Document mm8G5Lz5YBd4gV0G1D4BJ0Y54

A OSS-3 A Issues Hazard Alert in Wake of Amoco Explosion To prevent further tragedies like the October, 1980 fire and explosion at the Amoco, New Castle Delaware polypropy lene plant which leveled the plant, killed six people and injured 28 others, the OSHA Philadelphia Regional Office sent out a hazard alert to OSHA compliance officers and others in the chemical process and oil industries.- d The alert addresses the underlying cause of the Amcco explosion --failure to train craftsmen that removing attachments to block valves will cause the valve itself to fall apart as the attachments--in this case a pneumatic controller -- are an integral part of the valve as shown in the sketch on this page. The following is excerpted from the Alert sent out by OSHA Regional Administrator David Rhone. It should be studied carefully by ail OCAW members in the oil and chemical process industries. "The employers' responsibilities with regard to this hazard include but are not necessarily limited to the following items". 1. Mechanics or operators whose job it is to assemble, adjust or disassemble valves or attac hments to valves shall be trained in the safe assembly, disassembly, or adjustment of each type of valveattachment assembly. OCAW HEALTH AND SAFETY NEWS Vol. a, Nos. 1,2 April 1981 Published in cooperation with the OCAW Union News, 1636 Champa St., Denver, Colo. 80202. E. J. Kousselle, Vice President Anthony Vmocclii Director, Health and Safety Dept, SyKia Krcktl Occupational Health Spzd Kofa:l M'/Utc Industrial Hygienist Stove W'xfko, Inti. fffprpt'flMiiw I ;*m> of interest for lire May issue L v Apr if 70. Sdbtcnptien price for non-members is ?5 per yter. i 1l 1 Hnj"1. Vi rif i K-; tr i i^r. i H -s i O" r- - . . 'Ll ' I'l CHEMICAL PROCESS AND OIL INDUSTRY CONTROLLER-PLUG VALVE ASSEMBLY SCHEMATIC 1 Mechanics or operators who have not been so trained shall not be assigned to perform such duties without supervision by those foremen or operators who have been trained. 3. Attachments to valves which regulate hazardous materials shall not be con nected to the valves with the same bolts which preserve the integrity of the valve, without assurance that such attachments would not be removed while the valve is in service. Background: A recent investigation of an explosion and fire at a chemical plant revealed that when workers removed the pneumatic controller from a block valve, the valve itself fell apart. The reason for this was that the bracket which connected the controller to the valve was attached to the valve with the same four bolts which held the bonnet of the valve to the body (sec sketch). On October 21, 1930 four mechanics were assigned to perform a slurry linecleanout for a ten thousand gallon polypropylene reactor. The slurry line ran from the bottom of the reactor through a pump, a slurry cooler (heat exchanger) and then back to the top of the reactor through a four inch line. The s*urry line lind been isolated from the system by the closing of the two block valves, one at the top and one at the bottom of the reactor. Each block valve had a pneumatic controller attached but the connecting mechanisms were different. The valve at the top was a ping valve. The controller was attached to a bracket which was in turn ' i "T 1 : I - i |i -- attached to the valve bonnet by the same bolts which held the bonnet in place. The valve at the bottom was a ball valve. Because of its configuration the same type of bracket connection could not be used. The controller on this valve was connected to a bracket which in turn was held in place by two large "U" bolts which attached around the top and bottom flanges of the valve. 4 The mechanics split into two groups. Two men began opening lines at the top of the reactor while the other two broke the lines at the bottom. They cleaned out the slurry lines and broke for dinner. When they returned they were asked by the chief operator to rodout the block valve at the top of the reactor. That valve still had the controller attached. The company operating procedure required that the controller be removed prior to the opening of any lines to determine the position of the valve, but since this had been overlooked, the mechanics decided to remove it even though the valve was obviously closed. It was at this juncture that the two mechanics made the fatal error. They removed the four bolts which attached the bracket to the valve. Those same four bulls held the valve together. Upon