how to test a gas oven safety valve made in china

This website is using a security service to protect itself from online attacks. The action you just performed triggered the security solution. There are several actions that could trigger this block including submitting a certain word or phrase, a SQL command or malformed data.

This website is using a security service to protect itself from online attacks. The action you just performed triggered the security solution. There are several actions that could trigger this block including submitting a certain word or phrase, a SQL command or malformed data.

A60 safety valve is adopted in the European type range. The flameout protection device uses the principle of magnetic attraction of the solenoid valve to ensure that the gas is automatically closed when the flame goes out unexpectedly. Widely used in Europe, Australia, Middle East, Southeast Asia and China market.

A variety of installation ways, the application is more flexibleWe can adjust and tailor-made the specifications according to the structure and functions of the cooker manufacturer. A60 safety valve has a variety of installation methods, including SPIGOT, SADDLE MOUNT, U MOUNT and FLANGE.

The A60 safety valve with CSA, CE and Australian certification meets the highest standards of air tightness, durability and working pressure and temperature in the commercial appliances industry. Cooker"s manufacturers can sell the same model to multiple markets for saving development and design costs.

The body of clamping design of on-off valve A18-X1X can be assembled with a general wrench, which is fast and convenient for assembly. Stainless steel flexible tube are produced from CSA certified raw materials with durable and reliable quality.

Manifolds and gas valves pre-assembly service to save the assembly cost of cooker"s manufacturers and increasing their production capacity. All of Alpha Brass Control"s products are high accurate and 100% air-tight tested.

With the strengthening of China’s environmental awareness and the change of energy structure, China’s urban gas industry has made great progress. The types of gas have developed from simple coal system to multiple gas sources. In the late 1990s, the continuous development, construction and utilization of China’s natural gas resources have promoted the development of China’s urban natural gas into a new era.

The pressure of natural gas transmission and distribution is higher than that of man-made gas, so it is very important to store and transport natural gas safely in densely populated cities and towns. If the leakage and shutdown accidents caused by improper selection or poor quality of

In order to have enough “strength” and “rigidity” — “strength” means that the valve should be able to bear the Zui high pressure of gas transmission and distribution in the pipeline, and more importantly, it must have enough “rigidity”, that is, it can keep the valve from deformation even under various external forces of the underground pipe network, which can guarantee the sealing performance of the valve:

1. Reduce the structural height of the valve as much as possible (referring to the height from the center line of the valve flow section to the valve top) to reduce the buried pipe depth;

2. The top of the valve shall be equipped with a fully closed opening and closing indicator, so that the operator can see the status of the valve at any time, which is an important condition for safe operation;

3. Full diameter design, reduce the flow resistance, facilitate to pass through the pipeline cleaner or pipeline detector, and also meet the requirements of non-stop transmission of closed hole opener to open holes on the pipeline;

4. Reliable sealing performance, cj3055-95 “test and inspection of urban gas valves” standard stipulates that: under 1.1 times of nominal rated service pressure, soft sealing valve is not allowed to have any perceived internal leakage, and under 1.1 times of nominal rated service pressure, hard sealing valve is allowed to have internal leakage less than 0.3dnmm3/s, which is relatively strict, such as: 500mm nominal diameter gas valve The internal leakage per minute shall not be more than 9 ml (the capacity of ordinary drinking cup is 200 ml) and the external leakage is not allowed;

5. The shell of the gas valve used in the underground pipe network shall be corrosion-resistant. It is recommended to use different shell materials according to the transmission medium and service pressure of the pipeline;

6. For the design of valve parts, the structure of less maintenance and no maintenance shall be considered, so as to reduce the workload of maintenance as much as possible, reduce the road closure due to valve maintenance and affect the traffic;

7. Most of the underground pipeline valves are manually opened and closed. It is required that the opening and closing torque of the valve is small, and the number of turns in the whole process should not be too many, and the air source can be cut off as soon as possible after the accident;

8. Various underground pipelines of urban roads in China are crowded and complex, so it is not suitable to excavate basement inspection wells, so direct buried valves are recommended.

1. For the transmission and distribution pipeline under medium pressure class B (0.2MPa), it is recommended to use gray cast iron valve, which has the advantages of good corrosion resistance and low price, so it is very suitable for underground pipeline;

2. For medium pressure class A (0.4MPa) or below, or even high pressure class B (0.8MPa), it is recommended to use ductile iron or cast steel for manufacturing, with emphasis on the selection of ductile iron. For example, compared with cast steel brand WCB, the mechanical property of the former is no less than that of the latter, while the corrosion resistance and casting process are better than that of the cast steel, and the price is also lower than that of the cast steel (generally about 70% of the cast steel). Therefore, the overall performance and price of the ductile iron valve are better than that of the cast steel valve. In the above pressure range, the ductile iron valve can be selected as much as possible, but especially Do not pay attention to the quality control of nodular cast iron;

3. In places with high-pressure class A (1.6Mpa) or higher, it is recommended to select cast steel valves, and WCB brand is generally used to manufacture valves below 4MPa;

PE ball valve has also come out. This series of ball valves can be directly buried and have good sealing performance. However, at present, the price of PE ball valve is relatively high, especially for ball valve larger than 100mm.

In the 1980s, China’s gas is mainly made of artificial coal. There are more impurities and “gas glue” in the artificial coal gas. The traditional single ram wedge type sluice valve can not meet the needs of the gas working condition more and more. This kind of valve generally has the problems of “not tightly closed” and the valve rod is blocked. The gas oil sealed plug valve solves the problems of not tightly closed and the valve rod is blocked. Its main technical features: hard sealing structure is adopted to make it have the function of scraping rubber; the sealing surface does not contact with gas impurities, there is no valve rod in the cavity, and there is no problem of valve rod seizing; the sealing grease and O-ring that are specially developed to resist the erosion of gas medium improve the performance of plug valve.

1. It is not the same diameter as the pipeline, but about 75% of the pipeline flow area, which increases the flow resistance and eddy current, and can not pass through the pig;

With the development of gas industry and the establishment of gas plants, special gas valves with large or even extra large nominal diameter are needed. The problem of artificial gas formation is solved one by one by using parallel double gate valve for gas, and the diameter of Zui is 1600mm.

