Leak repair clamp

The leak repair clamp was a good idea, but it was one of those jobs that was easier said than done. There was minimal supervision when the crew returned on Saturday and took it upon themselves to build a steel box around the leaking valve. 

Frequent use of leak repair clamps to externally stop process fluid leaks raises questions about the efifctiveness of a mechanical integrity program.... Be sure that temporary repairs are managed so they can be includedfor permanent repair when planning the next shutdown. 

Due to the crack nature of the defect and to prevent expansion/bulging and failure of the pipe on either side of the leak repair clamp, it was recommended to install within 1 m on either side of the clamp 12-in. crack arrestors. This will not prevent the pipe from continuing to crack, but if it does it will prevent rupture. It is very important that this region of the pipe is restrained as it will greatly help the complete function of the total repair (Lesmana, 2011) (Figure 6.20). 

In todays world, many U.S. chemical plants rely on specialty leak repair contractors to stop steam and other utility fluid nuisance leaks. However, in the mid-1970s these contractors were not immediately available to many plant sites, so the plants had to create their own clamps or other containment systems if shutdowns were to be avoided. 

A well accepted method of repair involving an external fixture is the utilization of mechanical clamps (also known as sleeves) to encase the damaged region. These can be applied for both leak containment and strengthening (Coley and Caraballo, 2011). The clamps arc typically metallic and consist of two-piece flanged shells with oversized annuli that fit over the pipe, with perimeter elastomeric seals for fluid containment. The clamps are fixed together via a series of bolts on the flanges. For underwater applications, they are normally fitted with aluminium anode blocks for cathodic protection. 

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