Confined Space Entry Procedure PDF

?£- Chapter 14 • Safety Management Systems OBJECTIVE 6 ^Defirie^:ideniify^^ |g'ancf<hfrypiocedu?^|i^ CONFINED SPACE ENTRY Note: The following (up to and including the section titled "Standby Person") is taken from the B.C. OH&S Regulations. Confined Space means an area, other than an underground...

?£- Chapter 14 • Safety Management Systems OBJECTIVE 6 ^Defirie^:ideniify^^ |g'ancf<hfrypiocedu?^|i^ CONFINED SPACE ENTRY Note: The following (up to and including the section titled "Standby Person") is taken from the B.C. OH&S Regulations. Confined Space means an area, other than an underground working, that: • Is enclosed or partially enclosed • Is not designed or intended for continuous human occupancy • Has limited or restricted means for entry or exit that may complicate the provision of first aid, evacuation, rescue or other emergency response service • Is large enough and so configured that a worker could enter to perform assigned work Workers must be protected from dangerous substances, which can be discharged from pipes or conduits leading to the confined space. In these situations the closing and securing of valves is not adequate to isolate workers from the danger. Piping must be disconnected, blanked or blinded. A blank is a solid plate installed to block the end of a pipe. Where pipes have threaded joints, threaded plugs or caps must be used to blind (shut off) the Une. A spectacle blank has a visual indication that a blank has been installed. Blanks are also referred to as blinds. General Precautions • Before opening any line (pipe), close and lock out appropriate upstream valves, depressurize the line, and then drain the system • Make disconnections as close as possible to the confined space to minimize the chance of residues in the line from entering the confined space • Where toxic or flammable air contaminants could be discharged at a disconnect point, provide necessary atmospheric testing, warning devices and protective equipment Blanks and Blinds Blanking or blinding means the absolute closure of adjacent piping, by fastening across its bore a solid plate or cap that completely covers the bore and that is capable of withstanding the maximum pressure of the adjacent piping. Adjacent piping means a device such as a pipe, line, duct or conduit which is connected to a confined space or is so located as to allow a substance from within the device to enter the confined space. Blank means a solid plate installed through the cross-sectional area of a pipe, usuaUy at a flanged connection. Blind means a solid plate installed at the end of a pipe, which has at that point been physically disconnected from a piping system. • Blanks and blinds must be capable of withstanding anticipated line pressure and temperature and be non-reactive with the line and its contents • Where necessary, install gaskets on the pressure side of a blank or blind to prevent leakage • Provide a means of visual indication of blanks and blinds at the installation point BliS%— IU^%;^-JriSlB"X 3rd Class Edition 2.5 • Part A2 6'arery M'duciytnncm <Jjrotonr fS i'l' • Two systems available for making blanks visible are tabbed blanks and open/solid plate (spectacle) combmations • A flanged bolt to which a lock can be applied is recommended to prevent unauthorized removal of the blank • Keep records that identify the blanked lines and the locations of blanks and bUnds a!i .'! llfli Welded and Continuous Systems In some situations, blanks or blinds may not be practical. Examples include continuous systems such as sewers and aU-welded piping systems that may be required by specific engineering or design codes because of extremely high pressures or temperatures. In these cases written procedures must be developed which provide equivalent protection. Procedures should cover: • Locking out appropriate line valves • Emptying and cleaning lines • Use of plug and vent systems such as the plumber's baU, mud plug or pipe pig, where appropriate • Monitormg for air contaminants at the point of line entry mto the confined space • Use air-suppUed respirators or make provision for additional ventilation to prevent contaminants from building up Lookout Program A lookout program must be established to ensure the proper use of lookout in conformity with the Industrial Health and Safety Regulations and measures. Measures m the lockout program wiU include, but are not limited to the following: • A written lockout procedure must be available for all work in confined spaces • Workers must be instructed in and follow those procedures • Each worker must work under the protection of his or her assigned