How to perform maintenance inspections on dry gas tanks? ?

This post was last edited by LightLead Guangzhou on 2016-5-14 14:09: Dry gas holder

I don’t quite understand it, but I’m still going to participate. I’ll support you a lot – keep it up!

1 An application is required to enter a confined space for work. 2 Approval is necessary before entering a confined space for work. 3 Requirements for entering a confined space: 3.1 When working inside containers or equipment, a safety ladder must be set up according to the depth of the equipment, along with rescue ropes to be used in emergency situations. 3.2 When working inside containers or equipment, ventilation measures should be taken depending on the specific working conditions. In containers and equipment with poor ventilation or very small volumes, workers should carry out work in intervals and must not force continuous operation. 3.3 When working inside containers or equipment, there must be a dedicated person to supervise the work. For particularly hazardous tasks such as entering gas tanks, in addition to having a designated supervisor, the Safety and Environmental Protection Department should also send personnel to monitor the site. 3.4 Before entering the container or equipment, the pipes connected to it should be disconnected and blind flanges installed; the electrical supply should be cut off, and “Do Not Operate” signs should be placed on the pipe valves and electrical switches to prevent accidental activation by others. 3.5 All manholes, access holes, and any vents must be opened, and removed covers and other accessories must be placed safely to prevent them from falling and causing injury. 3.6 When entering toxic container equipment that cannot be thoroughly cleaned, maintenance personnel shall wear appropriate personal protective equipment and gas masks; they should also pull the breathing tube outside the tank to ensure ventilation, and the supervisor must not leave the area. 3.7 Personnel entering containers or equipment for maintenance are prohibited from wearing synthetic fiber clothing or shoes with metal studs. 3.8 When performing gas welding or cutting inside containers or equipment, the worker must first conduct a trial cut to ensure safety and normal operation before entering the container or equipment to carry out the work. After the welding work is completed and the welder leaves, the acetylene torch must not be left inside the tank to prevent acetylene leakage. 3.9 When entering containers or equipment for work, the application period for a permit shall not exceed one day at a time. If the work is interrupted for some reason or if the safety conditions change, a new “Permit for Working in Confined Spaces” must be obtained. 3.10 Upon completion of the work, the maintenance personnel and supervisors shall jointly inspect the inside and outside of the tank; once everything is confirmed to be in order, they shall sign in the acceptance section of the work permit before the maintenance personnel can seal all access openings. 4 Supervision is required; responsibilities of the supervisor 4.1 The supervisor is responsible for overseeing and ensuring the safety of those working in confined spaces ； Generally, more than 2 supervisors are assigned; strong male employees take on the responsibilities of supervision and protection, and sign to confirm on the work permit. 4.2 Understand the potential hazards, so as to be able to promptly detect abnormal behavior among workers and make appropriate judgments. Maintain contact and communication with the workers, and observe their condition. 4.3 When an anomaly is detected, immediately issue an evacuation alert to the workers and assist them in escaping from the confined space, while also calling for emergency assistance right away. 4.4 Master the basic knowledge of emergency rescue. 5 Responsibilities of Operators 5.1 Responsible for entering confined spaces to carry out tasks while ensuring safety. Before starting the task, one should understand its content, location, time, and requirements, as well as be aware of the potential hazards involved and the safety measures that need to be taken. 5.2 Verify the implementation of safety protection measures. 5.3 Comply with the safety procedures for working in confined spaces, and use the safety equipment and personal protective gear designed for such work properly. 5.4 Necessary and effective two-way communication regarding safety, alarms, evacuation, etc., should be maintained with the supervisors. 5.5 Obey the instructions of the work supervisor; if it is found that the supervisor is failing to fulfill their duties, the work must be stopped and personnel must exit the confined space. 5.6 In the event of any abnormal conditions during the task, or if you feel unwell or experience difficulty breathing, you should immediately signal the task supervisor and evacuate the site promptly. I hope this can help you!

The maintenance work for gas tanks is extensive, and the construction process is also quite challenging. To ensure high-quality and rapid repair work, it is necessary to develop a reasonable construction plan as well as reliable safety and technical safeguards. It is essential to strictly adhere to all relevant technical regulations and standards, organize the construction carefully, and implement a comprehensive quality management system, so that all technical requirements for maintenance meet those specified in the construction drawings and relevant standards. To achieve rapid and safe construction, we conducted thorough research and analysis on the following key points in the implementation plan, and established corresponding safeguard measures: before the overhaul, it is necessary to replace and remove all the existing gas from the cabinet, as well as drain the water stored in the sink ； Multiple single-mast poles are installed at the center of the cabinet and on the sink platform to upright the overturned Tower I and place it on the support beams ； Precisely measure the actual deformation of the water tank and each tower section according to the structural construction drawings ； Process and manufacture steel components that need to be replaced due to deformation, and install the steel components ； Sink filling test ； Gas holder fast and slow lifting experiments ； Airtightness test. The main measures include those to prevent components from falling ； Measures to prevent deformation of steel components ； Measures for lifting and positioning steel components ； Emergency plans and rescue measures.

Implementation of the gas tank maintenance plan: 1) Drainage of the water tank and air replacement. Before draining the water tank, an elevation gauge is used to establish 8 evenly distributed reference points around the gas tank as settlement monitoring points, so as to compare the settlement differences before and after drainage of the entire gas tank, and to measure the settlement before and after filling the tank with water following the maintenance work； Collect first-hand basic data for the rapid and slow lifting experiments of the gas holder. Records are taken at four stage points corresponding to 1/4, 1/2, 3/4 of the sink’s drainage and filling rates, as well as the no-water condition. During this process, special attention should be paid to the center of gravity shift caused by Tower I in the water tank. Air replacement for Tower I: Use 4 5-t Gourd to secure Tower I and the tank platform. The gas supply pipeline was safely and reliably shut off; the electric vent valve at the top of the tower as well as the other 4 manual vent valves were slowly opened. The Roots blower located in the pressurization room was started to blow air into the gas tank, thereby removing the remaining gas from Tower I until sampling tests showed satisfactory results.

Wet spiral gas tanks were used in the past. Key points for reference: 1. The gas holder must be properly purged before entering the tower (it is recommended to purge the entire system during shutdown maintenance and to implement reliable shutdown measures); both the CO and oxygen detectors must show acceptable readings. After purging the gas with inert gas, air should be used for purification as well – it’s advisable to repeat this process several times to ensure no dead zones remain. Risk identification and operations shall be carried out in accordance with the safety standards for working with toxic and hazardous substances in confined spaces. After passing the replacement inspection, ensure proper ventilation when working inside the tower. 2. The main aspects inspected in a wet-type gas holder are the internal ladders, inlet and outlet pipes, whether there is any deformation in the internal connectors, the anti-corrosion treatment, as well as the thickness of the side walls and bottom plate. Internal waste collection and cleaning, etc. (The structure of the dry type is unclear; it is assumed that all moving parts whose connections cannot be inspected from the outside should be checked. It’s not known whether lubrication is provided or not.) Check the quality of the drawings and consult the manufacturer as well as those in the coal chemical industry). 3. During maintenance, be sure to avoid touching the side walls and the bottom, especially the bottom; once cracks or leaks appear there, it will be very difficult to locate them. (I encountered this when I modified the diameter of the inlet and outlet pipes) ； Some time ago, a colleague from the coal chemical industry also called to ask how to locate leaks at the bottom of their dry gas cabinets. ）