Category E is specifically for expansion joints, flexible connections, and hose assemblies.
Category H is a generic hodge-podge for itmes that do not fit into Categories A - G. Category H may include a series of components (including piping components) joined together to form a single fitting, provided that the diameter of any component does not exceed 152mm (6") and the total volume of the fitting does not exceed 42.5L (1.5 cu.ft).
All above taken from B51-03, Table 1. Refer to this table for a description of all other categories.
thanks chaulklate, the typical problems usually don't originate on big vessels but the small vessels are tricky. Sometimes it gets forgotten to register those since they are so small. I have been beating this drum forever.
:
For those that cannot read B51.
Category E are strainers, filters, seperators, and steam traps. So do all 2 and 3 phase seperators fall under category E fittings or as pressure vessels. What if my steam trap in 4" and < 1.5 cuft? What about my seperator that is 6" and > 1.5 cuft. According to the flow charts, there are only pressure vessels and Category H fittings. What about minature pressure vessels? They are inspected by the manufacturer and < than 1.5 cuft but > 5 cuft. It is not even addressed in the flow charts, but they exist.
