What is the maximum maintenance interval you would recommend for pilot operated relief valves in clean butane service?
API RP 576 provides interval guidelines with 10 years as the maximum. This may be okay for conventional spring loaded RV's but seems excessive for pilot operated RV's that are...
"TYP." usually means that the dimension is typical of other locations on the drawing. This will reduce the clutter of redundant dimensions on the drawing but may add to confusion if not used properly.
