Procedure No. MAINT 018 Rev. No. 2

Certified

/ Area:
Refinery Wide / Procedure No.
MAINT 018
Effective Date:
August 19, 2004 / Mechanical Work In or On Cooling Towers / Rev. No.: 2
Written By:
C.J. Herman /
Auth. By: J.C. Reany
(Signature on file) / Page 1 of 3
SCOPE / This procedure provides guidelines for preparation of cooling towers and protecting workers while performing mechanical work on cooling towers.
HEALTH
Special PPE & Special Hazards / Legionella bacteria are common and grow in water, such as cooling towers. Legionella can enter the body through the lungs by inhaling very tiny, water mists that contain the bacteria. Under some conditions, the bacteria can cause a type of pneumonia (Legionnaires' Disease), or flu-like Pontiac Fever. To prevent exposure respirators (Half-mask with HEPA P-100 cartridges) will be worn when entering cooling towers or accessing the top of the cooling tower. Hydrocarbon exposure.
SAFETY / Fall hazards exist when entering a cooling tower. A safety harness with lanyard is required when entering a cooling tower.
Wet boards create a slipping hazard. Care must be taken when moving about on a cooling tower.
If misting remains after shutdown of the cell, poor visibility conditions may exist. Non-fogging safety glasses must be worn and, if necessary safety glasses removed if they create a visibility hazard. If safety glasses must be removed they should be off only for the time necessary to complete the task and safety exit the cell. Additional considerations may be necessary if using a full-face respirator.
REFERENCE
DOCUMENTS / OSHA Technical Manual SAF 032 Confined Space Permits, LOTO SAF 037, Hotwork SAF 033 & SAF 044.
SPECIAL MATERIALS & EQUIPMENT / Half-face respirator with HEPA P-100 cartridge or Powered Air Purifying Respirator with appropriate cartridge. Fall arrest harness and lanyard.

QUALITY

/

N/A

ENVIRONMENTAL / N/A

OVERVIEW

The purpose of this procedure is to provide guidance for the preparation of the cooling tower for entry into all parts of the cooling tower including the upper deck, the fan cowling, the basin and main structure to perform work. Work in cooling towers can create health and safety hazards. For this reason special precautions outlined in this procedure must be followed.

WARNING

Untreated cooling towers may create the formation of bacteria (legionella). This hazard can be transported through the rising mist associated with CoolingTowers creating an inhalation hazard. In addition, rising mist may create visibility and slippinghazards. It’s important to minimize exposure to rising mist through appropriate controls and PPE. To reduce mist, planned maintenance work should avoid cold weather.

WARNING

There is a potential for hydrocarbons in cooling towers. Test for hydrocarbons before issuing a hotwork or confined space permit.

1.0Procedure / 1.1Prior to entry all electrical switches will be locked out in accordance with the Lock-out Tag Out Procedure. Check with operators to insure shutdown of cooling tower,water shutoff to theriser ofthe cell to be worked in, and lock out of all equipment, including chemical injection to the tower.
NOTE: Biocide injection such as bleach (NaOCl) and sodium bromide (Nalco Acti-Brom 7342) should be left on to keep free chlorine levels sufficient to kill microbes.
__1.2Each person accessing the cooling tower shall wear, as a minimum, a half face respirator with HEPA cartridges. Due to the potential for cartridge plugging, a powered air-purifying respirator (PAPR) is recommended for extended time periods inside the confined space.
__1.3Each person entering the cell shall be wearing a safety harness and a lanyard secured to an appropriate support. Use of safety harness may be eliminated if handrails are installed on the work platform.
__1.4 Access to a cell will be completed through removal of shroud or main tower access door. Prior to entry, the operator will issue the Confined Space Entry Permit. Prior to issuing a permit testing will be completed for hydrocarbons or other likely substances that could leak into cooling water. Combination organic vapor/HEPA cartridges may be required per test results. Continuous hydrocarbon monitoring may be necessary, as conditions warrant.
__1.5After permission for entry has been given and immediately upon entering the cell, the fan blades must be secured to prevent rotation from the air draft.
__1.6 Once the fan blades have been secured, a work platformwill be laid out to the work area. The work platform should be of sufficient size (minimum width 36”) to cover the immediate work area and allow safe access to work area. Determination of the final size of covering will be made based on the type of work to be completed and the hazards identified during the prejob safety assessment.
__ 1.7 A pre-job assessment will be held to review the conditions of the cooling tower and scope of the work. The operator, scaffold foreman and lead mechanic will participate in the assessment.
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