LSH vertical horizontal water pipe coal-fired steam boiler

1、 Structure Introduction
The LSH type vertical horizontal water tube coal-fired steam boiler adopts traditional combustion technology. Coal is input from the furnace door and burned on the grate, and the flue gas is flushed through the horizontal water tube in a staggered manner inside the furnace The fine carbon black and dust contained in the flue gas are cut by multiple layers of tube bundles and fall onto the grate for re combustion, and then discharged into the atmosphere through the chimney.
2、 Boiler characteristics
1. Boiler characteristics
(1) Compact structure, easy installation and migration, small footprint, and low infrastructure investment.
(2) The longitudinal flushing of the flue gas convection tube bundle fully utilizes the heating surface to improve boiler efficiency.
(3) Due to the multiple return and circulation of flue gas, natural dust removal is achieved.
Installation instructions
3、 Pre installation preparation
After the boiler is transported to the site, for the sake of speed, the following work must be done before installation:
1. Organization and staffing:
Boiler installation must be carried out by a dedicated person, with the participation of the boiler operator, and equipped with plumbers, fitters, lifting workers, cold workers, welders, and auxiliary workers
2. Study relevant materials carefully:
Relevant personnel should carefully study the "Safety Technical Supervision Regulations for Steam Boilers" (96), boiler drawings, installation and use instructions, and other technical documents to understand and master matters such as installation, lifting, and operation.
3. Determine installation location:
(1) It is best to choose an installation location close to the gas consumption point, in order to shorten the pipeline, reduce infrastructure costs, and minimize heat dissipation losses.
(2) Convenient water supply and drainage.
(3) The storage and transportation of fuel and ash are convenient.
(4) The boiler should be installed and transported smoothly
(5) The layout of the boiler room should comply with the provisions of Chapter 8 of the "Steam Boiler Safety Technical Supervision Regulations" (96) of the Ministry of Labor. The lighting should be sufficient, the ventilation should be good, and there should be no water accumulation on the ground. To ensure convenient operation and maintenance, there should be a gap of 3 meters in front of the boiler, 2.5-3 meters behind the boiler, and no less than 1 meter on both sides.
(6) It is strictly prohibited to stack toxic and flammable materials in the boiler room.
(7) The door from the boiler room to the outside should open outward, and the windows of the lounge should also open outward.
4. Basic preparation:
Construct the foundation according to the foundation map, and the thickness of the concrete can be determined based on the geological conditions. When mixing, the proportion of sand and gravel concrete should be appropriate.
4、 Installation of large boiler components
1. Boiler equipment acceptance:
(1) After the boiler is transported, the components are counted according to the manufacturer's factory list, and the integrity of the equipment is checked based on the boiler drawings and technical documents. Check if there is any damage or deformation to the large components of the boiler during transportation.
(2) When unloading large boiler components, one end of the base can be tied with steel wire ropes on both sides, and one end of the boiler shell head can be threaded with a lifting ear into another steel wire rope to find the lifting center and slowly lift the boiler. The lifting equipment has a capacity of not less than 10 tons. After the boiler leaves the vehicle, it should be placed on a wide horizontal surface first, and the bottom of the boiler should be supported by brackets to avoid damaging the pipe seat, etc.
(3) When the boiler is in place, it must be in an upright position. When standing upright, lifting equipment should be used to grab the top lifting ears of the boiler, and no other parts should be tied.
(4) After the boiler is in place, it should be kept horizontal in the front, back, left, and right directions, with an allowable inclination of not less than 5mm. Otherwise, the lower parts should be raised with shims.
(5) There should be no large gap between the boiler and the foundation, and it is required to be tight without air leakage. Cement should be used to fill the gaps where there are gaps.
5、 Installation of chimney and smoke control door
When installing chimneys and smoke control doors, asbestos ropes should be embedded between the flanges, and the inclination of the chimney should be checked using a plumb line. If there is any deviation, a flat iron wire rope can be placed at the flange connection and tightened with a blue bolt. Note that the tension of the three iron wires should be roughly equal. The smoke control door should rotate flexibly, and the zipper of the locator should not be too high.
6、 Installation of electrical control cabinet
The electrical control cabinet gathers all the switch buttons of the electric motors on the boiler. Users can first connect the wires to each motor, and then connect the external power supply. The box shell should be grounded. The electrical control cabinet should be installed in front of the boiler, close to the wall, to facilitate monitoring of various power meters on the boiler and maintain easy operation.
