Safety Talk 17 / 24 Flare valve removal Install flare valves 'upside-down' Survey flare line topography for low points Initial break near drain valves
{"Image DocumentName": "Flare valve removal Install flare valves \u2018upside-down\u2019", "Image ImageDescription": "Survey flare line topography for low points. Initial break near drain valves. Spade isolation. Investigate use of hydraulic devices to split flanges remotely. Venting points to inject inert gas. Nitrogen purging and wetting of work surfaces. Location and protection of machinery. More senior staff involvement / written procedure. Carry out work only when refinery is steady, and allow no process changes during work. Fire during valve removal (slides 23 and 24) A flare main valve located some 20ft above ground level was being removed by contractors working on a temporary platform. The section of the flare main had been valve isolated. As the flanged joints were being broken there was a substantial release of hydrocarbon liquid, which vaporised to form a gas cloud. This ignited and in the subsequent fierce fire two of the men died and a further two suffered serious burns. The fire continued to burn for some 40 hours and was only extinguished by shutting down all the process units and injecting nitrogen into the flare system. The liquid had passed through closed valves. The flare line sloped away from the flare KO drum to the job-site, and the test to check for liquid in the line was not carried out at a low point. The source of ignition was probably a mobile air compressor, whose exhaust spark arrestor was missing. (The compressor was originally sited close to the job-site, but the Plant Supervisor had it moved some 35ft (11 metres) away). All the block valves were passing, partly due to sludge preventing the gates sealing properly. Installing valves \u2018upside-down\u2019 would help avoid this problem. Tell-tale devices to be fitted to all major flare valves to give indication of valve closure. More senior members of the Refinery Staff should have been involved and a written procedure prepared. High risk work on flare systems will be done only when refinery operation is steady and flare status is satisfactory. No unit changes will be made whilst flare work is in progress. Venting points have been provided to allow inert gas to be injected into the flare main. Consideration will be given to necessity for nitrogen purging of pipework and wetting of work area surfaces. Survey of flare line slopes (topography) will be made. Work site to be spaded off prior to commencement of work. Initial breaking of joints should take place at points near drain valves. Refinery will investigate the use of hydraulic devices for splitting flanges from a remote location.", "Image XResolution": "37", "Image YResolution": "37", "Image ResolutionUnit": "Pixels/Centimeter", "Image Software": "SlidePlayer", "Image YCbCrPositioning": "Centered"}