cover the valve with some covering to prevent the bad weather from affecting the valve.

5. During installation, the butterfly plate of the manual butterfly valve must be in the closed position to avoid collision damage of the butterfly plate and the pipeline flange, affecting the sealing performance.

6. After the installation is completed, commissioning should be carried out. If the manual butterfly valve has an opening and closing failure during use, it is necessary to find out the cause and eliminate the failure. It cannot be forced to open and close by tapping, prying, or brute force.

The installation requirements for manual butterfly valves are actually very simple. We need to pay attention to the details after the valve is purchased. Of course, the key to the safety of the pipeline and the service life of the valve lies in the correct selection and configuration.

Commonly used butterfly valves are wafer-type butterfly valves and flanged butterfly valves. Wafer type butterfly valve is to connect the valve between the two pipeline flanges with double-headed bolts. Flange type butterfly valve is to have a flange on the valve, and use bolts to connect the two ends of the valve to the pipeline flange. There are four types of butterfly valves in Tanghai Valve company, see below:

Butterfly Valve

Tianjin TanghaiDongyang Valve Co., Ltd. is one of the largest butterfly valve manufacturers in China. It was founded in 2006. Its predecessor was Tanghai Valve Manufacturing Factory. 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.

TH Valve is a professional manufacturer of butterfly valvegate valvecheck valveglobe valveknife 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

Related news /knowledge:
Uses and characteristics of manual butterfly valve (4);
Uses and characteristics of manual butterfly valve (3);
Uses and characteristics of manual butterfly valve (2);
What are the main factors affecting valve sealing?