Dear memebrs:

We do an analysis of Water refrigerator - steam line for a temperature of 455°F pipe material carbon steel. In which the nozzle load for 8” flange is +676 lb at node 630 and +192 lb at node 970 which is less than the allowable load 787 lb but the force acts in the +Y direction.

But the doubt is, as per COADE Pipe stress analysis Seminar notes, Chapter-2 page 2-19, section 2.2.3-Consideration of Nozzle loads – It is specified that for a nozzle load in +Y direction (237 lb) seems to be unnatural for a gravity load and therefore it is not an optimally supported system. By re-analyzing the piping system the nozzle load has been changed to –Y direction (-495 lb) and it seems to be accepted compared to the above case even if the magnitude of the force is increased.

Why is it so? Can someone clarify this?

The same kind of situation occurs in our case as specified in first paragraph. The above discussed details are attached with this topic.

If the nozzle load must or (for optimal system) always be in the –Y direction, the following are the queries of the same,

1.Usually the allowable nozzle loads provided by the vendor is for both the +/- directions, so that the nozzle load in the +Y direction shall be accepted and the piping support system shall said to be optimal. If not please clarify.

2.But our Contractor says that if the actual value of nozzle load is within the allowable value then we need not to consider the directions. Is his suggestion is accepted?