Document v1Bpkjr96kM6KQKpQEm9gq74R

1 April 25, 1984 G=n=RRL( CATMOOiC PROTECTION SERVICES, nc Tenneco Oil Company p. 0. Box 849 Pasadena, Texas 77501-0849 Attention: Mr. Paul R. Prokish Reference: Cathodic Protection Survey of Pasadena Plant and Off-Site Pipelines - Contract number 90-2945, P. 0. I138653-01A Dear Mr. Prokish: A cathodic protection survey of the above referenced facilities was completed on March 21, 1984. This survey was conducted to determine the effectiveness of the cathodic protection system for the plants underground metallic struc tures and off-site pipelines. Survey Procedures Plpe-to-soil potentials were measured at random test points throughout th plant. The test point locations can be seen on Tenneco drawings number C-TM1-200-F-112 and C-PC1-P-01-353. These potential measurements were taken using a high impedance voltmeter in conjuction with a standard coppercopper sulphate reference electrode. The rectifiers were inspected and the voltage and amperage output was measured. Anode current output for each anode in the deep well groundbeds was recorded. Plpe-to-soil potentials and magnesium anode current output were taken at test stations for the off-site pipelines. Data pertaining to this survey can be seen on the attached data sheets. Survey Results One criteria for effective cathodic protection is a minimum of -0.85 volts DC. -This measurement is taken between a standard copper-copper sulphate r ference electrode and the pipeline. Potential measurements in the P.A. unit area were below acceptable levels. The current output for rectifiers "A" and "B" were increased to there maximum output after low potentials w re discovered in this area. After the rectifiers' output was increased, potential measurements were repeated. Plpe-to-soil potentials did increase, but did not Increase above the required -0.85 volts. Rectifier "C" has an internal intermittent electrical short. During this survey the rectifier was operating satisfactorily. After the survey was 7077 PERIMETER RURK DRIVE TX 77041 4B6-&4QO iBooi eas-GCPs TELEX: 79-3349 "luvta Rubies o<*oo otwviR OFPOCB WWUCMERTIR. (NSlANO kM Luo l-OUETCPI LOSAPwGCtfS MCmA^iO.Tx MT LALKVL. TEN 2586 KCW 0*=Lt TlJLfcA Mr. Paul R. Proklsh April 25, 1984 Page two completed the rectifier was taken out of service, repaired and returned to service. Rectifier "An was found to have no current output at the beginning of the survey. The problem was investigated and found to be a loose connection for the positive cable in the anode junction box.' This connection was repaired and the rectifier is operating correctly. Rectifier "D" was found to have a damaged anode junction box. The rectifier and anodes are operating satisfactorily, but the box should be repaired or replaced. Over all the pipe-to-soil potential measurements were above the -0.85 volts required for cathodic protection except in the area of the P.A. unit. Plpe-to-soll potential measurements were taken at random test stations for the off-site acetylene, hydrogen, AOG and VCM pipelines. All potentials recorded were above the criteria for cathodic protection. . Recommenda tions It is recommended that a new groundbed and rectifier be installed in the area of the P.A. unit. The system recommended would be similar to the existing systems. The groundbed would be a 8" x 200* hole with 18 Durichlor 51 type "M" anodes. Metallurgical coke breeze would be pumped around the anodes. The anode lead wires would be terminated in a junction box with current measuring shunts. A Universal 45 volts, 60 amp air cooled rectifier would be installed on a pole near the groundbed location. The AC power required for the rectifier would be 480 volts, 3 phase. It is also recommended that the anode junction box for rectifier "D" be repaired or replaced. Some test points shown on drawing number C-PC1-P-01-353 are located a few feet from each other. It is recommended that if two test points are located in close proximity, that one be omitted. Test point number 12 is-on the dock above the water line and therefore, should be omitted. We recommend that you continue to check the rectifiers, on a monthly basis and have a complete plant survey yearly. General Cathodic Protection Services, Inc., would be pleased to install the recommended groundbed and rectifier for a turnkey price of $12,351.00. The AC power to the rectifier would be the responsibility of Tenneco. This price is valid for a period to 90 days. TEN 2587 Mr. Paul R. Prokish April 25, 1984 Page three Enclosed is our invoice number 01-TX-25037F in the amount of $1,492.00 to cover the cost of this survey and rectifier repairs. We appreciate this opportunity to have been of service to your company. Very truly yours. General Cathodic Protection Services, Inc. TAK/afm