Internal lining of Steel gate valve

[CoCoE]

"The body of steel gate valve shall not be internally coated unless the wedge is rubber-lined." This is a requirement from one of the company. My question is that, what my be the reason for such a statement? Is it due to the risk of impediment of the valve operation or something else? The line is totally internally lined.!! Anticipating your expert views.

 

[GameJudge]

My thought is that the concern is wearing of the lining where the wedge contacts the body. A rubber-lined wedge would mitigate this.

 

[CoCoE]

I understtod your point!! But is it better not to line internally, than getting damaged? What do you think on this?

In this particular sentence, the requirement is provided for coating, that "shall not be internally coated". If the sentence is like this " For steel gate valves, the wedges shall be rubber lined, if the body of steel gate vale is to be internally lined", there wouldn't have any confusion.

Regards

 

[GameJudge]

I read the original requirement and your revision the as the same requirement. Lined valves demand rubber-lined wedges.

If you need a lined valve due to process requirements, that valve will require a rubber-lined wedge. If steel will not withstand the process conditions, do not use unlined steel for the valves. If rubber will not withstand your process conditions, you may need to look into exotic materials of construction.