7、 Installation of pipelines, valves, instruments, and accessories
1. Install the boiler according to the pipeline, valve, and instrument diagram. After pouring the foundation of the electric pump, connect the power supply and test run it.
2. The safety valve should be installed after the hydrostatic test. The safety valve should be connected to the exhaust pipe to direct the exhaust steam to a safe location outside the boiler room. The safety valve should be installed vertically. The safety valve should be pressure adjusted as required.
3. The sewage pipe should be connected to the sewage tank or other safe place, and the pipeline should be fixed to prevent accidents such as burns during sewage discharge.
4. The steam pipes outside the main valve shall be connected by the user unit, and there shall be at least one elbow on the main valve pipeline. Otherwise, expansion pipes shall be installed, and the outer wall of the pipeline shall be insulated.
5. The lower drainage pipe of the water level gauge must be connected to a safe location, and the steam water connection valve between the water level gauge and the boiler must rotate flexibly without leakage. Lighting equipment must be installed at the water level gauge for easy observation.
6. After the pressure gauge is installed, a red line should be drawn on the dial to indicate the maximum allowable working pressure of the boiler. The three-way plug of the pressure gauge should work flexibly and not leak water. The drainage should be unobstructed, and the pressure gauge tube should not be insulated.
7. It is strictly prohibited to use a pressure gauge in any of the following situations:
(1) The pressure gauge with a limited stop pin cannot return to the limit pin after the pointer rotates when there is no pressure; A pressure gauge without a limiting pin may have a pointer above zero when there is no pressure, exceeding the allowable deviation specified by the pressure gauge.
(2) The glass surface is broken or the dial scale is unclear.
(3) Seal damage or exceeding inspection period.
(4) Surface leakage or pointer jumping.
Instructions for Use
8、 Inspection before baking and boiling
Before baking and boiling, it is necessary to carefully inspect all components of the boiler, and the inspection items are as follows:
1. Whether the manhole and handhole are tight, and whether the accessory parts and devices are complete.
2. Whether the steam pipeline, water supply pipeline, and sewage pipeline are complete.
3. Is the smoke passage unobstructed.
9、 Boiling furnace
After the installation, inspection, and trial operation of all components of the boiler, it can be confirmed that they meet the safe start-up conditions before starting the boiler.
1. During boiling, appropriate chemicals need to be added to the boiler to make the boiler water alkaline and remove impurities such as oil stains.
2. Boiling can use drugs such as sodium hydroxide (NaOH) or trisodium phosphate (Na3PO4.12HO), and the dosage is calculated based on the boiler volume per cubic meter of water. Use 2-3 kilograms of medicine per cubic meter. The above-mentioned drugs used for boiling should be prepared as a uniform solution with a concentration of 20%, and solid drugs should not be directly added to the boiler. The above-mentioned drugs used for boiling should be prepared as a uniform solution with a concentration of 20%, and solid drugs should not be directly added to the boiler.
3. Close all pipe sockets and hand holes, main steam valve seat and water level gauge drain valve, open the manhole, pour the prepared drug solution into the drum at once, then close the manhole and open the safety valve; Provide a channel for the air and steam inside the furnace to be discharged outward.
4. Inject the treated water into the boiler, with the inlet water temperature generally not exceeding 40 ℃. The water level in the drum should reach 2/3 of the water level gauge. Close the water supply valve and wait for the water level in the boiler to stabilize. Observe whether the water level has decreased and check whether there is any leakage in the manhole cover, handhole cover, flange joint surface, and drain valve of the boiler. If there is any leakage, tighten the bolts.
5. Open the ignition door: Lay a layer of 100-200mm thick coal slag on the entire range of the grate end face, and ignite it with firewood (strictly prohibited to use wooden boards with iron nails), oil wool yarn or other ignition materials on the coal slag.
6. The firewood should be gradually strengthened to avoid sudden heating. During this time, open the smoke control door and use natural ventilation. The pressure in the pot should not be maintained frequently. If the pressure rises to 0.1 megapascal (1 atmosphere) or above, the exhaust valve should be immediately opened to release steam. If the water level drops, water should be immediately introduced.
7. When the boiler pressure gradually rises to below 0.2 megapascals (2 atmospheres) and the water temperature drops below 70 ℃, open the drain valve and release all the sewage.
