I can't find the information that I need in the product description.

Miniature chrome-plated brass ball-valve, part # 4912K77, with 1/4 NPT female ports, from:

http://www.mcmaster.com

My question is, considering that the 1/4 NPT female threaded hole is of larger diameter than 3/8 ID hose, will this valve flow 3/8 I.D. all the way through, or will it be a restriction.

If it won't carry 3/8, which NPT size miniature ball-valve will??

Thanks.

 

1/4" measures 5/16" ID and 3/8" measrues 7/16" ID so a 1/4" will probably give you some restriction. I would go with 3/8"

 

You can't tell without either looking through the valve or by seeing the description where it says "Full Flow". Manny cheaper ball valves, or older ones, have a smaller hole in the ball than the inside diameter of the pipe that screws into them. As long as it's not way smaller, or you are right at your flow limit and can't stand a little more restriction, it's not much of a problem. But full flow valves are always better and I look through every type I get just to see.


John

 

Try looking for "full bore" ball valves where they have purposely oversized the casing for the ball ID to be the same as the piping.

 

what are you trying to do?

3/8 is an uncommon size. either go 1/2 or 1/4. If a 1/4" valve is a problem, your undersized at 3/8"

 

I think he's referring to the actual measured size of the hole, not the pipe size.

John

 

Yea, the restriction in a ball valve is so small and so short that if 1/8" diameter is going to matter in the system, then 10 feet of 3/8" hose is going to have more restriction than the one valve.

 

If full bore or full flow does not turn up much, try full port. I believe that is the proper term used.