Some standard content:
Machinery Industry Standard of the People's Republic of China
JB/T8594-1997
Ladle Refining Furnace
1997-07-25 Issued
Ministry of Machinery Industry of the People's Republic of China
1997-10-01 Implementation
JB/T8594-1997
This standard is formulated for the first time.
This standard must be used in conjunction with GB/T10067.2. Former
This standard is proposed by the National Technical Committee for Standardization of Industrial Electric Heating Equipment. This standard is issued by the Xi'an Electric Furnace Research Institute of the Ministry of Machinery Industry. The main drafting units of this standard are: Xi'an Electric Furnace Research Institute of the Ministry of Machinery Industry, Changchun Electric Furnace Factory, and Northeastern University. The main drafters of this standard are: Hou Jinzhen, Yang Jingyuan, and Yan Liyi. 1 Scope
Machinery Industry Standard of the People's Republic of China
Ladle Refining Furnace
JB/T85941997
This standard specifies the requirements for ladle refining furnaces, including specifications, technical requirements, test methods, inspection rules, ordering and supply, etc.
This standard applies to ladle refining furnaces for arc heating, refining or vacuum degassing of primary molten steel. The main varieties are LF, VOD, VD and LFV. Other varieties of ladle refining furnaces can also be implemented as a reference. 2 Referenced Standards
The provisions contained in the following standards constitute the provisions of this standard through reference in this standard. At the time of publication of the standard, the versions shown are valid. All standards will be revised, and parties using this standard should explore the possibility of using the latest version of the following standards. GB/T10067.1-88 Basic technical conditions for electric heating equipment Part 1 General part GB/T10067.2-88 Basic technical conditions for electric heating equipment Part 2 Electric arc furnace for steelmaking GB5959.2--86
GB50056--93
GB/T.6542—86
ZBK60001-88
Mechanical industry standard
3 Definition
Safety of electric heating equipment Part 2 Special requirements for electric arc furnaces (eqvIEC519-4-1997) Design specification for power installations of electric heating equipment
Test methods for direct electric arc furnaces (eqvIEC676-1980) Method for compiling product models of electric heating equipment
General technical requirements for welded parts
Except for the following supplementary provisions, the rest shall be in accordance with the provisions of Chapter 3 of GB/T10067.2. 3.1 Ladle refining furnace
A complete set of equipment equipped with arc heating device or exhaust device, molten steel stirring device and charging device, etc., which uses the ladle to cover or place the ladle in a vacuum container to maintain the required process atmosphere in the ladle. 3.2 Rated capacity: t
The nominal mass of molten steel contained in the ladle specified in the design of the ladle refining furnace and marked on the nameplate. 3.3 Power consumption, kW. h/t
The average value of the power consumed by the main circuit of the ladle refining furnace for heating the specified molten steel from the temperature at the beginning of power supply to the final temperature under rated heating conditions. 3.% Electrode unit consumption, kg/t
The average value of the electrode mass consumed for heating one ton of molten steel (electrode breakage is not included). 3.5 Ladle diameter, mm
The inner diameter of the upper opening of the ladle shell.
3.6 Free space, mm
When the ladle is filled with rated capacity of molten steel, the clearance distance between the upper surface of the ladle and the surface of the molten steel. 3.7 Average heating rate, ℃/min
The ratio of the temperature rise of the molten steel from the temperature at the beginning of power supply to the final temperature to the time required for heating. Approved by the Ministry of Machinery Industry on July 25, 1997
Implemented on October 1, 1997
3.8 Maximum heating rate, ℃/min
JB/T8594-1997
Refers to the heating rate of the straight line segment with the largest slope in the heating curve during the period when the molten steel rises from the lowest temperature to the final temperature during the refining process, and is used to express the maximum heating capacity of the ladle refining furnace. 3.9 Working vacuum, Pa
The rarefaction process of the gas during the refining of molten steel under working conditions. Absolute pressure values are usually used to represent 3.10 Pumping capacity, kg/h
The amount of air pumped per unit time under working vacuum conditions. 4 Product classification
4.1 Varieties and specifications
Ladle refining furnaces are divided into multiple varieties according to their functions, as shown in Table 1. 4.1.1
Arc heating, argon blowing and stirring
Vacuum oxygen blowing, decarburization, hydrogen blowing and stirring
Vacuum degassing, argon blowing and stirring
Arc heating, vacuum degassing, argon blowing and stirring
4.1.2 The same variety of ladle refining furnaces is divided into multiple specifications according to rated capacity. The recommended values of its actual capacity, ladle diameter, transformer rated capacity, electrode diameter and vacuum tank inner diameter are shown in Table 2. Table 2.