10、 Raise the fire
1. Before starting the boiler, a comprehensive inspection (including relevant accessories and pipelines) should be conducted before carrying out the water supply work. Before water enters, the drain valve must be closed and the main steam valve must be opened to allow the air in the boiler to be discharged.
2. Slowly inject the treated water into the furnace, with the inlet water temperature generally not exceeding 40 ℃
When the water level reaches the lowest level on the water level gauge, close the water supply valve and wait for the water level in the pot to stabilize before observing whether the water level has decreased.
3. When starting the fire, open the ignition door and place wood and other igniters on the grate (iron nails are strictly prohibited) to ignite. After the igniters are burned, adjust the flue gas control valve to a smaller size. After the igniters are burned vigorously, start to manually add coal. When the coal seam is burned vigorously, continue to add coal. Strengthen the observation of the fire situation, and properly switch the fire. The furnace negative pressure is maintained at 19.6-29.4 Pa (2-3 mm water column) to make the combustion gradually normal.
4. The temperature should not increase too quickly during ignition to avoid excessive thermal stress caused by different heating conditions in various parts, which may affect the service life of the boiler. The time from the cold furnace to the pressure rise to the working pressure during the initial ignition should be 3-4 hours. In the future, unless there are special circumstances that require urgent use of steam, the cold furnace should not be less than 3 hours, and the hot furnace should not be less than 1 hour.
5. After raising the heat, always pay attention to the water level in the pot, as the water level will rise after heating. If it exceeds the water level gauge, it can be drained.
6. When steam is emitted from the opened safety valve, the safety valve should be closed and the pressure gauge bend and water level gauge should be flushed. When the air pressure rises to 0.1 megapascal (1 atmosphere), check whether the manhole and handhole cover are leaking. If there is any leakage, tighten the manhole and handhole cover bolts, and check whether the drain valve is tight and leak free.
7. When the pressure inside the boiler gradually increases, attention should be paid to whether there are any special noises from various parts of the boiler. If there are, they should be checked immediately. If necessary, the boiler should be stopped immediately for inspection. Only after the fault is resolved can it continue to operate.
11、 Supply of steam
When the pressure inside the boiler approaches the working pressure, prepare to supply steam to the outside. Before supplying steam, the water level inside the boiler should not exceed the normal water level, and the combustion inside the furnace should be stable during steam supply.
When supplying steam, the main steam valve should be slightly opened to allow a small amount of steam to warm up the pipe. At the same time, the drain valve on the pipeline should be opened to release condensed water. The heating time is determined by the length, diameter, steam temperature, and other factors of the pipeline. Generally, it should not be less than 10 minutes. When warming up the pipes, attention should be paid to the expansion of the pipes and the condition of the pipe supports. If any abnormal conditions are found, the heating of the pipes should be stopped, and the faults and defects should be eliminated. After the pipes have heated up and the condensed water in the pipes has gradually decreased, the main steam valve can be fully opened. It is advisable to start slowly, and at the same time, pay attention to whether there are any special conditions in the boiler components. If there are any, they should be checked immediately. If necessary, the boiler should be stopped for inspection. After the main valve is fully opened, the main valve wheel should be returned half a turn to prevent defects such as inability to rotate due to thermal expansion. After the boiler is supplied with steam, the accessory parts, valves, and instruments should be inspected again for any leaks and whether they are working properly. To prevent the water level from flooding the glass tube under any circumstances due to hanging water (steam carrying water), the main steam valve should not be opened too much, generally controlled between 1-2. Under normal combustion conditions, the rated output can be achieved.
12、 Normal operation
During boiler operation, it is required to ensure that the water level of the boiler is normal, the steam pressure is stable, the boiler room is kept clean, the handover work is done well, and the human factor is given priority. Strengthen the observation of various mechanical equipment and instruments. Ensure safety and reliability, prevent accidents, pay attention to saving coal, and the stoker should regularly summarize experience and continuously improve operational skills.
1. Water supply requirements:
It is best to perform external chemical treatment on boiler feedwater, and the water quality should meet the requirements of GB 1576-2001 "Industrial Boiler Water Quality". The total hardness of the feedwater should not exceed 0.03mmol/L. Please refer to the boiler water quality requirements for specific regulations. 2. Water level in the pot:
Regularly pay attention to changes in the water level inside the pot, keeping it within a range of 50 millimeters of normal water level, and not exceeding or falling below the highest or lowest water level. The water level in the water level gauge generally has a slight shaking phenomenon. If the water surface is still, there may be blockage in the water level gauge, and it should be rinsed immediately.
