{"id":1406,"date":"2021-10-13T02:01:00","date_gmt":"2021-10-13T00:01:00","guid":{"rendered":"https:\/\/as-schneider.blog\/?p=1406"},"modified":"2021-10-15T11:53:58","modified_gmt":"2021-10-15T09:53:58","slug":"4-most-important-mechanical-isolation-methods-of-mechanical-equipment","status":"publish","type":"post","link":"https:\/\/as-schneider.blog\/2021\/10\/13\/4-most-important-mechanical-isolation-methods-of-mechanical-equipment\/","title":{"rendered":"4 most important mechanical isolation methods of process piping & equipment"},"content":{"rendered":"\t\t
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4 most important mechanical isolation methods of process piping & equipment\n\n<\/h1>\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t\t<\/div>\n\t\t<\/div>\n\t\t\t\t\t<\/div>\n\t\t<\/section>\n\t\t\t\t
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Positive isolation of process piping, equipment, or vessels<\/h2>\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t
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Positive isolation is the isolation of process piping, equipment, or vessels from hazardous materials such that it is impossible for the material to enter the work area. Positive isolation must remove all risk of accidental reconnection to the source of the hazard due to equipment failure or operator error. There are several methods of achieving positive isolation some of which are discussed below.<\/p>\t\t\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t\t<\/div>\n\t\t<\/div>\n\t\t\t\t\t<\/div>\n\t\t<\/section>\n\t\t\t\t

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4 most important mechanical isolation methods<\/h2>\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t
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Spool removal or air gapping isolation <\/h3>\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t
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Spool removal or air gapping is a line-breaking method that involves removing a spool section from the piping and installing a blind flange to block the flow from the source. This method is highly reliable and secure as it achieves actual, physical separation of the source from the equipment. The downside of this method is that if the pipeline has a large nominal size, the spool can be very bulky to disconnect, remove, and replace after the maintenance work. Lifting equipment and additional manpower are required to achieve isolation. Furthermore, maintenance workers may have to deal with rusted bolts and misaligned gaskets extending the downtime as flange surfaces are cleaned and a new gasket is inserted. This isolation method is very time-consuming and is not suitable for routine maintenance work and emergency situations.<\/p>\t\t\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t

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Blind isolation<\/h3>\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t
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Blind isolation refers to the insertion of a blind (spade) between two flanges. In installations where spool removal is difficult to implement, isolation by a valve and line-rated spade provides the next highest level of security. The blind may be inserted by replacing a spacer ring with a line blind or rotating the blind end of a spectacle blind into place that has been installed on the flange. A spectacle blind is a permanent installation designed to simplify the change-over between a blind and an open-spacer. Blind isolation still requires physical labor and manual intervention consuming manpower, resources and time, especially with large bore piping systems. Maintenance workers may still encounter problems like rusted bolts or a damaged gasket that must be replaced. The blind portion of a spectacle blind often gets corroded and may need to be scraped and cleaned before it can be used. Spool removal and blind isolation are generally recommended for situations where isolation is expected to last longer than a month.<\/p>\t\t\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t

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Single valve isolation<\/h3>\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t
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As the name suggests, single valve isolation uses only one valve to isolate the source from the work area. The isolation is critically dependent upon the reliability of the seal and the integrity of the single valve operating stem. Such a system may only be used for the purpose of swinging a spectacle blind, inserting a line spade or fitting a blind flange to achieve higher integrity isolation. Single valve isolations may only be considered for routine, short duration, low pressure, cold work.<\/p>\t\t\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t

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Double block & bleed isolation<\/h3>\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t
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A Double block and bleed (DBB) isolation system is considered to be the most secure form of valve isolation. It consists of two valves in series, with a bleed valve in between, that allows the pressure\/material, between the two valves, to be bled through a vent directed to a safe location. To achieve isolation, the two main valves are closed and the bleed valve is opened. The DBB configuration shuts down a section of the pipe on both sides rather than just one. Double block and bleed isolation reduces the risk of harm to people and the environment. It is considered to be the minimum sole means of isolation for cold routine short duration work at moderate to high pressures.<\/p>

Complex work processes, combined with tight maintenance windows, present a challenge for installation and maintenance personnel in the oil & gas sector and other industries. Many companies have adopted the policy of mandatory DBB isolation when maintenance work is being performed on field equipment. A DBB installation can reduce the maintenance and installation effort considerably while providing a process safety solution for positive isolation on both sides. In addition to simplifying maintenance, DBB systems are also useful in:<\/p>\t\t\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t

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