1. In the process of opening and closing, the parallel double gate valve can scrape off the “gas glue” on the sealing surface, which solves the big problem that the gas impurities adhere to the sealing surface and affect the valve sealing;

V. the valve body adopts the specially designed “squirrel cage frame stiffener” to reduce the overall weight of the valve and enhance the strength and rigidity of the shell;

7. The gate valve of this series is equipped with a fully closed opening and closing indicator, so that the operator can clearly understand the status of the valve.

Compared with the above valves, butterfly valves are lighter, larger in diameter and lower in price. In the early 1980s, some gas companies once used butterfly valves. After about ten years of use, it is generally considered that the effect is not good.

1. The isolation width of the sealing pair of butterfly valve is too narrow, which is easy to cause the valve disc to close excessively or not in place, affecting the sealing;

3. Because the middle part of the seal fitting is rubber or polytetrafluoroethylene, it is easy to be damaged or fall off during gas flushing, and the service life is short. It is proved that butterfly valve is not suitable for gas pipeline except for special position.

Flat gate valve is a general valve which has been used in gas pipeline in recent years. Its flow resistance is small when the valve is full bore, and the seal on both sides is formed by pressing PTFE or rubber O-ring on the gate. This kind of valve can’t be completely closed or fully opened without gas in the middle cavity, which is not convenient for users to judge whether the valve is closed tightly in emergency repair. If the valve is to be completely closed without gas in the middle cavity, the opening and closing torque will increase rapidly; some factories Home made reducer, such as DN200 caliber, with an inner diameter of only 150 mm. Users should pay special attention to it. Therefore, the flat gate valve is suitable for the occasion of lower pressure level system and smaller nominal diameter.

Elastic seal gas gate valve is different from flat gate valve. The features of the valve are similar to the elastic seat structure of the fixed ball valve. The sealing seat rings on both sides of the ram are of the elastic floating structure. The sealing faces are always close together during the opening and closing process, and can compensate the wear of the sealing pair, which is suitable for the occasion of high pressure system. When the valve is fully open and fully closed, there is no gas in the valve cavity, even if the remaining gas in the valve cavity is released There is still no pressure in the cavity, so users can safely construct the pipeline downstream of the valve, which greatly reduces the working time for gas stop preparation before construction.

There are two connection forms of elastic seal gas gate valve: flange type and welding type. Flange type is the traditional connection way. The welding type can directly weld the valve and the pipeline, saving the pipe laying cost; the two kinds of valves can be directly buried, avoiding unnecessary inspection wells, and bringing convenience to the construction.

When the elastic seal gas gate valve is fully opened, it looks like a section of pipeline with the same diameter of the pipeline, with minimal flow resistance; all sealing surfaces are hidden and do not contact with the medium. For the artificial coal to gas, the “gas glue” cannot adhere to the sealing surface, and for the natural gas, the dust and gravel can not wash the parts.

In a word, the elastic sealing gas gate valve is suitable for gas pipeline, especially for underground gas pipeline. From the situation of foreign investigation, many countries use the elastic flat gate valve on the natural gas pipeline. Compared with the nominal diameter elastic flat gate valve and the ball valve, they have the function of fire prevention, and the price is about 30% lower than the ball valve, so the use effect is the same. The disadvantage of Trz series elastic seal gas gate valve is that its structure height is large, and it has 4 nominal diameters. Because it is buried underground, the height above the central axis of the pipeline is the same as that of the common gate valve, and its disadvantage is not obvious, mainly that the height of the lower half is larger than that of the common gate valve, and the buried depth is larger during construction, but generally does not affect the pipeline laying;

The emergency cut-off valve for pressure regulator is an important safety protection device in gas transmission and distribution system. The emergency cut-off valve is to install the emergency trip mechanism on the upper or side position of the stop valve. It is also connected with the regulator body as a whole, and with the filter as a whole. Its function is to shut down the air source in an emergency after the regulator fails, causing overpressure or loss of pressure, so as to ensure safety. The large use of natural gas in the city has improved the pressure level system of the pipe network. The failure of the pressure regulator will bring disastrous consequences to the city. The domestic gas industry has paid more and more attention to this. The products selected in China have not formed a certain trend. Imported, joint venture and domestic products are hard to distinguish between the good and the bad, so the selection should be cautious. RAQ series gas emergency shut-off valve is connected with the filter as a whole, with novel and compact structure and high sensitivity. It can quickly cut off the gas source of the pressure regulator at the set overpressure (300 mm / H2O) and pressure loss (180 mm / H2O) to ensure the safety of users;

In case of gas leakage or other disasters of gas boiler, gas air conditioner and gas equipment, the emergency shut-off valve shall cut off the gas source quickly to prevent the expansion of the disaster. At present, the gas emergency shut-off valve has not been popularized in China. With the strengthening of environmental protection awareness and safety awareness, as well as the development of gas industry, the gas emergency shut-off valve will certainly get people’s attention. The gas emergency shut-off valve is a valve to ensure safety. It is connected with the automatic monitoring equipment to execute the valve closing instruction. Therefore, the gas emergency shut-off valves are all electric valves. According to the existing data, there are two types of such valves, one is solenoid valve, the other is electric valve. Due to the high requirements of gas emergency shut-off valve, such as fast speed, sealing, small flow resistance, caliber specification, etc., the existing solenoid valve and electric valve have certain defects, which can not meet all the requirements. These valves are analyzed one by one as follows:

I. At present, most of the solenoid valves are imported. The speed of the solenoid valve is fast, but the flow resistance is large. The flow resistance Zui in the stop valve is large, the pressure loss is large, and the caliber is small. It is difficult to manufacture the large caliber solenoid valve. Generally, it can only be below DN150, and the price is expensive. If the large caliber solenoid valve is equipped to meet the requirements of the diameter, the technical and economic ratio index is poor. Some solenoid valves are opened by electromagnetic field. Once the power is lost, the valve will be closed even if the power is lost instantaneously, which is not in line with the actual working condition. Uncoupling solenoid valve, energized uncoupling and closing valve, has high sensitivity and fast speed, because with DC low voltage, a little interference or power supply “shaking” will cause misoperation, affecting normal life and production;

