Gas preheater replacement

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This post was last edited by Drift with the current on 2017-11-7 at 20:06. Safety Plan for the Maintenance of Gas Preheaters No. 1 and No. 2 in the Coking Workshop. Maintenance schedule: Replacement of Gas Preheater No. 1 – November 3, 2017; replacement of Gas Preheater No. 2 – to be determined. Company’s on-site commander: Commander of the Coking Workshop: Person in charge of safety on site at the company: Person in charge of safety on site in the workshop: On-site coordination team for the workshop: Maintenance personnel: Machine repair team of the Coking Workshop (responsible); Coordination personnel: Flame adjustment team of the Coking Workshop (responsible). Maintenance measures: I. Preparation stage 1. Move valve No. 1, and clean the tar boxes of valves No. 2 and No. 3; it is required that the valves can be closed tightly after being moved and cleaned. Responsible. 2. Clear the access route for the preheater to enter, and bring the preheater to the site. Responsible for the delivery of the preheater and for clearing the access routes. 3. A lifting hole is created above the interstage preheater; the location of this hole is determined on-site. Responsible. 4. Replace the preheater bolts one by one to facilitate removal during replacement. Responsible. 5. Disassemble and position the lifting tools and emergency equipment on-site for testing. Responsible. 6. Before proceeding with the next tasks on site, the personnel involved shall undergo a second training session on the content of the tasks. II. Install blind flanges on valves 2# and 3# of the gas preheater. 1. Strictly restrict access to the maintenance area for unauthorized personnel; suspend all welding and heating operations within the affected area, except those approved separately. . 2. Coordinate well with the Production Department to ensure that the steam pressure for safe maintenance is above 0.3 MPa. Responsible. 3. Stop heating the coke oven, close valve #1, open valve #1 of the main gas return pipeline, and use steam to purge the main pipeline; take samples from the end sampling ports for testing to ensure that the gas concentration remains below 200 ppm. Responsible. *This step may not be achievable. 4. Begin simultaneous purging of the basement main steam pipeline upon connecting it; open valve 1#, close valves 2#, 3#, and 4#, and install blind flanges on valves 2# and 3#. During the operation, the CO concentration must not exceed 200 PPm; if necessary, wear a 5# gas mask. . *The water seal of valve 2# ensures that no blind flange is required when the gas supply is cut off. 5. Water is injected in front of Valve 2 through the pressure sampling pipe connected to the supervisor; water is injected into the tube side of the preheater and in front of Valve 3 through the liquid discharge valve of the preheater; water is injected into the shell side of the preheater through the steam valve of the preheater. . 6. Reduce the opening degree of the steam valve No. 1 to a level that allows it to prevent the gas from the return flue gas main from leaking in through valve No. 1, while at the same time avoiding excessive steam leakage; remove the bolts connecting the preheater to the gas pipeline and install blind flanges. . III. Disassembly of the preheater 1. Remove the connection bolts between the upper shell and the intermediate cylinder of the preheater. During this process, it is necessary to have an appropriate number of workers and to carry out the work in an orderly manner. . 2. Before lifting the upper shell of the preheater, conduct a second verification to ensure that the water inside the preheater has been replaced, and check the gas concentration at the work site to keep CO levels below 200 PPm; continuous monitoring should be carried out throughout the lifting process. Responsible. 3. Lift the upper shell of the preheater; the lifting process must be done smoothly to avoid sparks resulting from collisions. Once lifted, the upper shell should be placed outside the construction site. Responsible. 4. Lift the intermediate cylinder of the preheater; the lifting process must be done smoothly to avoid sparks resulting from collisions. Once lifted, the intermediate cylinder should be placed outside the construction site. Responsible. IV. Preheater Installation 1. Recheck the bolt holes in the intermediate cylinder of the preheater; if there are any dimensional deviations, corrections should be made off-site using welding. If welding on-site is indeed necessary, the relevant safety procedures for welding operations must be strictly followed. Responsible. 2. Lift the intermediate cylinder of the preheater and install the tightening bolts. Responsible. 3. Lift the upper shell of the preheater and install the tightening bolts. Responsible. 4. Conduct a second verification of the bolt tightening process after the preheater is installed. Responsible. V. Removing the blind flange: 1. First, remove the blind flange from valve No. 3, and tighten the connections on the flanges. Responsible. 2. Remove the blind flange of valve No. 2 and tighten the flanges; during this operation, the CO concentration must not exceed 200 PPm, and a Type 5 gas mask should be worn if necessary. . VI. Resuming heating: 1. Gradually open Valve 1#, and at the same time gradually close the steam valve and Valve 1# for venting. . 2. Re-enable heating in the basement. . VII. Safety Measures 1. The Safety and Environment Department, along with the workshop safety officer ××, shall inspect the equipment used on site to ensure that labor protection gear is appropriate and complete; unauthorized personnel are prohibited from entering the site. 2. The maintenance steps are carried out sequentially, with confirmation at each step. 3. There shall be no unauthorized hot work around the job site. 4. On-site, there is 1 35kg dry powder fire extinguisher and 4 5kg dry powder fire extinguishers. 5. When the working conditions are not suitable, preventive measures should be taken before stopping work; work can only resume after a new hazard assessment is conducted. Coking Workshop, October 2, 2017