[tomj76]

The discharge line should be at a low pressure. I can't think of any normal conditions that would cause it to exceed 100 psi.

I've read that the accumulator can become blocked due to water vapor in the system. Since the accumlator is located downstream from the evaporator, a blockage might cause the pressure on the return line to increase to a high pressure, maybe even high enough to cause a hose failure.

I'm not sure what role the expansion valve and orphice will play in determining the ultimate pressure possible at this point. I'd think you'd notice some degrading of the a/c cooling capacity before a catastrophic failure like this one occured.

I would replace the accumulator at the same time as replacing the hose, just to be sure that no free water can cause problems in the system. When you have it charged (or do it on your own if you can get a vacuum pump) the pressures can be monitored to make sure they are in the proper operating range.