2. Electric butterfly valve, with low price, is easy to be made into large caliber, and its opening and closing speed is faster than that of gate valve, and slower than that of solenoid valve; the flow anion is smaller than that of solenoid valve, and larger than that of gate valve; its sealing performance is worse than that of solenoid valve and gate valve, and because of the small sealing isolation width, the rapid opening and closing speed impact is easy to cause insufficient or excessive opening and closing;

3. Electric gate valve, with higher price, small flow resistance and good sealing performance, but its speed is too slow to meet the requirements of emergency cut-off;

4. The ball valve has small flow resistance and good sealing performance. However, the opening and closing speed of domestic or imported electric ball valve in the market is generally within 15-30 seconds, which can not meet the fast requirements. The user’s requirements for the opening and closing speed of emergency shut-off valve are generally within 10 seconds. The electric ball valve has many advantages. It can become an ideal emergency shut-off valve only by improving the opening and closing speed.

The emergency cut-off electric ball valve integrates the advantages of the ball valve, with the opening and closing speed of 3.75 seconds, which fills in the gaps at home and abroad. In addition, it has the function of anti-static and fire prevention in the structure design. The electrical equipment can be connected with the gas leakage alarm, disaster control equipment, fan and other auxiliary equipment. The overall design conforms to the price of dbj08-65-97 technical code for urban natural gas pipeline engineering It is much lower than similar imported products. Once it came out, it was accepted by gas users and received high praise.

The compressor of gas storage and distribution station often needs to be equipped with check valve to prevent gas from flowing back into the compressor. The water check valve has been eliminated in the gas industry. The main disadvantage of the general gas check valve is that the valve plate vibrates with the reciprocating motion of the compressor, which makes a great noise when colliding with the valve body and easily damages the valve plate. The second is poor sealing.

The gas valve plays an important role in the gas industry, and the Ministry of construction attaches great importance to the normative construction of the gas valve. The industry standards of the gas valve include CJ3005-1992 general technical requirements for grey cast iron valves for urban gas, CJ3055-1995 test and inspection for valves for urban gas, CJ3056-1995 general technical regulations for ductile iron and cast steel valves for urban gas In June 2002, it also passed the industry standard of domestic manual gas valve. The formulation and promulgation of these standards standardize the valve industry, promote the progress and development of gas valves, and promote the development of gas industry; provide a reference for the research, production and use units; improve the understanding of the difference between gas valves and general valves, and ensure the safety margin of gas valves; they are welcomed by the gas industry.

1. The underground pipe network is made of medium pressure class B and below, and it is recommended to use direct buried gray cast iron parallel double gate valve;

2. The underground pipe network is of medium pressure class A and below, and it is recommended to use directly buried parallel double gate valve or elastic flat gate valve;

3. For underground pipe network under high pressure class B or under high pressure class A, it is recommended to use directly buried elastic flat gate valve and fixed ball gas ball valve;

5. For storage and distribution station or ground equipment with pressure below 0.4MPa and larger than DN500 caliber, gate valve shall be used as far as possible to reduce the price.

6. In the pressure regulator or pressure regulating station, parallel double gate valve is recommended for low pressure level (below 0.4MPa), and floating type gas ball valve can be used for gas ball valve. If the pressure level system is lower than 1.6Mpa, fixed type gas ball valve and elastic flat gate valve can be used.

7. In the pressure regulating box, if the butterfly valve must be selected due to the limited space conditions, the multi eccentric butterfly valve shall be selected, and the sealing material shall be polytetrafluoroethylene or hard seal, and it must be adjusted to the closed position accurately during commissioning.

China’s gas industry, especially the rapid development and popularization of natural gas, has driven the progress and development of gas valve manufacturing industry. With the introduction of West to east gas transmission, offshore natural gas, and Russian gas sources, new gas valves will come out to meet the needs of gas users.

(Yaang Pipe Industry is a leading manufacturer and supplier of nickel alloy and stainless steel products, including Super Duplex Stainless Steel Flanges, Stainless Steel Flanges, Stainless Steel Pipe Fittings, Stainless Steel Pipe. Yaang products are widely used in Shipbuilding, Nuclear power, Marine engineering, Petroleum, Chemical, Mining, Sewage treatment, Natural gas and Pressure vessels and other industries.)

The gas valve on your boiler controls the flow of gas to the pilot light and burner. When you demand heat or hot water, the boiler works like this: The PCB first detects the fan is operational, ready to expel dangerous flue gases via the flue.

In the open position (gas is flowing) the handle (lever) will be parallel with the pipe, when it is closed (gas not flowing) the handle (lever) will be perpendicular to the pipe. This should make it easy for you to tell if the gas is on, or off.

A thermocouple is a device made of two different metals which creates a small electrical charge when heated at one end by the gas pilot. This small charge causes an electromagnet inside the gas valve to open and allow gas to flow to the main burners.

A gas control valve can be found on any appliance that utilizes gas. These valves are vital for the operation and safety of any gas appliance. The valve does exactly what it sounds like, it controls the amount of gas flowing to create a steady flow without allowing any gas to leak.

Valves for industrial applicationsIn order to prevent the uncontrolled rise in pressure in pressure vessels or pressurized pipelines, a safety valve is inserted. The safety valve is designed so that it opens at a given maximum pressure, thereby relieving the line or the container. Safety valves find their use in almost all areas of the pressure vessel and pipeline construction. In cryogenics as a spring-loaded safety valve for example.

Gases like nitrogen, argon, and hydrogen present unique challenges that demand special gas-handling components. For more than 60 years ZECO has produced standard and custom valves and fittings specifically designed for cryogenic and extreme heat environments. Whether it’s for a compressed gas fill plant, a cryogenic test bench, or any other gas handling application involving extreme temperatures and pressures, count on proven valves to move your gas.

