Line Opening - Strategies & Effective Practices to Manage and Mitigate Hazards

Effective Practices to Manage and Mitigate Hazards

Reduce risk by minimizing work on lines connected to equipment still in operation

• Consider deferring line breaking to a future turnaround or outage when inventories of hazardous materials are at a minimum or eliminated.

Properly isolate line or equipment to be worked on

• Use of manual valves.

• Use of a double-block-and-bleed configuration to ensure manual valves are not leaking through.

• Do not use control valves as an isolation device.

• Do not work on line or equipment if there is an indication that isolation valve may be leaking through.

• Lock-out/tag-out (LOTO) should be complete before line opening permit is issued.

Clean the line or equipment before opening

• Develop procedures to clean or flush the line to minimize the amount of hazardous materials present.

Verify that the lines or equipment are drained and clean before proceeding with line opening task

• Develop procedures to ensure that the lines or equipment are emptied, purged, flushed, drained, vented, isolated and locked/tagged as applicable to confirm the system is free from recognized hazards.

• Verify that drains are not plugged giving a false indication that the line is empty.

Assure that personnel are not exposed to hazardous materials while draining the lines or equipment

• Develop procedures to empty, purge, flush, drain, vent and properly isolate lines and equipment.

• Verify that de-pressurization of lines or equipment and absence of material has been accomplished by opening vents and drains or by other means deemed appropriate.

• Include proper disposal of hazardous materials in draining procedures.

• For Line/Equipment Opening inside an operating building, extra caution may be needed to address potential asphyxiation hazards.

Treat initial line/equipment opening as if hazardous material is present

• Require personnel performing line breaking to wear proper PPE for the hazardous material that is normally in the line.

• PPE should remain in place until personnel verifies that the line is empty and clean.

• Loosen the flange bolts away from you first to minimize exposure in case of a release.

Identify location of each line or equipment opening

• Identify the location of line opening by marking on the pipe.

• Positively identify location of each line opening at the time of on-site inspection.

• During on-site inspection verify that person performing the work or accepting the permit knows the location of the line opening.

• Use the P&ID to determine all isolation/blinding or block/bleed valve locations.  Develop an Isolation/blinding/block/bleed list for the job. 

Identify access issue or congestion in the area

• Assure adequate access to the location of the line opening is available.

• Identify any congestion issues and possible additional hazard (i.e. ¼” valves that could be bumped open on another line).

Use special precautions for opening a vent line or flare header

• If possible, make certain that any equipment connected to the vent header is down and isolated.

• If a vent header is used as a relief device vent develop procedures to make sure that pressure in upstream equipment is monitored and equipment is shutdown before pressure reaches the relief device setting.

Avoid sparks if the line must be cut

• Obtain Hot Work permit.

• On lines or equipment which may have contained flammable and/or toxic liquids or gases, test with a properly calibrated combustible gas indicator initially and intermittently during work.

• Use cold cutting methods to cut a line that contained flammables.

• Consider purging the line with nitrogen to minimize possibility of fire.

• Connect both side of the area to be cut with ground straps before cutting to minimize ignition potential.

Analyze hazards and identify means of control

• Survey the worksite and look for potential sources of ignition if the line opening involves flammable materials.

• Ignition sources could include hot equipment surfaces, vehicles or hot work being performed in the area, including above and below.

• Ensure that where work is performed on elevated piping or equipment, the area below the work will be barricaded and splash pans/spark containment provided as needed.

Understand operational status

• If line or equipment is isolated with a single valve, consider the possibility of leakage.

Recognize changes in process conditions

• Line or equipment openings that last over several hours or days need to be secured by installing blind flanges or in-line blinds to prevent unexpected releases.

• Treat disconnecting a blind flange as a line opening.

Ensure resources to adequately assess safe work activities

• Time pressure and/or task complexity on authorizing personnel to get permits issued can compromise the safety process through the adoption of a “seems OK to be” process.

• Assure that there are enough resources to properly inspect the line opening site and positively identify the location of the line opening before permit is issued.

Create safe environment

• Require proper PPE to protect personnel during initial line breaking.

• Personnel breaking lines must place themselves in a defensive position to avoid a spray of liquid or release when attempting the initial opening.

• Identify location of the nearest safety shower and eye wash to be used in case of an emergency.

• Install blind flanges on lines in hazardous service when equipment is removed for maintenance.

Ensure that all workers are competent to execute their responsibilities

• Provide training to all personnel in Line/Equipment breaking policies and procedures.

• Ensuring contractors have required craft qualifications.

• Closely supervise all contractors to ensure they are aware of all hazards and how to respond to emergencies.

Continuous monitoring of the envi-ronment; stopping work if hazardous material is detected in the line

• Line or equipment opening work should be stopped if presence of hazardous material is detected.

• Hazard evaluation should be completed to determine how the work should proceed or if it should be postponed.

Communication is essential between the control room, the Operating personnel and the people conducting the work

• Communication with the control room at all times is essential.

• If an emergency alarm is sounded, all line opening work must cease immediately.

• Area should be re-inspected and line opening permit re-issued after emergency is resolved.