procedure no. maint 018 rev. no. 2 certified ========= area: refinery wide procedure no. maint 018 effective date:
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 Cooling Towers creating an inhalation hazard. In
addition, rising mist may create visibility and slipping hazards. 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.
Procedure
1.1 Prior 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 the riser of the
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.
__1.2 Each 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.
__1.3 Each 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.
__1.5 After 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 platform will 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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