In an effort to finest meet up with client’s requirements, all of our operations are strictly performed in line with our motto “High High quality, Competitive Rate, Fast Service” for High-Pressure Metal Ball Valve, Pneumatic Casting Steel Globe Valve, Pneumatic Forged Steel Globe Valve, Floating Ball Valve, A Gate Valve. We have now deep cooperation with hundreds of factories all over China. The goods we give can match your different calls. Choose us, and we won’t make you regret it! The product will supply to all over the world, such as in Europe, America, Australia, Czech, Armenia, Panama, Netherlands. We will initiate the second phase of our development strategy. Our company regards “reasonable prices, efficient production time and good after-sales service” as our tenet. If you are interested in any of our products or would like to discuss a custom order, please feel free to contact us. We are looking forward to forming successful business relationships with new clients around the world in the near future.

High pressure butterfly valve means the pressure is higher than the PN25 or Class 150Lb butterfly valve. We design and manufacture this kind of valve pressure up to ANSI Class 900# (15.0MPa) maximum. So for a lot of projects, it is a reasonable choice instead of a ball valve and gate valve with much cheaper cost and high performance.

This high pressure butterfly is widely used in foodstuff, beverage, pharmaceutics, boiler, oil refining, chemical machinery industries, chemical, and petrochemical processing, power generating plants, pulp, and paper manufacturing processing, desalination, steelmaking, coal and mining industries

Under normal circumstances, industrial valves are not subjected to strength tests when in use, but the body and bonnet or the valve body and bonnet damaged by corrosion should be tested for strength after repair. For safety valves, the set pressure and return pressure and other tests shall comply with the specifications and relevant regulations. The strength and tightness test of the valve installation should be done. 20% of low-pressure valves should be checked randomly. If they are unqualified, 100% should be checked; medium and high-pressure valves should be 100% checked. Commonly used media for valve pressure testing include water, oil, air, steam, nitrogen, etc. The pressure testing methods for various industrial valves including pneumatic valves are as follows:

Floating ball valve tightness test: put the valve in a half-open state, introduce the test medium at one end, and close the other end; rotate the ball several times, open the closed end when the valve is in the closed state, and check the sealing performance at the packing and gasket at the same time. There must be no leakage. Then introduce the test medium from the other end and repeat the above test.

Trunnion ball valve tightness test: before the test, rotate the sphere without load several times, the fixed ball valve is in the closed state, and the test medium is introduced from one end to the specified value; the pressure gauge is used to check the sealing performance of the inlet end, and the accuracy of the pressure gauge is Level 5 to 1, the range is 1.5 times the test pressure. Within the specified time, there is no decompression phenomenon as qualified; then introduce the test medium from the other end, and repeat the above test. Then, put the valve in a half-open state, with both ends closed, and the inner cavity filled with medium, check the packing and gasket under the test pressure, and there should be no leakage.

Check valve test state: The lift check valve disc axis is in a position perpendicular to the horizontal; the swing check valve channel axis and disc axis are in a position approximately parallel to the horizontal line. In the strength test, the test medium is introduced from the inlet end to the specified value, and the other end is closed. It is qualified if there is no leakage in the valve body and bonnet. In the sealing test, the test medium is introduced from the outlet end, and the sealing surface is checked at the inlet end. No leakage at the packing and gasket is qualified.

The strength test of pressure reducing valve is generally assembled after a single-piece test, and it can also be tested after assembly. The duration of the strength test: 1 min for DN150mm. After the bellows and the components are welded, apply 1.5 times the highest pressure after the pressure-reducing valve, and conduct a strength test with air.

The sealing test shall be carried out according to the actual working medium. When testing with air or water, perform the test at 1.1 times the nominal pressure; when testing with steam, perform the test at the highest working pressure allowed under the working temperature. The difference between the inlet pressure and the outlet pressure must not be less than 0.2MPa. The test method is: after the inlet pressure is adjusted, gradually adjust the adjusting screw of the valve so that the outlet pressure can change sensitively and continuously within the range of the maximum and minimum values, without stagnation or jamming. For the steam pressure-reducing valve, when the inlet pressure is adjusted, the valve is shut off after the valve is closed, and the outlet pressure is the highest and lowest value. Within 2 minutes, the rise in the outlet pressure should meet the requirements in Table 4.176-22. At the same time, the pipeline behind the valve The volume meets the requirements in Table 4.18 as qualified; for water and air pressure-reducing valves, when the inlet pressure is adjusted and the outlet pressure is zero, the pressure reducing valve is closed and the tightness test is performed. No leakage within 2 minutes is qualified.

The strength test of the pneumatic butterfly valve is the same as that of the stop valve. The sealing performance test of the butterfly valve should introduce the test medium from the end of the medium flow, the butterfly plate should be opened, the other end should be closed, and the injection pressure should reach the specified value; after checking the packing and other seals without leakage, close the butterfly plate, open the other end, and check the butterfly No leakage at the plate seal is qualified. The butterfly valve used to adjust the flow can not be tested for sealing performance.

When the plug valve is subjected to a strength test, the medium is introduced from one end, the remaining passages are closed, and the plug is rotated to the fully open working positions for the test. The valve body is qualified without any leakage.

During the sealing test, the straight-through plug should keep the pressure in the cavity equal to that of the passage, rotate the plug to the closed position, check from the other end, and then rotate the plug 180° to repeat the above test; three-way or four-way plug valve The pressure in the cavity and one end of the passage should be kept equal, the stopper should be rotated to the closed position, in turn, the pressure should be introduced from the right-angle end, and the other end should be inspected simultaneously.

Before the plug valve test, it is allowed to apply a layer of non-acidic dilute lubricating oil on the sealing surface, and no leakage or enlarged water droplets within the specified time are qualified. The test time of the plug valve can be shorter, generally 1~3min according to the nominal diameter.

In the diaphragm valve strength test, the medium is introduced from either end, the valve flap is opened, and the other end is closed. After the test pressure rises to the specified value, it is qualified to see if the valve body and bonnet have no leakage. Then reduce the pressure to the tightness test pressure, close the valve flap, and open the other end for inspection. No leakage is considered qualified.

