Six years ago David Reeves and I started looking into a better way we could work with valve and packing manufactures to improve packings and improve the performance of packing in production valves. David was already working with the packing manufactures to improve braided packing and was requiring every new valve, regardless of size, to be repacked with rope packing in one of our California refineries. At that same time, our other California refinery was averaging thirty leaks per week where emission rates exceeded 100 ppm. Of those thirty leaks per week discovered by the fugitive emissions monitoring group, typically twenty eight valves could have packing leakages reduced below 100 ppm by retightening the packing gland bolts. This practice caused problems with the plant operators who found it difficult to open or close valves because the packing was too tight. An average of two valves per week went on a five day time clock to reduce emissions below 100 ppm to avoid an environmental violation. These valves required drilling, injecting, tagging to be replaced at the next maintenance turnaround, and replacing. The average cost to perform all this work was $2000US per valve.
There had to be a better way so we devised a packing test to emulate a typical process plant that starts up and shuts down causing the valve to go through large temperature swings. At that time, emissions tests performed by valve manufacturers were tested at a constant temperature. The results from our testing allowed us to eliminate the repacking of new valves and our fugitive emissions monitoring group rarely finds a valve leaking above 100 ppm. Our leak sealing of valves has reduced from almost 100 valves per year in one facility to less than five and we are headed to zero
We are encouraging valve manufactures to test their valves to API 622 and to use the packing material that performs best in their valves as their standard OEM packing.
The side benefit to us is we are now using fugitive emission tested valves in non-VOC severe service applications where we have traditionally specified bellows seal valves and grease seal valves. The cost savings and reduced lead times for standard valves verses grease/bellows seal valves are benefiting our capital projects.