WI’s STANDARD PROCEDURE – ENGINE UNITS

1. Take the Degassing unit to the job-site with two operators, one for operation and the other for monitoring and safety watch.
2. Review the following with the Client (or General Contractor) project coordinator(s) and with all WI and non-WI operators present at the job-site:
   1. Work permit requirements,
   2. WI’s degassing procedures,
   3. Safety and Health Precaution,
   4. Installation of an air-horn or coppus blower immediately after degassing.
3. Sample the tank vapor space with Bacharach TLV for hydrocarbon content. Make an estimate for the degassing time and report the time estimate to the project coordinator.
4. If there exists no access to the tank vapor space, make a request to the project coordinator that WI’s manway be installed on the tank by Client’s personnel or by the contractor.
5. Bond the Degassing unit. Connect the 3” hose to the tank via the existing access or via WI’s manway.
6. Start the degassing engines on propane from the unit’s propane tank, after making sure that the path to the storage tank is still closed.
7. After the engines have warmed up for 10 minutes, start extracting tank vapor into the engines.
8. Monitor the tank vapor space, extracted vapor at inlet to the Degassing unit, and engine exhaust for hydrocarbon concentrations with the TLV unit. Record these values and the vapor extraction rates (as measured by the Dwyer anemometer) on the log sheet every 15 to 30 minutes.
9. Leave the TLV unit running immediately upwind of the Degassing unit with the alarm set at 5% of LEL. Should the audible alarm ring at any time during the degassing operation, shut the degassing unit immediately.
10. After a few hours of degassing, revise the time estimate and report to the project coordinator. If the project is likely to take more than 8 hours, discuss the needs for lighting, manpower assignment during the evening hours, etc. with the project coordinator.
11. Continue degassing until one of the following conditions have been met:
    1. Tank vapor hydrocarbon contents have been reduced to 19,000 ppmw or lower, or
    2. Four volumes of tank vapor space have been extracted.
12. If the client requires further degassing (e.g., 10% LEL), continue degassing until the client’s requirement is satisfied.
13. Report to the project coordinator that the TNRCC requirement has been satisfied. If approved for termination, switch engines back to propane and close the extraction valve. Disconnect the extraction hose from the storage tank manway.
14. Flush the extraction hose with air for a minimum of 5 minutes before engine shut down.
15. Check the following before leaving the job-site:
    1. An air horn or a coppus blower is operating,
    2. The project coordinator has authorized WI’s departure from the job-site, and
    3. The project coordinator has signed the Log sheets.

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