For the strength test of the stop valve and the throttle valve, usually put the assembled valve in the pressure test rack, open the disc, inject the medium to the specified value, and check the valve body and valve Whether the cover is sweating and leaking. The strength test can also be performed on a single piece. Only stop valves are used for the sealing tests. During the test, the valve stem of the shut-off valve is in a vertical state, the valve flap is opened, and the medium is introduced from the bottom end of the valve flap to the specified value. Check the packing and gasket; close the valve flap after passing the test, and open the other end to check for leakage. If both the valve strength and tightness tests are to be done, the strength test can be done first, then the pressure is reduced to the specified value of the tightness test, and the packing and gaskets are checked; then the valve flap is closed and the outlet end is opened to check whether the sealing surface is leaking.

Open the gate to increase the pressure in the valve to the specified value; then close the gate and immediately take out the gate valve to check whether there is any leakage at the seals on both sides of the gate or directly inject the test medium into the plug on the valve cover to the specified value, Check the seals on both sides of the gate. The above method is called the intermediate pressure test. This method is not suitable for sealing tests on gate valves with a nominal diameter below DN32mm.

Another method is to open the gate to increase the test pressure of the valve to the specified value; then close the gate and open the blind plate at one end to check whether the sealing surface is leaking. It fell further, to make the above test repeated engagement until the grid.

The strength test of the safety valve is the same as that of other valves. It is tested with water. When testing the lower part of the valve body, the pressure is introduced from the inlet I=I end and the sealing surface is closed; when testing the upper part of the valve body and the bonnet, the pressure is introduced from the outlet El end and the other ends are closed. No leakage of the valve body and bonnet within the specified time is qualified.

For the sealing test and constant pressure test, the general use medium is: steam safety valve uses saturated steam as the test medium; ammonia or other gas valves use air as the test medium; water and other non-corrosive liquid valves use water as the test medium. For safety valves in some important positions, nitrogen is often used as the test medium.

The sealing test shall be conducted with the nominal pressure value as the test pressure, the number of times shall not be less than twice, and no leakage within the specified time shall be qualified. There are two leak detection methods: one is to seal the joints of the safety valve and use butter to seal the thin paper on the flange of the outlet. The plastic plate or other plate seal is attached to the lower part of the outlet flange, and the valve disc is sealed with water. It is qualified if the water does not bubble. The safety valve’s constant pressure and return pressure test times are not less than 3 times, and it is qualified as conforming to the regulations. The various performance tests of safety valves refer to GB/T 12242-1989 Safety Valve Performance Test Methods.

After unpacking all valves should be visually inspected, comprising a plate on the valve body is complete, the product quality documents, the valve is closed, the other can not damage the like blue surface, no Dirty, both ends of the anti-protection Cover, etc.

The valve pressure test JHA is perfect, and the operator should be familiar with the safety hazards of the valve pressure test and reverse transportation and take corresponding preventive measures.

The valve pressure test process is the valve shell strength test, upper seal test, and seal test.The test medium for the strength of the valve shell is water, the pressure is 1.5 times the nominal pressure of the valve, the pressure holding time is 5 minutes, and no drip or moisture is qualified.

The sealing test medium on the valve adopts water, the pressure is 1.5 times the nominal pressure, the holding time is 15s for DN≤50, the 60s for 65≤DN≤300, and the 120s for DN≥350. No leakage is qualified.

Valve sealing test: Low-pressure sealing test is carried out. The test medium is air (gate valve), the pressure is 0.6MPa, the pressure holding time is 15s for DN≤50, the 60s for 65≤DN≤150, and the 120s for DN≧200. The requirement is qualified.

After the pressure test, the valves should be stacked separately according to the type and specifications of the device, and the unqualified products should be stacked separately; each stacking area should be erected with a clear sign. After the pressure test, the valve should be closed and sealed, and covered and protected with colored cloth in the stacking area.

After the valve pressure test, the “Valve/Pipe Fitting Test Record” should be filled in time according to the device, and the model column should be filled in with the purchase contract number on the valve body.

TitleGB/T 7742.2-2015: Translated English of Chinese Standard. (GBT 7742.2-2015, GB/T7742.2-2015, GBT7742.2-2015): Textiles - Bursting properties of fabrics - Part 2: Pneumatic method for determination of bursting strength and bursting distension

This Standard specifies the terms and definitions, basic structural style and model, technical requirements, test methods, inspection rules, marking, packaging, transportation, and storage of gas cylinder valve for air rebreather.

A gas stove is a stove that is fuelled by combustible gas such as syngas, natural gas, propane, butane, liquefied petroleum gas or other flammable gas. Before the advent of gas, cooking stoves relied on solid fuels such as coal or wood. The first gas stoves were developed in the 1820s and a gas stove factory was established in England in 1836. This new cooking technology had the advantage of being easily adjustable and could be turned off when not in use. The gas stove, however, did not become a commercial success until the 1880s, by which time supplies of piped gas were available in cities and large towns in Britain. The stoves became widespread on the European Continent and in the United States in the early 20th century.

Gas stoves became more common when the oven was integrated into the base and the size was reduced to better fit in with the rest of the kitchen furniture. By the 1910s, producers started to enamel their gas stoves for easier cleaning. Ignition of the gas was originally by match and this was followed by the more convenient pilot light. This had the disadvantage of continually consuming gas. The oven still needed to be lit by match and accidentally turning on the gas without igniting it could lead to an explosion. To prevent these types of accidents, oven manufacturers developed and installed a safety valve called a flame failure device for gas hobs (cooktops) and ovens. Most modern gas stoves have electronic ignition, automatic timers for the oven and extractor hoods to remove fumes.

Gas stoves are a significant source of indoor air pollution,methane emissions from gas stoves in the United States were equivalent to the greenhouse gas emissions of 500,000 cars.gas venting and unintended fugitive emissions throughout the supply chain results in natural gas having a similar carbon footprint to other fossil fuels overall.

