# **Full Guide on Maintenance Operations for Pressure-Resistant Sealing Equipment After Use** ## **Introduction** The pressure-sealing technology is a crucial process in the maintenance and renovation of pipelines in the petroleum, natural gas, and chemical industries. It enables the safe sealing of pipelines without disrupting normal production. However, the equipment maintenance after the completion of the sealing operation is often overlooked, which directly affects the service life of the equipment and the safety of the next operation. According to statistics, over 60% of the failures of pressure-sealing equipment are caused by improper post-maintenance. This article will systematically introduce the **standardized maintenance process** for pressure-sealing equipment, covering all aspects of operation such as on-site cleaning, maintenance of key components, performance testing, and storage regulations. It also provides a maintenance checklist template to help users establish a scientific equipment management system. ## 1. On-site Handling after Pressure Sealing Operations ### **1. Equipment Disassembly Specifications** - **Pressure Confirmation**: First, ensure that the sealing head has completely released the pressure (the pressure gauge returns to zero) - **Sequential Disassembly**: First, dismantle the auxiliary pipelines (balance pipes, pressure measurement pipes) 2. Remove the connecting bolts of the occluder (using the diagonal loosening method) 3. Finally, remove the main blocking head (using a special lifting device) - **Marking Management**: Number each disassembled component and record its location ### 2. Pollution Cleanup - **Surface Cleaning**: - Oil stains: Use environmentally friendly solvents (such as biodegradable cleaning agents) - Scale formation: Soak in a 5%-10% citric acid solution - Special attention is required: concealed areas such as the sealing groove and the threads. - **Cleaning Standards**: Meet the requirements of JB/T 6896-2007 "Cleanliness for Construction Machinery" There are no visible residues on the metal surface. ### 3. Homework Data Recording The filling of the "Pressure Sealing Operation Report" should include: Pressure containment, duration Medium type and temperature Equipment Abnormality Record Photo of the worn condition of the sealing piece ## 2. Special Maintenance of Key Components #### 1. Head Blocking Maintenance | Component | Inspection Points | Maintenance Methods | |---------------|---------------------------|---------------------------|| Sealing element | Lip crack / permanent deformation | Measured compression amount (should be less than 10% of original thickness) | | Support Ring | Depth of surface scratches (≤ 0.2mm) | Measure with a micrometer | | Connection thread | Thread integrity | Apply molybdenum disulfide anti-rust grease | | Hydraulic cylinder | Erosion of the piston rod coating | Replacement of the sealing kit | #### 2. Maintenance of Hydraulic System - **Fuel Tank Handling** Empty out the old oil (using a vacuum oil extractor) Rinse the system with new oil (ISO VG46 hydraulic oil) Replace the oil filter (with a precision of 10 microns) - **Pipeline Inspection** Record of the usage frequency of the high-pressure hose (replacement required after more than 2000 uses) Measure the wall thickness of the steel pipe (using an ultrasonic thickness gauge) #### 3. Control Unit Maintenance Electrical interface waterproof treatment (IP65 protection level) - PLC Controller: