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How to convert PPMw (by weight) to PPMv(Volume) for H2S & moisture(H2O) in gas mixture?
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Submitted Chris Haslego, Nov 21 2011 11:21 AM | Last updated Nov 21 2011 01:29 PM

Category:	Plant Basics
Question:	Is there any way to repair a valve that is passing (leaking internally) without taking our process offline?
Keywords:	on,line,valve,repair,leak,passing,internal,leakage,repair
Answer:	BACKGROUNDA 600 psig, 3" steam line is experiencing "passing" or internal leakage. If order to replace the valve, the process would have to be taken offline. A temporary solution to the problem is sought to get the plant to their next scheduled shut downANSWERResearch on-stream leak sealing services. This problem is quite common. What they would do in this case is drill a hole into the bypass valve on the upstream side but not completely into the line. They would then tap the hole and install one of your injection fittings which is like a small plug valve. They would then take a long 1/8" drill bit and drill through the open injection fitting and into the pressurised line. The drill bit is then removed and our injection equipment is then attached. Sealant (heavy fibres and grease) is pumped into the line and caught in the flow which will bind up against the leaking seat on the bypass valve. If done properly, this technique can be both effective and safe.
Links:	Eveready Industrial