removal, the plug and bonnet shot out and contents of the reactor, ten thousand gallons of propylene and hexane at 150 psi, poured out through the four inch opening. An enormous gas cloud foVn^-698^n^l tlucc minutes an explosion occurred which could be heard over ten miles a wav. * ......... t [I 3ai// /feacfor Question No. 1: Most Important Safety Considerations What are some of the most important safety considerations that you would investigate to evaluate the overall plant safety status? Number of (a) Containment of vinyl chloride Replies 1. Relief valve and rupture disk system and condition 2. Emergency relief containment capacity and recovery system 3. Cooling and electrical backup for reactors 4. Reactor controls 5. Unloading and storage and handling of VCM 6. Reactor S/S system 7. Control of reactor bottom valve 8. Emergency shutdown systems 9. Agitator alarms 10. Reactor area manned at all times 11. Maintenance records for vessels in VCM service 12. Vessel integrity program (6) (3) (3) (2) (2) (2) (l) (l) (l) (l) (l) (l) A (b) Contingency - preventing fires and explosions in the event of V.C. escape 1. Fire protection system 2. Plant layout 3- Presence of safety equipment 4. Plant emergency plan 5. Electrical equipment properlygrounded 6. Use of fire safe valves 7. Ability to handle large quantities ofV.C. gas (6) (4) (2) (l) (1) (l) (l) (c) Good safety and operational management 1. Up to date procedures - complete operating manual - plant follows procedures 2. Training and education of all personnel 3. Maintenance status - P.M. program 4. Housekeeping 5. Attitude of management and personnel 6. Safety organization 7. Operator involvement in safety 8. Inspection system 9. Engineering standards - design criteria being followed 10. Proper raw material storage 11. Regular safety sessions 12. Inter-action between Production and Maintenance (ll) (10) (7) (6) (5) (2) (l) (l) (l) (l) (l) (l) (d) Indicators 1. Past Records - frequency and severity records 2. Monitoring and emission records 3. Most recent systems safety analysis review (4) (2) (1) t VAB.0001035212 r.. s . *.< .-h : - k .............. H'l. ,r >vL lu i|.|. m- -h irfeiutfr-- J"I!"|1W |*M - 't-in*-- i > r-i- i. i- .. .............................. ,| -k- I ii i Question Wo. 2: Reactor Discharge Valve Control How do you prevent the wrong reactor from being opened? 1. Operator training and procedures 2. Clear identification of reactors 3. Mechanical locking system - two people to open 4. Discharge port is covered with a locked cover 5. Fixed discharge piping - batch always contained 6. Reactor discharge valve interlocked with reactor pressure 7. Two valves 8. Software interlocks 9. Warning light system - indicates safe to open 10. Electrical interlocks 11. Communications 12. Pressure gauge mounted beside valve 13. Slow opening valves - time to discover mistake 14. Drop valve actuated from reactor top - hear pressure gauge and sight glass 15. Working on a locking device A Number of Replies (8) (6) (4) (4) (4) (3) (2) (2) (2) (l) (l) (l) (l) (1) (l) Question No. 3: Charge Volume Control How do you n water, VCM, catalyst, suspending agents? Water VCM Catalyst Suspending Agents Weight 0 7 9 8 Meter 15 10 0 2 Volume 1 1 3 1,, (b) How do you prevent over or under charging? 1. Visual checks on levels 2. Operator training, procedures, signing charge sheet 3. Calibrating meters - maintenance 4. No independent mechanism to prevent over/under charging 5. N/A 6. Dual meters 7. Computer controlled (c) How do you control charging sequence? 1. Operator training and procedures 2. Computer 3. Sequence controlled by mechanical stepper switch 4. N/A 5. No answer (7) (6) (3) (2) (2) (1) (1) (12) (3) (1) (2) (2) VAB.0001035213 * Question No. 4: Gasket Replacement Control (a) Do you replace gasket -- 1. After each opening Yes No No Answer 75 7 2. After major maintenance 15 0 k 3. Once per year 31 Ik M/A 1 1 2 Number of Replie s (b) Pressure of the pressure test -- 1. After each opening psig - 50, 200, 90, 30, Vacuum, 80$ of R/D rating, 15" Hg vacuum 2. After major maintenance psig - 100, 140, 150, 85, 120, 150, 135, 120, 180, 60, reaction pressure, rating - 10$ 3. Once per year psig - 170, 175? 180 (c) How often is a manway gasket re-used? 1. Inspected visually and re-used if passes inspection 2. Never re-used 3. 10-15 times k. 10-20 charges 5. 50 charges 6. 100 - 150 charges 7. No answer (8) (3) (3) (l) (l) (l) (2) 0-Rings 10 (d) Are your manway gaskets 0-rings or flat gaskets? Flat N/A 82 A Question No. 5 Safety Valve Control on Reactors d (a) How often do you inspect your safety valve nozzle? 