Rated capacity t
（Actual capacity t）
(15~25)
(35~45)
(55~65)
(65~75)
（80~120)
（130~170）
(180~220)
(230~270)
Ladle diameter
Transformer rated capacity
Electrode diameter
Inner diameter of vacuum tank
3800~4100
4800~5000
5300~5500
5400~5600
5800~7000
6300~7500
Rated capacity t
（Actual capacity t）
(270~300)
(320～380）
Note: 20t is not recommended.
4.2 Model
Ladle diameter
JB/T8594—1997
Table 2 (end)
Rated capacity of transformer
The product models of ladle refining furnace are as follows according to ZBK60001:口—
口1口
Enterprise code
Remodel code
Electrode diameter
Rated capacity of transformer, MVA
Rated capacity, t
Variety code
Inner diameter of vacuum tank
For example: The rated capacity of transformer produced by the factory with enterprise code .TL is 40t, The model of the ladle refining furnace with a transformer rated capacity of 6-MVA and a variety code of LF is:
LF--40-6-TL
4.3 The following main parameters should be listed in the enterprise product standard of the ladle refining furnace: a) Rated capacity, t;
b) Ladle diameter, mm;
c) Free space, mm;
d) Transformer rated capacity, MVA;
e) Transformer primary voltage, kv,
f) Transformer secondary voltage, V,
g) Transformer secondary rated current, A;
h) Reactor rated capacity, kva r (when there is a reactor); i) graphite electrode diameter, mm;
j) electrode distribution circle diameter, mm; bzxZ.net
k) maximum electrode movement distance, mm;
1) maximum electrode movement rate (rise/fall), m/min; m) ladle car (or) vacuum tank car movement speed, m/min; n) furnace cover or vacuum tank cover lifting height, mm; o) vacuum tank inner diameter (applicable to VOD, VD, LFV type ladle refining furnace), mm; p) vacuum tank height (applicable to VOD, VD, LFV type ladle refining furnace), mm; q) working vacuum degree, Pa;
r) exhaust capacity, kg/h;
s) primary side impedance unbalance coefficient, %; t) resistance and reactance value of high current line, ma; u) power consumption, kW·h/t;
v) electrode unit consumption, kg/t;
JB/T8594—1997
w) heating rate (including average heating rate and maximum heating rate), ℃/min; x) cooling water consumption, m/h;
y) compressed air consumption, m/min;
z) argon consumption, 1/min;
aa) oxygen consumption, Nm/h;
bb) metal structure mass, t.
5 Technical requirements
5.1 General requirements
The ladle refining furnace shall comply with the relevant provisions of Chapter 5 of GB/T10067.2. When there is a discrepancy between the provisions of the standard and this standard, this standard shall prevail.
For VOD type ladle refining furnace, the carbon monoxide content in the air within 1m around the control room and equipment shall not exceed 30mg/m. 5.2 Supplementary requirements for design and manufacture
5.2.1 Overall design
The ladle refining furnace is mainly composed of the ladle (including sliding water nozzle and argon blowing device, etc.), electrode lifting device, bridge frame and furnace cover (or vacuum tank cover) lifting mechanism, ladle car (or vacuum tank car and driving mechanism, vacuum tank, vacuum tank cover, charging hopper, hydraulic system, cooling water system and compressed air, oxygen and argon supply system, high current circuit and electrical control system. The design of the ladle refining furnace should focus on the assembly rigidity and interlocking protection of each part, and its safety measures should be reliable. The electrical control device, hydraulic system and water cooling system should be reasonably arranged as close to the heating station and vacuum station as possible while ensuring safety and convenient maintenance. When it is necessary to equip a temperature measuring and sampling device, it can be installed according to the following procedures: 9.2 proposed. 5.2.2 Ladle
The ladle should be welded from steel plates into a barrel or cone. The welds should be reliably welded to form a rigid structure. The welds should be inspected in accordance with the machinery industry standard "General Technical Requirements for Welded Parts".
