1/8" NPT Port Diameter

In reference to “R77 C. Solenoid valves with a maximum 1/8 in. NPT port diameter”

NPT - stands for Nation Pipe Thread Taper correct? Which is 27 threads per inch. How do we measure the port diameter? Isn’t port diameter different than say orifice size?

Is there a schematic that lays out the terminology?

What we are really looking for is to first follow the rule and second get the least resistance to make maximum use of the 60 psi. We have a variety of solenoids from past years and are doing our best to become experts, we seem stuck here for the moment.

Thank you!

In general, NPT threads are sized so that they can be cut onto the ends of NPS (Nominal Pipe Size) pipe. Thus, 3 NPT threads fit 3 NPS pipe, 1/4 NPT threads fit 1/4 NPS pipe, and so on. These threads are tapered so that male and female parts will wedge together, creating a relatively large sealing surface compared to the size of the parts.

It’s important to realize that the Nominal Pipe Size has almost nothing to do with an actual dimension of the pipe (especially in the small sizes). The OD of 1/8 NPS pipe is actually .405 OD.

The orifice size of your solenoid valve is an internal characteristic that is closely related to the valve’s Cv.

Thank you that was what we needed.