1. Each time the reactor is entered or opened 2. After every charge 3. Approximately every 3 days 4. Once per week 5. Once per month 6. Once every 30 - 50 batches 7. Two parallel relief nozzles- each with 2 rupture discs and no pop safety valves 8. Do not use safety valves on reactors - use doublerupture discs 9. No answer r- 1: I . -H--h> (7) (4) (l) (l) (l) (l) (l) (l) (1+) VAB.0001035214 M 4 Question No. 5: Safety Valve Control on Reactors (t>) How often do you test your safety valves? 1. Once per year 2. Every 6 months 3. n/a Number of Replies (UO (i) (5) (c) Are safety valves removed and cleaned after each release? Yes 15 No 0 Yes was the only answer if the question was answered, except' -- "no reactor releases - should be done - no policy." A Question No. 6: Reaction Shortstop (a) Do you have a reaction shortstop system? Yes 17 No 2 N/A 1 Automatic Operator No answer (b) Is the injection automatic or done by an operator? 5 16 3 If automatic, what initiates the operation? -- Agitator RFM -- High reactor pressure -- Loss of power to agitators -- Over pressure or temperature or loss of agitation -- Loss of agitation, agitator motor, high water pressure, power failure V -,, .. r r -r|- t rt .............................................................. T - - |H - VAB.0001035215 P r- 1 MV Question No. 6: Reaction Shortstop (c) Is this system or a common sy Independent Common 10 6 Both systems 1 No answer 4 Number of Replies (d) How often was year? Less than 10 6 10 to 100 times 4 Over 100 times 4 N/A 6 times the shortstop system was used in non-emergency situations Daily Weekly Monthly Yearly N/A (e) How often was your system tested last year? 2 1 3 1 13 A Question No. 7: Reactor Pressure Control (a) How do you prevent pluggage in reactor oressure transmitters? .1. Water injection 2 Inspection and manual cleaning 3. Solvent cleaning system 4. Dual pressure systems N/A 6. Not a problem (6) (10) (1) (2) (1) (1) K1 . .1 t T'-fi l *1 . VAB.0001035216 b- x; . |-h^- -r jI- : . !J . % ; s i 's-Hr-JT"' 1 > - - Question No. 7: Reactor Pressure Control (b) Do you have alarms for high pressure? Yes 18 No answer 1 N/A 1 (c) Approximately what percent of normal operating pressure is the alarm set for? 1. Less than110% 2. Between 110 -120% 3. Over 120% U. No answer Question No. 8: VCM Pump Control What protection do you have to prevent remote operated VCM pumps from starting with suction and discharge valves closed? 1. Operator training, procedures, etc. 2. Automatic valves interlocked with pump 3. None 4. No answer 5. CRT display 6. No remote pumps Question No. 9: VCM Storage Tanks (a) Do you have sprinkler protection for your VCM storage tanks? Yes 20 ^ No 2 -- Use monitor nozzles on older installations. -- No, for some larger tanks Number of Replies (9) (5) (2) (*0 VAB.0001035217 * * Question No. 9: VCM Storage Tanks (b) How often are these tanks opened for internal inspection: 1. Once per year 2. 2-5 years 3. 6-10 years 4. Over 10 years 5. No regular basis (many use ultrasonic inspection) 6. No answer Virgin monomer tanks inspected infrequently. Day tanks inspected more frequently. (c) Have you had any corrosion problems in VCM storage tanks? Yes 4 No 16 Those indicating they have corrosion problems are in recovered VCM tanks or day tanks, not virgin VCM. Number of Replies (3) (8) (3) (2) (3) Question No. 10: Recovered VCM Handling (a) Do you distill your recovered VCM? Yes 3 No 17 N/A 1 (b) How do you control polyperoxide formation in your recovered VCM system? 1. Short retention time 2. Add an inhibitor 3. pH control - keep basic 4. Keep C>2 levels low 5. No precautions taken 6. No answer (7) (6) (4) (3) (3) (^\ A 1 ............................... -Mi- . 1 1 VAB.0001035218 1 ' < 1 I f- r- fll H|1 I I* |I." ii J. **11 * H Question No. 11: Reactor Entr; Do you require: 1. All flanges blinded 2. VCM flanges blinded only 3. Manway watch 4. Mechanical manway watch 5. Safety belt only 6. Safety belt and wristlets only (3 answered - wristlets only) 7. Safety belt and wristlets with line attached (2 answered - safety belt with line attached) 8. Lab entry analysis VCM/O2 9. Portable analyzer entry analysis VCM/O2 10. Respirator worn at all times li. Respirator worn at certain jobs 12. Gloves to be worn A No Yes No n/a Answer 13 6 1 3 12 1 5 16 4 1 4 11 1 4 6 11 2 11 1 1 3 3 2 12 1 3 2 l4 17 2 15 3 66 13 4 1 1 1 2 1 3 1 6 2 * VAB.0001035219