Basic question: Can I connect 300# nozzle with a 150# line?

these people are making it more complicated than it is. It's Very simple.
Connect a 300 rating flange to the 300 rating nozzle. Then weld 150 rating pipe to the 300 rating flange. If the schedules don't match, change the schedule of the 300 rating flange to be the same as the schedule of the pipe (why? becuase the schedules of a weld should match on both sides of the weld for welding easablitiy).

Then weld 150 rating pipe to the 300 rating flange.
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becuase the schedules of a weld should match on both sides of the weld for welding easablitiy).


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Hi everybody.
Let me try to solve. I have 3 methods to solve

1. Find flange 300# with same schedule as pipe
2. Tapped 1:3 on flange 300# until same thickness as pipe
3. use flange adaptor (150# - 300#)

thank

Let me try this..
1. 150# and 300# flanges can not be connected together due to difference in PCD's.
2. Normaly in PN 150 class we can have a higher rating flange i.e. PN 300 flange in PN 150 pipe class.
3. Now the question arises is of welding it can be done in following way.
Trim the schedule of PN 300 flange to match with the PN 150 Pipe schedule and weld it.

Wow......complicated answers to a simple question. It did get answered in amongst those posts, then it got weird so I will clarify.

Basically because the tank is a higher rating (300#) than the piping system (150#) this is an easy fix. The flange rating needs to match the nozzle.....so 300#. The 300# flange wall thickness/schedule needs to match the piping schedule as specified by the 150# spec. So simply if your piping is sch. 80 you would require a 300# sch.80 flange at the nozzle. Not to confused you but, technically you are creating a spec break at the weld between the flange and the pipe but, because its just at the flange a spec break isn't required. Its built as part of your 150# piping spool with an odd ball flange. Hopefully that makes sense.

Now if that tank had 150# nozzles and your piping system was 300# then the above doesn't apply. You can't run a higher rated system into a lower rated tank. You would then need ask questions.