"DannyD." wrote in message
...
Tekkie® wrote, on Sun, 06 Jul 2014 13:16:23 -0400:

This is true. Back in my ff days we had boards with the different
adapters
used. It all depended on which the water company used. Sometimes even
the
fire truck manufacturers would have their own threads!

This local Santa Clara County government PDF says all the wharf hydrants
have to have the same threads (which makes sense):
http://www.sccgov.org/sites/fmo/docs...Hyd-070910.pdf

Wharf Hydrants are residential type fire hydrants with a single two
and one-half-inch (2-1/2-inch) outlet and a control valve (operated by a
pentagon nut with no handle), typically supplied from an on-site tank or
Shared Water System. (See Figure 1)

Hose threads for all hydrants shall meet National Standard Thread (NST)
requirements. Piping and appurtenances shall be a minimum diameter of
4-inches.

It's interesting to see in the diagram in that PDF the buried "thrust
block".

I had never seen a thrust block before ... have you?


seen them and poured them. Do the math.