The first gas stove was developed in 1802 by Zachäus Winzler (de), but this along with other attempts remained isolated experiments.Northampton, England in 1826 and opened a gas stove factory in 1836. His invention was marketed by the firm Smith & Philips from 1828. An important figure in the early acceptance of this new technology, was Alexis Soyer, the renowned chef at the Reform Club in London. From 1841, he converted his kitchen to consume piped gas, arguing that gas was cheaper overall because the supply could be turned off when the stove was not in use.

A gas stove was shown at the Great Exhibition in London in 1851, but it was only in the 1880s that the technology became a commercial success in England. By that stage a large and reliable network for gas pipeline transport had spread over much of the country, making gas relatively cheap and efficient for domestic use. Gas stoves only became widespread on the European Continent and in the United States in the early 20th century.

Early gas stoves were rather unwieldy, but soon the oven was integrated into the base and the size was reduced to fit in better with the rest of the kitchen furniture.

Gas stoves today use two basic types of ignition sources, standing pilot and electric.pilot light) under the cooktop.flame failure device for gas hobs (cooktops) and ovens. The safety valve depends on a thermocouple that sends a signal to the valve to stay open. Although most modern gas stoves have electronic ignition, many households have gas cooking ranges and ovens that need to be lit with a flame. Electric ignition stoves use electric sparks to ignite the surface burners.Auto reignition is an elegant refinement: the user need not know or understand the wait-then-turn sequence. They simply turn the burner knob to the desired flame size and the sparking is turned off automatically when the flame lights. Auto reignition also provides a safety feature: the flame will be automatically reignited if the flame goes out while the gas is still on—for example by a gust of wind. If the power fails, surface burners must be manually match-lit.

Also stoves with electric ignition must be connected with gas protection mechanisms such as gas control breaker. Because of this many manufacturers supply stoves without electricity plug.

One of the important properties of a gas stove is the heat emitted by the burners. Burner heat is typically specified in terms of kilowatts or British Thermal Units per hour and is directly based on the gas consumption rather than heat absorbed by pans.

Often, a gas stove will have burners with different heat output ratings. For example, a gas cooktop may have a high output burner, often in the range 3 to 6 kilowatts (10,000 to 20,000 BTU/h), and a mixture of medium output burners, 1.5 to 3 kW, and low output burners, 1 kW or less. The high output burner is suitable for boiling a large pot of water quickly, sautéing and searing, while the low output burners are good for simmering.

Some high-end cooktop models provide higher range of heat and heavy-duty burners that can go up to 6 kilowatts (20,000 BTU/h) or even more. These may be desired for preparing large quantities or special types of food and enable certain advanced cooking techniques. However, these burners produce greater emissions and necessitate better ventilation for safe operation.

In the last few years, appliance manufacturers have been making innovative changes to the design and layout of gas stoves. Most of the modern cooktops have come with lattice structure which usually covers the complete range of the top, enabling sliding of cookware from one burner to another without lifting the containers over the gaps of cooktop. Some modern gas stoves also have central fifth burner or an integrated griddle in between the outer burners.

Usually, there isn"t much of a style difference in between them. Slide-in come with lips on their either side and controls over the front along with burner controls. Freestanding gas range cooktops have solid slides and controls placed behind the cooktop.

Many stoves have integrated ovens. Modern ovens often include a convection fan inside the oven to provide even air circulation and let the food cook evenly. Some modern ovens come with temperature sensors which allows close control of baking, automatically shut off after reaching certain temperature, or hold on to particular temperature through the cooking process. Ovens may also have two separate oven bays which allows cooking of two different dishes at the same time.

Many gas stoves come with at least few modern programmable controls to make the handling easier. LCD displays and some other complex cooking routines are some of the standard features present in most of the basic and high-end manufacturing models. Some of the other programmable controls include precise pre-heating, automatic pizza, cook timers and others.

A built-in Japanese three burner gas stove with a fish grill. Note the thermistor buttons protruding from the gas burners, which cut off the flame if the temperature exceeds 250°C.

Modern gas stove ranges are safer than older models. Two of the major safety concerns with gas stoves are child-safe controls and accidental ignition. Some gas cooktops have knobs which can be accidentally switched on even with a gentle bump.

Gas stoves are at risk of overheating when frying oil, raising the oil temperature to the auto-ignition point and creating an oil fire on the stove. Japan, South Korea and China have regulated the addition of electronic safety devices to prevent pan overheating. The devices use a thermistor to monitor the temperature close to the pan, and cut off the gas supply if the heat is too high.

The U.S. Department of Energy (DOE) ran tests in 2014 of cooktop energy transfer efficiency, simulating cooking while testing what percentage of a cooktop"s energy is transferred to a test block. Gas had an efficiency of 43.9%, with ±0.5% repeatability in the measurement. This level of efficiency is only possible if the pan is big enough for the burner.

Japanese gas flames are angled upwards towards the pot to increase efficiency.heatsink-like fins.Jetboil manufactures pots for portable stoves that use a corrugated ribbon to increase efficiency.

Carbon monoxide, formaldehyde, and nitrogen dioxide from gas stoves contribute to indoor air pollution.asthma.The Lancet Respiratory Medicine found that evidence was conflicting on an association between gas cooking and asthma.

Cooking, especially high heat frying, releases smoke (measured as fine particulate matter), acrolein and polycyclic aromatic hydrocarbons.air purifier.U.S. Consumer Product Safety Commission is investigating reducing the health effects of gas stoves, including emissions and ventilation standards.

Gas stoves are often run on natural gas. The extraction and consumption of natural gas is a major and growing contributor to climate change.methane) and carbon dioxide, which is released when natural gas is burned, are greenhouse gases.methane emissions from gas stoves in the United States were equivalent to the greenhouse gas emissions of 500,000 cars.

Some places, such as the Australian Capital Territory, have curtailed installation of gas stoves and appliances in new construction, for reasons of health, indoor air quality, and climate protection.

Because of different of drive source, SSV can dividedinto Hydraulic safety valve and pneumatic valve ; With thermal and high voltage explosion-proof device ; Actuators and prepare two parts of the valve, standard interface, easy replacement and maintenance .