The design of the ladle size should be conducive to the stirring of the molten steel and the improvement of the life of the furnace lining. The sliding water nozzle should be easy to operate and move smoothly, and there should be no jamming during operation. The fluorine blowing device should work reliably, and the air-permeable bricks must not be blocked. When there are special requirements, it can be proposed according to 9.2. 5.2.3 Electrode lifting device
The device consists of an electrode cross arm, a column and a guide wheel. The cross arm and the column should have sufficient rigidity, and there should be good insulation between the two. The guide wheel (or trolley) and the column should run smoothly without There should be no jamming phenomenon. When there are special requirements, they can be proposed according to 9.2. 5.2.4 Furnace cover
The furnace cover is divided into two categories: refractory furnace cover and water-cooled furnace cover. It should be equipped with feeding holes and operation holes, etc. The arch of the refractory furnace cover should be reasonable to prevent collapse during operation. The water inlet and outlet of the water-cooled furnace cover should be reasonably set, the water flow should be smooth, and there should be no dead corners.
When there are special requirements, they can be proposed according to 9.2. 5.2.5 Bridge and furnace cover (or vacuum tank cover) lifting mechanism The bridge is a steel frame structure, which should have sufficient rigidity and strength to stably support the lifting device and electrode lifting device. The furnace cover (or vacuum tank cover) lifting mechanism should have sufficient strength to move smoothly when lifting the furnace cover (or vacuum tank cover), and there should be no jamming phenomenon. 5.2.6 Ladle car (or vacuum tank car) and drive mechanism JB/T8594--1997
Ladle car (or vacuum tank car) is a steel frame structure, which should have sufficient rigidity and strength. The drive mechanism should be able to run smoothly under the maximum load without slipping.
When there are different requirements for the power supply mode of the drive mechanism, it can be proposed according to 9.2. 5.2.7 Vacuum tank and vacuum tank cover
The vacuum tank and vacuum tank cover are welded with steel plates and should have sufficient rigidity and strength. The weld inspection should be carried out in accordance with the mechanical industry standard "General Technical Requirements for Welded Parts". Under working conditions, there should be good sealing between the vacuum tank and the vacuum tank cover. 5.2.8 Feeding system
The gate of the system controlling the feed port should operate reliably and should not be stuck. The vacuum feeding system should also have good airtightness. When there are special requirements, it can be proposed according to 9.2. 5.2.9 Water, gas, oxygen and argon supply systems
5.2.9.1 The water cooling system can be an open or closed water supply system. The water cooling system should be equipped with water temperature and water pressure monitoring and protection links, and each branch should also be equipped with a stop valve.
5.2.9.2 The oxygen and argon supply systems should be equipped with flow, pressure monitoring and protection links. The flow should be remotely controlled when necessary. 5.2.9.3 The compressed air system should be equipped with an air filter and have flow and pressure regulation functions. When there are special requirements, they can be proposed in accordance with 9.2. 5.2.10 High current lines
5.2.10.1 The influence of electromagnetic induction should be considered when designing components close to the conductors of high current lines, such as electrode water cooling rings, supports and fasteners, and parts in electrode clamps. 5.2.10.2 The busbars and cables of high current lines should have sufficient conductive cross-sections, and the connections should ensure good conductivity. The water-cooled cable should have sufficient deflection.
During operation, the maximum temperature rise of naturally cooled bare busbars and cables (including connections) should not exceed 50°C, and the maximum temperature rise of water-cooled cable connections should not exceed 40°C.
5.2.10.3 After clamping the electrode, the electrode chuck should ensure good conductivity. When the electrode moves up and down, there should be no slippage between the electrode and the chuck.
5.2.11 Electrode movement adjustment system
5.2.11.1 The maximum movement distance of the electrode should ensure that the electrode can be lifted to more than 100mm below the bottom edge of the furnace cover in the case of the longest electrode. 5.2.11.2 The electrode movement adjustment system shall be able to meet the following requirements: a) It shall be able to make the electrode automatically ignite the arc; b) It shall be able to automatically eliminate the short circuit between the electrode and the boiler water; c) It shall be able to automatically maintain the given input power of each phase; d) The electrode lifting shall be able to realize the switch between automatic control and dynamic control; e) The specifications and dimensions of the connecting busbar and cable shall ensure that the heating temperature thereof under the load does not exceed the allowable value. When there are special requirements, it shall be proposed according to 9.2.