locks • Each person must personally lockout the control devices before beginning work. If maintenance is not complete at the end of the work shift there must be a continuity of the lookout between shifts • Energy sources such as steam, compressed air and hydraulics must be de-energized • Radiation devices such as density and level indicators must be closed and locked prior to allowing work to be conducted nearby • If work procedures could produce movement of de-energized equipment (for example, if paddle-blades on a turbine are used to provide points of leverage), the equipment must be mechanically restrained or work procedures that assure equivalent protection must be established • A system of locking entryways in the open position must be provided in circumstances where unauthorized or inadvertent closure would endanger workers inside I 3rd Class Edition 2.5 • Part A2 '.I)' \; I:'1 ') ?& Chapter 14 • Safety Management Systems Entry and Exit Points A confined space enb-y program requires consideration of the following questions to control the hazards at entry^ and exit points. • Are warning signs or other means of communication provided to prevent unauthorized entry? • Are traffic control measures provided where necessary? • Do fbced ladders conform with standards acceptable to the WCB? • Are individual rung ladders for precast reinforced concrete manholes installed as required byASTM Specification C478? • For manhole or well entoy, is the maximum discharge from the top of the manhole cover to the first rung 50 cm? (where a handheld is provided above the first rung, the maximum distance is 66 cm) • Are temporary ladders (for example, aluminum) non-reactive with residues on the floor of the confined space? • Does the standby area have the necessary guardrails and toe board? • Are access openings large enough to permit rescue? • Are the design and size of the standby area adequate to permit effective rescue? • Will ventilation or other equipment obstruct the access or exit area? • Is the standby area provided with rescue equipment? • Is the entryway locked in the open position where necessary? • When the work is complete and, prior to dosing off the space, has a check been conducted to ensure all workers have vacated the space? Atmospheric Testing A confined space-testing program must consider: • Qualifications of testing personnel: only a qualified worker as identified in the written work procedures may test the ataiosphere in the confined space • Selection of test equipment which must be accurate and reliable • The person doing the test must know where to test, how to test, when to test, how often to test and must record and be able to interpret the results Cleaning, Purging and Ventilation Cleaning and purging are preparation procedures carried out prior to worker entry. Cleanmg procedures include steam or water cleaning, neutralization, descalmg and special solvent application. Whenever possible, clean the space and remove wastes without entry. Continuous mechanical ventilation (the use of air movers, such as fans, combined with ductwork or other means of directing the air) is a basic requirement for the control of hazardous atmospheres. Every confined space should be ventilated continuously while a worker is inside the space. Check OH&S for exemptions. Effective general ventilation systems provide good airflow. They also scour the entire airspace, while not introducmg a hazardous atmosphere into the space. Standby Persons • A standby person must be present while a worker is inside a confined space • The standby person must be in continuous communication with the worker • The standby person must have a means to immediately summon rescue personnel Depending on the hazard rating of the confined space, special provisions for standby person may be employed. 3rd Class Edition 2.5 • Part A2 Safety Management Systems • Chapter 14 •f® fill Sl EXAMPLE OF CONFINED SPACE ENTRY PROCEDURE Note: The remamder of Objective 6 is a specific confined space entry procedure used in one particular process facility. It should not be construed as legislated detail. Confined Space: An enclosed or partially enclosed space, which is or may become hazardous to a Permit Centre. 8 1. Confined Space Classifications and Required Controls liil ' worker entering it. Examples of confined spaces are: sewers, tanks, valve pits, furnaces, exchanger shells, pipes, and excavations deeper than 1.2 m. Issuing of Entry Permits for Confined Spaces: Permits will be issued by Operations from the •!]1 ; •\.',t.