3. Water level gauge:
Each shift should flush the water level gauge at least once to keep the glass of the gauge regularly clean, ensuring that the water level is clear, correct, and reliable. If water or air leakage is found in the glass gasket, it should be filled quickly. If the glass is blurry or the water level line is unclear, and even after rinsing, it still has no effect, it should be replaced.
4. Water supply equipment:
⑴ Whether the running feedwater pump is normal should be checked during shift handover, and any faults should be repaired immediately.
⑵ Boiler feedwater should adopt continuous water inlet as much as possible, and control the fine water flow at the outlet valve of the water pump.
5. Steam pressure:
Regularly pay attention to pressure changes, try to maintain stable pressure inside the pot, and do not exceed the maximum allowable working pressure.
6. Pressure gauge:
The pressure gauge bend should be flushed once per shift to check if the pressure gauge is normal. If the pressure gauge is found to be damaged, it should be immediately shut down for repair or replacement. The accuracy of the pressure gauge shall not be less than level 2.5.
7. Safety valve:
1. The boiler should adjust the working pressure of the safety valve during the initial ignition according to the pressure specified in Table 7-2 of Article 143 of the "Steam Boiler Safety Technical Supervision Regulations" of the State Administration of Labor.
① The adjustment method for the safety valve is to remove the opening pin, remove the top cover, loosen the hexagonal lock nut, and then turn the adjusting screw to loosen or tighten the spring to achieve the required exhaust pressure of the safety valve. Tighten the locking nut after adjustment, and then install the remaining parts properly.
② The set pressure of the safety valve is 0.4MPa for the rated steam pressure of the boiler model, and 0.43MPa for the set pressure of the safety valve. After the safety valve reaches the specified set pressure, it should be sealed with lead. Unless the safety valve is calibrated, it is not allowed to dismantle the lead seal without authorization at any time.
③ When adjusting the safety valve, the water level in the drum should be slightly lower than the normal water level, and be prepared to allow water to enter at any time after the safety valve is opened.
④ Do not tap any part of the safety valve. Only the control rod on the valve can be used to open the safety valve.
⑤ The boiler must not be used before the safety valve is adjusted.
Regular attention should be paid to whether the safety valve is functioning properly. Due to the effect of water vapor, in order to prevent the valve disc and seat of the safety valve from sticking, regular exhaust tests should be conducted every 2-4 weeks to verify the opening and closing function of the safety valve.
8. Discharge valve:
Regular pollution discharge (refer to Article 13 "Pollution Discharge")
9. Normal operation;
(1) The normal combustion conditions inside the furnace should be:; The fire bed is flat, the flames are dense and uniform, the bright yellow flame without cold air is neat and consistent, and the smoke coming out of the chimney is light gray,. The negative pressure of the furnace is maintained at 19.6-29.4 megapascals (2-3 millimeters of water column), and the exhaust temperature is around 250 ℃.
(2) It is necessary to continuously adjust the boiler load and combustion chamber operation according to the steam consumption situation to ensure the stability of boiler steam pressure. The steam department should strengthen communication with the boiler. When there is a change in steam consumption, it is best to notify the boiler operator half an hour in advance. When the boiler load increases, first increase the flue gas regulation amount, and then increase the coal seam thickness. When the boiler load decreases, first close the flue gas control valve and then thin the coal seam thickness.
(3) Boilers are suitable for burning bituminous coal and coal shavings (0-5mm). The coal used for combustion should preferably be sieved, with a maximum coal block size not exceeding 30 millimeters.
(4) The thickness of the coal seam is generally determined by the stoker according to the specific situation, and it is only changed when the coal type is changed or the boiler load changes dramatically.
(5) The higher the moisture content of the fuel, the longer the preparation time for ignition. For high volatile fuels (bituminous coal), in order to prevent coal drying and prevent small particles from burning, coal should be piled up and watered before being put into the furnace. The watering should be uniform and the amount of watering should ensure ignition. Generally, it is advisable to knead it into a loose ball with a moisture content between 10-12. Anthracite does not need to be watered.
(6) Boiler and accessories (including pipelines, valves, instruments) are safe, sensitive, and reliable.
(7) The boiler room is clean and tidy, with bright lighting.
(8) Both parties involved in the shift handover must ensure thorough and serious handover, and record the situations and issues encountered during the handover in the operation log book.
