I am not an engineer or piping system designer but a field technician employed with an oil pipeline. What I am trying to do however is find out if there is any history with using an accumulator for thermal expansion on crude oil pipeline meter manifolds. This is in lieu of relief valves piped to a sump tank. Some conditions would include a 150 or 300# ansi pipe rating. A when isolated system volume of approx. 50 barrels. An ambient temperature rise of 30 degrees C. I would guess the size of accumulator needed would be somewhere around 5 - 10 gallons.
I am wondering if anyone out there has had experience with this type of an application and whether it is feasable. I think it would simplify things however am having a tough time selling the concept within our company. What may be some concerns over the present relief to sump arrangement?

I would think the main one would be that the accumulator would have to be precharged to 150 to 300 PSI which means pressure would have to go above that pressure at an increasing rate to absorb added volume. That is if it is a Gas Loaded type.

A Weight Loaded Accumulator could possibly be used since it would be designed with enough weight to stay empty until pressure increased some amount above what it would take to raise the weight. Safety wise you would still need the relief system in case of lack of volume or any other reason the stored oil did not discharge when pressure dropped back to normal.

If you are not familiar with different Accumulator designs you can see an explanation in the Basic Ebook at the home page of this Forun. Look in Chapter 16.