5.2.12 Oxygen blowing device
The oxygen blowing device shall be equipped with an oxygen gun height display device: to control the distance between the nitrogen gun and the molten steel. The mechanism shall operate smoothly and reliably. The oxygen gun water cooling system shall be set separately and shall be equipped with a water leakage alarm, pressure display and interlocking protection device to ensure safe operation. When there are special requirements, it shall be proposed according to 9.2. 5.2.13 Vacuum system
The vacuum system consists of a vacuum pump, a cooling and dust removal device, a vacuum measuring instrument, a main stop valve and a vacuum pipeline. When there are special requirements, it can be implemented according to 9.2. 5.2.13.1 The vacuum pump is the main body of the vacuum system, which is divided into two types: steam jet pump and water ring pump. The water drum, ejectors at all levels and condensers of the vacuum pump should be subjected to an air tightness test, the test pressure is 0.2MPa, and there should be no leakage for 30min. The steam drum should be subjected to a pressure resistance test, the test pressure is 1.6MPa, and there should be no leakage for 30min.
JB/T8594-1997
5.2.13.2After the vacuum pump is installed, 0.25MPa compressed air should be passed through, and the pressure should be maintained for 24h. The pressure drop per hour should not be greater than 2%. 5.2.13.3 The cooling and dust removal device should be cleaned by a cleaning system. The dust removal mechanism should be easy to operate. 5.2.13.4 When installing the vacuum measuring instrument, it should be as close to the vacuum tank as possible. 5.2.13.5 The main stop valve can be opened reliably under vacuum. 5.2.13.6 The vacuum pipeline should be welded into a circular body with steel plates. The weld inspection should be carried out in accordance with the mechanical industry standard "General Technical Requirements for Welding Parts". The connection between the flanges should be sealed reliably and should be tested for airtightness. The test pressure is 9.2MPa and there should be no leakage for 20min. 5.2.14 Electrical control system.
The system consists of an electrical control cabinet
contactor and an electrical operating table. The system should be installed with various instruments and all internal wiring as required before leaving the factory. The electrical control cabinet (combination) is used to install various electrical instruments and components. The control cabinet (table) should have a signal display and button control system to indicate and control the actual working conditions. 5.3 Performance requirements
Under the conditions of actual capacity and rated capacity of the transformer, the ladle refining furnace should be able to work continuously and reliably and meet the following requirements. 5.3.1 Insulation resistance
The insulation resistance of the large current line to the ground in the cold state and without water should not be less than 0.5MQ. 5.3.2, primary side impedance unbalance coefficient
In the rated working state,
The secondary side impedance unbalance coefficient is not greater than?
5.3.3 Electrode movement adjustment system characteristic indicators The electrode movement adjustment system characteristic indicators shall comply with the provisions of Table 3. When there are special requirements, Table 3 can be proposed according to 92
, rated capacity,
Maximum rising speed of the electrode plate, m/min
Electrode speed reduction technology mnin
Electrode response time
·Insensitive graph
>20~40
5.3.4Power consumption, electrode unit consumption, average heating rateThe power consumption, electrode unit consumption, average heating rate and maximum heating rate of the ladle refining furnace are recommended to be in accordance with the specifications in Table 4. Table 4
Rated capacity, t
Power consumption, kW·h/t,
Electrode unit consumption, kg/t,
Average heating rate, C/min,
Maximum heating rate, C/min, ≥
Note: The average heating rate is not used as an assessment indicator. 5.4Safety requirements
The safety of the ladle refining furnace shall comply with the relevant provisions in GB50056 and GB5959.2 and the following supplementary provisions. When there are additional requirements, they can be proposed according to 9.2.
5.4.1 The length of the water inlet and outlet hoses used for all cooling water pipes and water-cooling cables under different working voltages shall be designed according to the requirement that the leakage current in a single branch is not more than 20mA. The hose itself shall have sufficient electrical insulation performance and mechanical strength. 5.4.2 Necessary protective nets and covers shall be installed at the accessible places of all power supply parts of the ladle refining furnace. The ladle, ladle car, bridge and electrode column shall be reliably grounded.
5.4.3 An electrical interlock shall be installed between the furnace cover (or vacuum tank cover) and the ladle car, and the ladle car shall not move when the furnace cover (or vacuum tank cover) is not lifted into place.