13、 Pollution discharge
Generally, water contains more or less minerals. After the water enters the boiler for gasification, minerals remain in the boiler and concentrate to a certain extent before settling in the boiler. With high evaporation and long operation time, there will be more sediment. To prevent boiler damage caused by scale and slag, it is necessary to ensure the quality of the water supply. The alkalinity of the boiler water should not exceed 1.25 milliequivalents per liter. If it exceeds the above range, the boiler water should be discharged. When the testing conditions are not yet complete, general users should regularly discharge pollutants according to specific situations, such as once a day or once a shift.
Attention should be paid to the following matters when discharging pollutants:
If two or more boilers use the same sewage main pipe and there is no check valve on the sewage pipe, attention should be paid to:
(1) It is prohibited to discharge two boilers simultaneously.
(2) If another boiler is undergoing maintenance, the boiler under maintenance must be separated from the sewage pipeline before draining.
2. Wastewater discharge should be carried out at low loads and high water levels. When discharging, close attention should be paid to the water level inside the furnace, and it is advisable to lower the furnace water level by 25-50 millimeters each time.
3. After the discharge is completed and the discharge valve is closed, the tightness of the discharge valve should be checked. The inspection method is as follows:; After closing the drain valve for some time, manually test the mold on the pipeline of the second drain valve leaving the boiler. If the drain valve pipeline is not cooled, there must be leakage in the drain valve.
14、 Shutdown of furnace
1. There are generally three situations for boiler shutdown:
(1) By the week During holidays or other circumstances, the boiler should be temporarily shut down when steam is not used in the short term
(2) To clean, inspect or repair, the boiler should be completely shut down when the boiler water needs to be drained.
(3) In case of special circumstances, emergency shutdown is required for safety and reliability reasons.
The above three types of shutdowns have different requirements due to different situations. The specific explanations are as follows:
1. Temporary shutdown due to malfunction. First, close the flue gas control valve, open the furnace door, put in new coal pressure fire, and quickly deal with the relevant faults. If the fault cannot be resolved within 1-2 hours, it should be dealt with according to the temporary shutdown situation and continue to resolve the fault.
2. Temporarily shut down the furnace
Temporary shutdown is planned, and in addition to paying attention to safety and proper maintenance of equipment during shutdown, coal and water conservation should also be achieved.
The specific steps are as follows:
(1) Before shutting down the furnace, depending on the steam usage, coal feeding can be stopped 20-30 minutes in advance and the regulating valve can be closed.
(2) After the boiler cools down, the water level should decrease, so when the boiler is shut down, the water level should be higher than the normal water level.
(3) After stopping the steam supply Close the main steam valve and flue gas control valve when the pressure inside the boiler drops to zero.
3. Complete shutdown:
Complete shutdown should be planned, usually every 1-3 months of operation, and attention should be paid to safety and equipment maintenance during shutdown After following the steps for temporary shutdown, wait for the boiler water to slowly cool down to below 70 before releasing it At this point, the safety valve must be lifted first to allow the inside of the drum to communicate with the atmosphere If it is necessary to shorten the cooling time, cold water can also be introduced through the water supply pipeline, and hot water can be discharged through the sewage pipeline, but the water level must not be lower than the normal water level After the boiler water is discharged, open the manhole and hand hole and rinse the water stains with clean water.
4. Emergency shutdown:
When encountering any of the following situations during boiler operation, emergency shutdown should be taken and relevant departments should be notified.
(1) When the boiler water level drops below the water level limit specified in the boiler operation regulations;
(2) Continuously increasing the supply of water to the boiler and taking other measures, but the water level continues to decline;
(3) When the boiler water level has risen above the upper limit specified in the operating regulations;
(4) All water supply machinery has failed;
(5) All water level gauges or safety valves have failed;
(6) Boiler components are damaged, endangering the safety of operating personnel;
(7) Other common operating conditions; And it exceeds the allowable range for safe operation.
5. Emergency shutdown focuses on preventing the expansion of accidents, and the specific steps are as follows:
(1) Close the smoke control door first.
(2) Quickly scoop out the coal stored in the furnace and clear out the unused coal.
15、 Maintenance and upkeep
1. Pay attention to the following points during the operation of the boiler:
(1) Positive pressure combustion or furnace smoke injection is not allowed as it can easily damage the coal filling hole cover.
(2) There should be no water accumulation on the bottom floor of the boiler to prevent moisture and corrosion.
