Document oRq4qMO5mBEQ2vbwK6e0qYqo

(y Interoffice Com munication to J. C. Ledvina - Houston From J. A. DeBerna rdi Date June 15, 1981 Subiect Proposed Fugi tive Emission Standard D Jo '0/ The following are my omments related to your letter of June 5 on the subject. If a time requirement on rupture disk replacement after failure is part of this standard more than five days should be requested to overcome unforeseen circumstances such as rupture disk availability or need for special equipment (perhaps a c rane) to affect the changeout. The overall problem th at is being missed by this regulation is the fact that it is being assun ed that the rupture disk failure is caused by overpressure that breaks he disk and lifts the relief valve. In fact, rupture disks fail prematurely more often than from overpressure. Pressure cycles, corrosive materials, tc. account for these failures by far more often than equipment overpressure We have been, and I as sume will continue to be, successful in using block valves under relief ve Ives in our plant. Proper procedures can, and are, set-up to assure that block valves are open and remain that way in our plant and many others In a potentially corrosi ve process environment, use of rupture disks withe ut block valves in relief valve service will adversely affect stream factor Ijhereby reducing productivi ty and increasing operating costs for the process It is my opinion that th is standard will increase fugitive emissions to the atmosphere from proces s start-ups and shutdowns which it has the poter tial to cause. The overal 1 impact on the environment will be exactly opposi te of the intent. It is our plant's inte nt to continue the use of block valves in relief service, This is not a safety ssue when proper procedures are established and followed With this assumption, and barring any unforeseen circumstances, rupture disk replacement should be possible within a five day period. J. A. DeBernardi br CC w/o attachment GCB-GJF-MGH-BR CC w/attachment RDG VVC 000013355