This valve is used for power plant boilers, pressure containers, pressure and temperature reducing device and other facilities. It serves to prevent the pressure exceeding the highest allowable pres-sure value and ensure the safety of the device when working.

（1）The pressure of the disc is balanced through the lever and heavy hammer and the valve is ensured seal by moving the for ton of heavy hammer and changing the weight of heavy hammer to reach the required set pressure.

（2）The sealed surface is made of Fe base stainless steel by overlaying welding. Through thermal treatment, the wear resistance and anti-erosion of disc is improved.

（3）At the top of valve is equipped an electromagnet to open and another to close the valve. The actions of the mechanism and the electric appliance are separate and will not affect each other.

（2）Impulse safety valve shall be installed vertically and the lever shall be kept level. The clearance from the lever to both sides of guide fork shall be even.

（4）A long distance between the leading pipe of the impulse safety valve and the inlet pipe of the main safety valve shall be kept. And the distance between the electric contact pressure meter and the inlet pipe of the main safety valve shall be no less than 5 times of the diameter of the inlet pipe, for feat that the validity of the mater and the impulse safety valve may be affected by the steam releasing process of the main safety valve.

This valve is used for power plant boilers, pressure containers, pressure and temperature reducing device and other facilities. It serves to present the pressure exceeding the highest allowable pres-sure value and ensure the safety of the device when working.

1,When the medium pressure rises to the set pressure, the in-pulse safety valve opens, and the medium in the impulse pipe enters into the piston chamber of the main safety valve from impulse pipe, forcing the piston to descend, and then the valve automatically open-s; when the impulse safety valve closes, the disc will slash automatically close.

2,The sealed surface is made of Fe base stainless steel by over-laying welding. Through thermal treatment, the wear resistance and anti-erosion of disc so improved.

2,The main safety valve shall be fastened upon the gallows, which sustains the back-seat force produced in the steam discharging process of the main safety valve.

3,The exhaust pipe shall contain a special gallows to prevent the force of its weight directly applying on the main safety valve. The connecting Lange At the lowest point of the exhaust pipe, water drainage shall be taken into consideration to avoid producing water hammer while discharging set between the main safety valve and exhaust pipe shall eliminate any extra stress.

A self-regulated control valve is used for adjusting the flow by using fluid pressure in the pipe. The flow is adjusted by receiving the energy from the controlled system. It has a simple structure and is economical to use.

The self-regulated valves that control the pressure at its inlet are called self-actuated upstream pressure control valves. They control the pressure at its outlet are known as self-actuated downstream pressure control valves.

The self-regulated control valve is the pressure-reducing valve and maintains stable secondary pressure without disturbing the primary pressure. The self-regulated pressure valve does not depend on the external signal for controlling pressure; instead, the pressure itself acts as a signal for opening or closing the pressure valve.

A self-regulated control valve controls the pressure at the upstream or downstream side of the control valve. If the pressure upstream is used to accelerate the control valve, the upstream pressure is maintained at a specific set point called the backpressure control valve. This valve is responsible for maintaining the back pressure by the control valve.

If the downstream pressure valve throttles the control valve, then the downstream pressure is maintained at a specific set point called self-regulated control valves.

The self-regulated control valve is applicable in various throttling applications and on/off applications. The process fluid is put into the diaphragm or piston, passing through the pilot to maintain the pressure. The pilot controls the main valve’s motion of the system. The pressure control requires three functional units, the controller, the measuring equipment, and the final controlling equipment.

The self-regulated control valveis expensive and complex in differential pressure or temperature control tasks. With less downstream pressure, the more trim open, and more downstream pressure causes more trim closing. The spring has the setpoint valve, which can be replaced if a different setpoint is required.

There is a pilot-loaded pressure regulator that uses external gas pressure for getting the pressure regulation set point. The pressure regulator acts as a pilot device to load pressure into the primary.

Regulator’s actuating diaphragm. The external load pressure establishes the regulator’s setpoint instead of the internal spring of the self-regulated control valve.

You can smoothly adjust the pressure by turning the knob on the pressure regulator, which is also adjustable at this point. The function of the pilot mechanism is to control the primary gas throttling mechanism. The pilot-operated valve is used in liquid service rather than gas.

This self-regulated control valve has a forged valve body. It has a nominal pressure of 6.4Mpa, 10Mpa, and 16Mpa and is suitable for high-pressure applications. The high-pressure self-actuated pressure reducing valve has two types, upstream and downstream self-regulating pressure reducing valve.

The downstream pressure makes sure to keep pressure behind the valve constant. It is suitable for oil, water, and non-corrosive gas at a temperature below 350°C.

It has two main parts, the temperature sensor, and globe valve. It uses the principle of liquid thermal expansion to control pressure. It has a temperature range from -20°C-350°C. The self-operated temperature control valve is categorized into heating type, cooling type, and mixing type.

With the temperature rise, the valve closes that reduces the flow rate. Whenever the temperature decreases below the set value, it increases the flow rate of the medium to increase the temperature.

The self-operated micro pressure regulator is divided into a single seat and a double seat. It does not need any external energy, and the actuator controls the position of the spool. The actuator changes the pressure difference and flow and achieves pressure stability and relief for downstream and upstream types.

The self-regulated control valve consists of a pilot tube that takes the process fluid to pressurize the diaphragm. The diaphragm opens the valve so that the process fluid can pass through. The pilot tube connects the diaphragm to the downstream of the control valve. When the downstream pressure increases in the self-regulated control valve, the pressure is exerted on the diaphragm and closed.

When the valve closes, the process fluid also stops, reducing the downstream pressure to the setpoint level. When it’s below the set point, the liquid from the diaphragm goes back to the process line, thus relieving the pressure on the diaphragm. However, it results in the valve opening, increasing the process flow, thus increasing the pressure to its set point.

In the backpressure regulator valve, the diaphragm connects with the upstream of the pressure control valve. The process fluid is responsible for the opening and closing of the valve due to high or low pressure.