2. The boiler should be inspected every 2-3 weeks during operation.
3. The boiler should be shut down for comprehensive inspection and maintenance every 3-6 months after operation.
(1) Inspect the inside and outside of the boiler, such as the welds on the compressed parts and whether there is corrosion inside and outside the steel plate. If serious defects are found, they should be repaired in a timely manner. If the defects are not serious, they should be repaired during the next shutdown. If suspicious areas are found but do not affect safety production, a record should be made for future reference.
(2) After inspection, apply boiler primer on the water surface to prevent corrosion.
4. The boiler and boiler base should be painted at least once a year.
5. There are two maintenance methods for boilers that are not commonly used: dry and wet methods. If the boiler is shut down for more than a month, dry maintenance method should be adopted, while wet maintenance method can be used if the boiler is shut down for less than a month.
(1) After the boiler is shut down, drain the boiler water and thoroughly remove the internal dirt. Dry it in the furnace with low heat (be careful not to use high heat). Then, put 10-30mm pieces of quicklime into separate trays and place them in the furnace drum, avoiding contact between quicklime and metal. The weight of quicklime is calculated at 8 kilograms per cubic meter of drum volume Then close the head hole, hand hole, and pipeline valve, and check them every three months. If the quicklime is crushed into powder, it must be replaced. When the boiler is restarted, remove the quicklime and plate.
(2) Wet maintenance method:
After the boiler is shut down, release the boiler water, thoroughly remove the internal dirt, rinse it clean, refill with treated water until full, heat the boiler water to 100 ℃, allow the gas in the water to be discharged from the furnace, and then close all valves. In cold climates, wet maintenance methods should not be used.
16、 Water quality requirements
The water quality requirements for boilers should comply with the relevant provisions of GB1576-2001 "Industrial Boiler Water Quality". Please refer to the table below for specific requirements:
Seventeen Inspection of pressure components and hydrostatic testing
1. According to the "Safety Technical Supervision Regulations for Steam Boilers" (96), if any of the following situations occur in the boiler, external inspection and overpressure test should be carried out on each pressure bearing component:
(1) After new installation, modification, and relocation.
(2) Stop running for more than a year and need to resume operation.
(3) After major repairs to the pressure components.
(4) When it is suspected that the equipment status must be checked based on the operation of the boiler.
2. The boiler should be completely shut down before inspection. Thoroughly remove internal scale, external smoke and dust,
The key inspection points are as follows:
(1) Is the welding seam of the drum normal and is there any leakage.
(2) Check for corrosion, groove deformation, and other phenomena inside and outside the boiler steel plate.
(3) Whether the horizontal pipe is bent, and whether there are cracks at the welds between the pipe end and the head or cylinder.
(4) Are there any suspicious points at the connection between the water supply pipe, sewage pipe, and one side of the drum.
3. If the corrosion is severe, strength calculation should also be done before conducting the overpressure test.
4. The test pressure is 1.5 times the working pressure.
5. Water pressure test steps:
(1) During the hydrostatic test, the inlet water temperature should be maintained at around 20-30 ℃. If the temperature is too low, dew may condense on the outer wall of the boiler, which can be confused with the occurrence of water seepage and other loose situations, making the inspection difficult. If the temperature is too high, water droplets may evaporate, and the leakage will not be detected.
(2) After the water is full, gradually increase the pressure for a tightness check, and tighten the nuts of the flange, manhole cover, and handhole cover if necessary.
(3) During the boiler water pressure test, the water pressure should slowly rise. When the water pressure reaches 0.4 MPa, the pressure rise should be paused to check for water leakage or abnormal phenomena. Then increase the pressure to 0.6 MPa and maintain it for 20 minutes. If the pressure does not decrease, reduce it to 0.4 MPa for inspection.
(4) Any situation discovered should be recorded for repair when reduced to atmospheric pressure.
6. Hydrostatic test:
Pressure bearing components are considered qualified if they meet the following conditions:
(1) There are no water droplets or mist on the metal walls and welds of the pressure bearing components.
(2) After the hydrostatic test, no residual deformation was found.
7. Safety measures and precautions:
(1) Strictly prohibit tightening flange bolts when the pressure exceeds 0.1MPa.
(2) During the hydrostatic test, there should be particularly clear isolation signs around the test site, and unauthorized personnel are not allowed to enter the test area.
(3) During the hydrostatic test, the operator shall not stand directly in front of the flange and valve.
(4) Personnel unrelated to the hydrostatic test are not allowed to stand in the test area for observation during the hydrostatic test.