\ M Confined spaces have been divided into 3 distinct levels to properly define the required controls with the potential hazards. Each hazard level has its own conbrols for gas testing, trained standby and rescue people, and safe entry procedures. Level 1: Entry mto a level 1 confined space poses unmediate danger to the worker's life or health. These dangers include, but are not lunited to, oxygen deficiency, explosive or flammable ataaospheres and concentrations of toxic substances. Examples of Level 1 entry are oily water sewer -with an inert atmosphere. The entry requires a Safe Work Plan, approved by the Division Manager. The controls for this level include: Qualt&ed Standby Person, Qualified Rescue Person, Valid Work Permit, Safe Entry Tag, Safe Work Plan or Procedure, Gas Tests Level 2: Entry into a level 2 confined space does not present immediate danger to the worker's life or health but has the potential to if preventive measures are not used. The potential exists for conditions to change in the confmed space. Examples of a level 2 entry would be cleaning tower trays or replacing a scrubber grid. The work is carried out inside a pressure vessel. The conb-ols for this level include: Qualified Standby Person, Gas Tests, Safe Entry Tag, Valid Work Permit Level 3: Entry into a level 3 confined space where the only potential hazard is a restricted access and egress. An example of a level 3 is mspecting a clean exchanger shell. A valid entry permit or a log m book may be used. The logbook must contain time/date of entry, names, reason for entry expected and actual return times. The permit user must sign it. The controls for this level include: Gas Tests, Valid Work Permit or Sign-m, Safe Enby Tag. A standby person is optional. 2. Confined Space Entry Preparations/Isolations • AH confined spaces must be isolated prior to entry ' • AH electrical, radiation and mechanical equipment must be locked and tagged • Where it is not possible to positively isolate the confined space, a Safe Work Plan must be developed • • Safely remove the process materials from the confined space • The confined space must be thoroughly ventilated with air, using exhaust fans or blowers. The air must be; pulled through the total volume of the confined space. The exception would be where the confined space must be kept inert • The number locations and capacity of fans or blowers/aii movers must be determined to ensure adequate ventilation • A properly completed Safe Entry Tag must be in place before permits are issued 3rd Class Edition 2.5' Part A2 ill HE ?& Chapter 14 '• Safety Management Systems Inert Entries: Where entry into a confined space that contains an inert atmosphere is required, the requirements of Level 1 Entry must be met. Vessels with Nudeonic Instrumentation: Before entry is permitted, the source carriers must be withdrawn into the holders and tests must be completed to ensure the radiation levels are within accepted Umits. The Quality Assurance Department is responsible for determining the appropriate levels. 3. Entry Permit Gas Testing Requirements The vessel must be thoroughly gas tested for % LEL, 03 content, and if applicable, toxic gas, vapour, dust or fumes at representative points. A QUALIFIED person must do 'the tests. The results of each test must be recorded on the Safe Entry Tag. Maximum, duration between tests is 6 hours. The exact time of the gas test must be recorded on the Tag, not a blanket time frame, for example, all tests due at 0600 hrs. The following guidelmes and limitations shaU apply. • Explosive Gases (LEL) A confined space entry permit can be issued for entry -without breathing equipment if gas tests prove that the explosive vapour concentration is not above 0% of the LEL. • A confined space permit can be issued for cold work tf gas tests prove that the explosive vapour concentration is not above 20% of the LEL. Breathing equipment and a Safe Work Plan are required for this type ofentay Oxygen: content greater than 19.5% but less than 23% for entry without breathing equipment. Toxic Gas concentrations must be less than the Occupational Exposure Limit or Short Term Exposure Lunit of the toxic gas. 4. Occupational Exposure Limits (As per the Occupational Health and Safety Act, Chemical Hazards Regulation) Using the exposure limits below, a worker may work in an area containing ammonia for 8 hours if the concentration 25 ppm or lower. If the ammonia concentration mcreases to 35 ppm or above, the exposure time Umit is 15 minutes. Wliubiii%SBISIIi8Wil%l^iia^ 25ppm 35ppm N/A 5000 ppm 15000ppm N/A Carbon Monoxide 25 ppm 200 ppm N/A Hydrogen Sulphide 10 ppm 15ppm 20ppm Benzene 1 ppm 5ppm N/A Sulphur Dioxide 2 ppm 5ppm N/A Ammonia Carbon Dioxide 3rd Class Edition 2.5 • Part A2