I need to purchase needle valves for Instruments isolation purpose. It is meant to be at stock as a replacement for built-in Y Pattern needle valves.
But I hesitate whether to buy it in normal shape or in that Y Pattern shape.
What is the idea of Y-Pattern needle valves? When I need them?
Normally, I can state PN, DN, Material and operating temperature regardless of the valve shape, but I'm afraid to be missing a critical point about that Y Pattern.
Also if you can refer to me other important points to consider while purchasing those valves, that would be great!
If the valve is part of the instrument, you need to consult the supplier literature. If a shut-off isolation valve, those are larger.
Supplying the instrument model number would be helpful for your responses.
>specific model or supplier.
Maybe the original is Y-style for operating handle clearance? No way to tell because my crystal ball is cloudy.
I know that I've seen Y style needle valves that are fully roddable, for situations that require such, but other styles can be fully roddable also.
the term "Y pattern" is certainly not in common usage, so you need to better identify the valve you are replacing.
Google is your friend.
A simple search for "reason for a y pattern needle valve" found this;
Wye Pattern Globe valves design, is an alternative for the high pressure drop, inherent in Globe valves. Seat and stem are angled at approximately 45°rees, what gives a straighter flowpath at full opening and offer the least resistance to flow. They can be cracked open for long periods without severe erosion. They are extensively used for throttling during seasonal or startup operations. They can be rod through to remove debris when used in drain lines that are normally closed.
Seems like a concise summary.