what is the standard for female npt depth?
what is the standard for female npt depth?
(OP)
say i need a 1/2" npt in a valve body. this will be used to feed hydraulic fluid into the valve.
the material i'm tapping is 1" thk. from machinery's handbook, 1/2" npt has effective ext thread length of .5337, yet an engineer says to drill/tap thru.
isn't that rather illogical? how deep is too deep? hand-tight engagement is only .32. running the nipple in will gouge up and destroy the first threads, won't it?
i appreciate any replies.
peace..out. tk369
the material i'm tapping is 1" thk. from machinery's handbook, 1/2" npt has effective ext thread length of .5337, yet an engineer says to drill/tap thru.
isn't that rather illogical? how deep is too deep? hand-tight engagement is only .32. running the nipple in will gouge up and destroy the first threads, won't it?
i appreciate any replies.
peace..out. tk369





RE: what is the standard for female npt depth?
thread1103-216997: Specifying female 1/16-27 NPT on drawing.
KENAT, probably the least qualified checker you'll ever meet...
RE: what is the standard for female npt depth?
For those familiar with Eugene Megyesy's "Pressure Vessel Handbook", there is a nice table in there on "Length of pipe engagement to make a tight joint". For a 1/2" nipple it gives 1/2" engagement to make a tight joint. Megyesy's table is just a little less than L1+L3 for all pipe sizes, and I have found it to be accurate so I use it to calculate pipe lengths needed.
RE: what is the standard for female npt depth?
RE: what is the standard for female npt depth?
Matt Lorono
CAD Engineer/ECN Analyst
Silicon Valley, CA
Lorono's SolidWorks Resources
Co-moderator of Solidworks Yahoo! Group
and Mechnical.Engineering Yahoo! Group
RE: what is the standard for female npt depth?
3 or 4 threads at 1/2" NPT - 14 pitch is only .21-.29" and that is probably not going to seal.
RE: what is the standard for female npt depth?
RE: what is the standard for female npt depth?
Matt Lorono
CAD Engineer/ECN Analyst
Silicon Valley, CA
Lorono's SolidWorks Resources
Co-moderator of Solidworks Yahoo! Group
and Mechnical.Engineering Yahoo! Group
RE: what is the standard for female npt depth?
Additional point, over tightening can cause deformation of that threads that reduces the NPT's ability to seal on subsequent engagements.
Matt Lorono
CAD Engineer/ECN Analyst
Silicon Valley, CA
Lorono's SolidWorks Resources
Co-moderator of Solidworks Yahoo! Group
and Mechnical.Engineering Yahoo! Group