pitches to mechanize a 900 mm pipe with square thread

[NavalArchitec]

Hello friends,
I would like to know where I can consult the different possible pitches to mechanize externally a 900 mm pipe with square thread. I only find pitches for screws and always tells that the pitch = 0.2 x diameter of the screw. But this is too much because a pitch of 0.2 x 900 = 180 mm!!.
Thank you,

 

[EdStainless]

Why a thread on 35" pipe?
And why square (I hope that you mean Acme or buttress)
The thread pitch becomes a smaller percentage of the diameter as the thread gets larger.
For example 12NPT is 8tpi.

= = = = = = = = = = = = = = = = = = = =
P.E. Metallurgy, Plymouth Tube

 

[drawoh]

... pitch = 0.2 x diameter of the screw

I have never heard this rule. Aside from standard pipe threads, the pitch is whatever you tell your machinist to do. Look in the Machinery's Handbook.

What do you mean by "mechanizing" a pipe? Are you designing an actuator to move it?

--
JHG

 

[blacksmith37]

You will find a variety of large diameter thread profiles in OCTG ( oil country tubular goods); both API and proprietary. Vetco was a main vendor, I expect they have a site with some info.

 

[NavalArchitec]

Thanks!