5.4.4 The ladle refining furnace with a vacuum tank shall be equipped with a steel leakage alarm device. 5.4.5 All pipelines and valves of the oxygen blowing device must be degreased. 5.4.6. The ladle trunnion shall be inspected for defects such as pores and cracks. There shall be no cracks and permanent deformation after a test suspension of 30 minutes at 1.5 times the maximum load.
5.4.7 The vacuum chamber shall be subjected to an overall negative pressure test. The pressure rise rate after pressure maintenance shall not be greater than 1kPa/h. 5.4.8 The vacuum pump shall be subjected to pressure resistance and air tightness tests. 5.5 Requirements for complete sets
5.5.1 In the enterprise product standards, the complete set supply scope of the ladle refining furnace specified by the supplier shall be listed, which shall generally include the following items: a) Complete set of mechanical equipment for the ladle refining furnace;
b) Special transformer for the ladle refining furnace;
c) Reactor (when there is a reactor);
d) Electrode regulator;
e) High and low voltage power distribution devices;
f) Control cabinets and tables for the electrical system, hydraulic system, pneumatic system and water cooling system; g) Vacuum pump system (when necessary);
h) Busbars and cables for high current lines;
i) Spare parts;
i) Factory documents (including product manuals and necessary design drawings). In the enterprise product standards for ladle refining furnaces, the specific contents of the above items shall be listed, including models, specifications and quantities. If the purchaser has different requirements for the items specified by the supplier, they may be proposed in accordance with 9.2. 5.5.2 When the following accessories or devices are required, they may be proposed in accordance with 9.2, and their technical conditions shall be agreed upon by the supply and demand parties. a) Smoke exhaust and dust removal device for ladle refining furnace:
b) Automatic feeding system;
c) Electronic automatic weighing and accessories;
d) Ladle lifting device;
e) Computer electrode adjustment system;
f) Computer screen monitoring system:
g) Computer control of vacuum system.
5.5.3 The installation materials and consumable materials for the operation of the ladle refining furnace are not within the scope of complete set supply. When the purchaser has requirements (see 9.2), it should be noted in the contract and a list should be provided.
These materials include:
a) graphite electrodes and their joints;
b) refractory materials;
c) hydraulic media;
d) cooling water inlet and outlet main pipes, as well as cooling water branches and mounting frames not fixed on the ladle refining furnace; e) external connecting pipelines between components in the hydraulic system, as well as hydraulic pipelines and mounting frames not fixed on the ladle refining furnace; f) air inlet main pipes of compressed air, steam, oxygen and argon supply systems, as well as branches and mounting frames not fixed on the ladle refining furnace; g) external cables, wires and pipes connecting various electrical cabinets and tables; 7
JB/T8594—1997
h) cables, wires and pipes connecting the ladle refining furnace transformer with various electrical cabinets and tables. 5 Test methods
The test methods for ladle refining furnaces shall be carried out in accordance with Chapter 6 of GB/T10067.2 and the relevant provisions of GB/T6542 and the following supplementary provisions. 6.1 Measurement of power consumption, average heating rate and maximum heating rate of ladle refining furnaces 6.1.1 Measurement conditions
a) The furnace condition is normal and the process is stable; b) The temperature should be measured by inserting a thermocouple 300mm below the steel liquid surface without arcing c) During the measurement process, the number of temperature measurements shall not exceed 3 times; d) Before the ladle receives molten steel, the ladle shall be baked to above 950C: e) There shall be no unmelted furnace charge (such as alloy material, slag material, etc.) in the ladle; f) The ladle must be a hot ladle used for 3 consecutive furnaces; g) The measurement result shall be the arithmetic mean of the test values of 5 consecutive furnaces. Specific test conditions should be specified in the enterprise product standards, such as slag making conditions and workers' kneading level. 6.1.2 Measurement method
6.1.2.1 Measurement of power consumption
Directly read the indication value of the active watt-hour meter connected to the main circuit at the beginning and end of power transmission. Then calculate EEpo
according to the following formula: ep---power consumption, kW·h/t
E,—the reading of the active watt-hour meter at the end of refining, kW·hEpo—the reading of the active watt-hour meter at the beginning of power transmission, kW·h; G—the mass of molten steel, t.
6.1.2.2 Measurement of average heating rate
It is equal to the ratio of the temperature rise of molten steel to the arc heating time: V.
Where: V.Average heating rate, ℃/min; 9—Refining end temperature, ℃
. Power transmission start temperature, ℃;
tArc heating time, min.
