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lug butterfly valve piping replacement

lug butterfly valve piping replacement

lug butterfly valve piping replacement

Hey Guys,

I am currently working on a project where i need to replace entire piping with valves.

The configuration is as follows.

Blind flange>>Piping section>>Lug butterfly valve>>piping section>>Blind flange

Problem statement :
Since lug butterfly valves have single through bolts, while replacing these valves and installing new ones, i need to keep disturbing the adjacent piping section also beacause of the the through bolt.

Is there any idea to replace the valves without disturbing the adjacent section?
Your response will be highly useful.

RE: lug butterfly valve piping replacement

Consider a double flange BFV.

Per ISO, only the term Safety Valve is used regardless of application or design.

RE: lug butterfly valve piping replacement

Your butterfly valve type sounds like a "wafer" type valve with the bolt going through the bolting holes.
The correct "lug" type valve is that the valve can be unbolted either end independently. You may check with the valve vendor for the correct "lug" valve type or change it with the double flanged butterfly valve as suggested above.

RE: lug butterfly valve piping replacement

the problem exists only with WAFER type butterfly valves, which have to be installed inbetween flanges (like a gasket).
LUG type butterflies have through threaded holes (except the ones adjacent to the stem which are blind holed) which means you can bolt either end independently.

RE: lug butterfly valve piping replacement

1. Yes, there is always a solution.

2. It will help with a drawing and a bit more detailed description of 'lugs'

3. Reason: 'lugs' have been misused and used with different meanings from different factories throughout the world and, covers threaded lugs, open lugs for holding, a mixture of both types on the same valve, and others. This regardless all tries for standardization.

4. Most economical solution will be depending on exact details of all connected pieces, nominal sizes, pressure class and number of valves (plus of course all other engineering and flow details. Solution could be other types of piping/connection pieces/valves or special bolts and flanges.

Good luck

RE: lug butterfly valve piping replacement

Alfred Philips,
how long are the piping sections?

Some Manufacturers may supply double-flanged triple-offset valves with extended, even customized, face-to-face dimensions (usually intended to replace existing gate valves): perhaps they may replace your "Piping section>>Lug butterfly valve>>piping section" as a whole, or partially...?

Hope this helps,

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