crooked valve? justified or... 1

[Danlap]

Good day fellow valve practitioners,

We've ordered 2"-600# butt welded gate valves, and received as follow condition (in my opinion is crooked)

Is this even allowed or acceptable practice?
Reason from manufacturer is as follow
quote "This configuration is used on smaller valves to facilitate the seat pocket machining which is roughly perpendicular to the waterway" unquote

In some occasion, flow is erosive enough, then the 'hilly' part might be eroded sooner. It is possible but not desirable to adjust the counter butt weld (on piping side) to mount this valve. And also sometimes we use this for hot tapping, meaning straight passage is a MUST.

Looking forward for the constructive feedback.

Thank you in advance,
Kind regards,
D

 

[LittleInch]

Rather strange alright and I guess the end butt weld connection at an angle makes it a a "mitre" bend, which above 3 degrees is often not allowed in piping design.

What general spec did you order to? API?? ASME?? or a company spec?

What does it say?

Strange how everyone else seem to manage OK....

Remember - More details = better answers
Also: If you get a response it's polite to respond to it.

 

[alchemon]

What is the material of the hilly part you are worried about and fluid going through it?

 

[gerhardl]

Seems from the picture that some of the valves are straigt through and some at an angle? Or are all angeled? Seems also that the valves are cast, and in the angeled form, not as a cast- form fault. If this is a planned form, the producer should have a reasonable explanaition. Please tell us, never seen anything like it.

 

[Danlap]

Good day all,

Some short update, please find below drawing from two of our suppliers (well known companies with initial V and also K). But not limited to other suppliers as well, as far as I know.
fyi: my valve material is WC6, but it seems applicable for all material.
Their arguments are manufacturing best practices and easier for (seat) machining access.

have a short discussion with my principal (I am end user), we do not see any stress related issues. Also we dont need to adjust our piping connection.
Cannot find any valve standard referring to bore straightness as well.

Personally I am still bothered with this (vague explanation), but I have make peace with it .

Hope this information helpful for other people.

Regards,
D

 

[reverman]

This is fairly common on small gate valves typically 1" and below sizes flanged/buttweld ends because machining the seating area can be difficult without inclining the waterway due to long end to end if you order same valve with SW or THD ends you likely won't see this . By 2" size typically waterway is big enough to get tooling through it without needing to do this but in the end I don't think it should be an issue.