6.1.2.3 Measurement of maximum heating rate
Under continuous power-on condition, measure the temperature of molten steel 5 minutes after the alloy material is melted and the refining slag is formed; measure the temperature of molten steel before the alloy is adjusted; read the time t\ required for heating between two measurements, and then substitute it into the following formula to calculate, 6 -
Where: Vx
Maximum heating rate, C/min
6. -—The temperature of molten steel measured before alloy composition adjustment, ℃; α-—The temperature of molten steel measured 5 minutes after the alloy material is melted and the refining slag is formed, ℃: t'The time required for heating, min.
6.2 Measurement of electrode unit consumption g
Electrode consumption G. Under the measurement conditions of 6.1.1, the mass of the electrode consumed in 10 consecutive refining tests is subtracted from the mass of the electrode that was not used due to breaking during the test to obtain:
Electrode unit consumption gel is the ratio of the electrode consumption G to the total mass G of the molten steel refined in the 10 refining tests, expressed by the following formula: 8
Where: gel—electrode unit consumption, kg/t;
Gel——electrode consumption, kg;
GThe mass of molten steel, t.
JB/T8594—1997
6.3 Inspection of ladle car (or vacuum tank car) and driving mechanismGa
On the premise that the ladle car is load-bearing, check the starting and stopping working conditions of the ladle car (or vacuum tank car) on the full stroke, and measure its running speed. The ladle car (or vacuum tank car) should run smoothly, and the parking at each station should be accurate and reliable. The test should be repeated at least twice. Note: When the manufacturer does not have the vehicle body load operation test, only the no-load operation test can be carried out, and the load test can be carried out on the user's site. 6.4 Inspection of the furnace cover (or vacuum tank cover) lifting mechanism Under actual working conditions, install the electrode and check the lifting height of the furnace cover. The furnace cover should be lifted smoothly. The test should be repeated at least twice. 6.5 Inspection of the electrode lifting device
Under the conditions of installing the electrode and connecting the soft cable, check whether the maximum lifting distance and lifting speed of the mechanism meet the requirements, and whether the contact between the column and the guide wheel (trolley) is good in the full stroke. If the mechanism is equipped with an intermediate mechanical positioning device, the reliability of the device should be checked at the same time. The test should be repeated at least 3 times.
6.6 Inspection of the electrode chuck
Use an electrode model with the same diameter to clamp the electrode with the chuck first, and then release it. The test should be repeated at least 3 times. 6.7 Inspection of the working condition of the hopper
6.7.1 When the hopper is empty, check the opening size and closing position of the hopper gate. The mechanism should move smoothly, reliably and accurately. 6.7.2 For the vacuum hopper, check the stability of the hopper and cylinder movement mechanism and the reliability of the installation of the whole device without adding materials. 6.7.3 Check whether the installation of all sealing points is reasonable and the sealing is good. 6.8 Inspection of the connection of the high current line
Check whether the connection of each connection part of the high current line is firm and reliable, and check whether the contact of the connection is good by measuring the resistance. The measurement method is carried out according to 6.8 in GB/T10067.2. After installation, check once, and after refining 2 furnaces with power on, check again after power off. 6.9 Measurement of the temperature rise of the high current line
Measure immediately after working continuously for one furnace under the actual working conditions of the ladle refining furnace. The measurement points are as follows:
a) Any point on the outer surface of the conductor;
b) Any point on the surface of the connection between conductors; c) Any point on the outer surface of the connection of the water-cooled cable end. The temperature rise value is the measured value minus the ambient temperature. 6.10 The measurement of insulation resistance of high current lines shall be carried out in accordance with Article 4.1 of GB/T6542
6.11 The measurement of the characteristics of the electrode movement adjustment system shall be carried out in accordance with Article 4.3 of GB/T6542.
6.12 Three-phase short-circuit test
Perform in accordance with Article 4.5 of GB/T6542.
6.13 The inspection of the cooling water pressure loss, insufficient flow and excessive outlet water temperature alarm system shall be carried out according to the actual working conditions of the system. The alarm test for excessive outlet water temperature can be carried out by analog signal method, and the test shall be repeated at least 3 times.
6.14 The inspection of the correctness and reliability of the action of each interlocking device and limit device can be carried out during the test of each mechanism or after the equipment is assembled according to the actual situation. The inspection shall be carried out under the following conditions: a) The mechanical limit device of the equipment has been reliably adjusted; 9
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