The self-regulated control valve is suitable for pressure, temperature, and differential pressure control in various applications. It is used in applications where there is the deviation of controlled variables from the given set point. These setpoints are usually constant for the entire equipment life. The self-regulated control valve needs auxiliary power to operate the electrical signal. It has an actuator that connects to the valve.

The self-regulated control valve is used widely in gas, clean water, and heat supplier applications. It is a very reliable tool in providing control functions. Even in applications with energy supply failure, the self-regulated control valve is ideal as safety equipment. These valves maintain the inlet and outlet pressure in hygienic applications for dairy, food, and beverage industries.

The self-regulated control valve consists of a control valve, actuator, and a spring for pressure control. It is used for controlling the downstream pressure in the pipes. The control valve is closed when the downstream pressure arises. Some of the features of a self-regulated control valve are as follows: It provides upstream and downstream pressure control of non-corrosive liquids and gases.

It is cost-effective as a self-regulated control valve does not require energy sources. Therefore, there is no need for electricity or gas sources to run it.

8.What are the technical specifications of the self-regulated control valve? The range of low pressure reducing valves for pressure setpoints ranges from 0.075 to 0.75 psi.

The bellow actuator has a set point ranges from 75 to 145, 145 to 320, 290 to 400 psi. The bellow actuator housing has the material of AISI 304, AISI 316Ti.

The medium flows through the valve, and the flow rate is determined by the position of the valve plug and the free area between the plug and seat. The plug stem is connected to the stem of the actuator. For controlling pressure, the diaphragm is joined by the positioning springs and the adjustment nut. The self-regulated control valve is opened by the positioning spring once both the pressures are balanced.

The downstream pressure P² is controlled downstream of the valve. It is transmitted to the operating diaphragm through the control line, changing it into the positioning force. This force adjusts the valve plug and is adjustable at the set point adjustment nut. When the downstream pressure P² rises above the setpoint, the valve closes, and pressure changes.

The valves have the balancing bellows where the downstream pressure acts on the inner surface of bellows, while the upstream pressure works on the outer bellow surface. Thus, it balances the forces produced by the upstream and downstream pressure.

In letdown pressure regulators, no power supply is required, and the failure position is the position it takes if any of the components fail. If the diaphragm or downstream pressure breaks, the regulator opens. The regulator closes when the spring breaks. For overcoming the diaphragm failure, you need to place a relief valve.

Cavitation occurs between the two valves when the pressure inside the valve drops below the vapor pressure of the flowing fluid. It can be overcome with the pressure recovery coefficients of the regulators and cavitation coefficients.

For testing the proper functioning of the self-regulated control valve, you need to have a regulator and test gauge. First, check the instrument data and pressure requirement. Check the specification sheet of the vendor and the maximum allowable pressure. Open valve A and check the pressure indication on test gauge B with the set pressure.

If the set pressure does not meet the specifications, you need to remove the setpoint adjustment screws of the self-regulated control valve. Adjust the screw until the desired pressure is achieved. This procedure is used for pressure reduction in the control valve.

The second method is the backpressure regulator method, in which the regulator and test gauge are needed as the testing equipment. In this method, you first need to check the instrument data and vendor’s specification sheet. The instrument is set up for testing.

Repeat the same procedure by opening valve A and note down the pressure indication of valve B as the set pressure. If the set pressure is not per the specifications, remove the set point adjustment screw and adjust it until the test gauge reaches the desired pressure.

The self-regulated control valves are used to control and maintain pressure in various applications. The self-regulated control valves are standard in the gas industry, while the pilot regulated control valve is suitable in high flow situations. The self-regulated control valve consists of three main parts: A measuring element

The loading element is weight, spring, or pressure from some external source. When you compress the spring, it produces a loading force. The diaphragm connects to the process fluid, which creates a force against the loading force.

The restrictive element is connected to the spring. The diaphragm regulates the flow through the regulator. In the self-regulated control valve, the downstream pressure decreases the spring force. This force overcomes the gas on the diaphragm causing the valve to open and increase the flow. The increase in pressure closes the valve and reduces the flow.

The self-regulated control valve is a cost-effective and optimized pressure measuring solution used in various distribution networks. The tricky task is to purchase a suitable self-regulated control valve for your application. When there are changes in the physical environment of the valve, the self-regulated control valve responds by opening or closing.

A differential pressure regulator applies the pressure of the fluid against the diaphragm. The diaphragm uses a spring to get force balance with the diaphragm at the set pressure. You need to maintain higher differentials between temperature and flow in heating systems to get the most out of energy.

If you want to achieve the high efficiency of the self-regulated control valve, the balanced flow control system is preferred, ensuring a balanced supply of heating and cooling in all installation parts. In addition, the control valves use downstream to maintain accurate performance.

The pressure-independent control valves are successful in providing cost-effective control within the distribution networks. Another important factor is considering the low supply and centralized distribution factors for getting the balanced heating system. The self-regulated control valve is the self-controlling valve that does not need any further input. Therefore, it provides the best performance and proper levels.

14.What are the safety precautions of using a self-regulated control valve? Some preventive measures need to keep in mind while you are operating a self-regulated control valve. Some safety precautions are as follows:

It is recommended to avoid connecting the valves and regulators to the supply source, which has a higher pressure than the regulator’s maximum rated pressure.

Read the product label specifications carefully. If there is no rate pressure, contact your representative for the rated pressure installation and use.

Before the installation of regulators and valves, establish the flow direction of the fluid. It is the primary duty of the user to install the equipment properly.

Self-regulated temperature control valves do not depend on external power sources to regulate the temperature in various systems. For example, these are commonly used for boiler temperature adjustment by maintaining a linear relationship between temperature and the valve.

For operating the self-regulated temperature control valve, the sensor is inserted into the pipeline—the change in temperature results in the opening of the valve. If the temperature rises, the sensor is heated and expands capillary to close the valve.

Once the temperature changes, the liquid volume changes. This change is transmitted through the capillary tube while the actuator acts on the valve stem. When the temperature is heated, it will close the valve. When the temperature is cooled, it opens the valve.

There are some techniques and strategies for installing the self-regulated control valve. While installing, make sure that the valve body is installed at the inlet of the primary heat mediu