Page 13 - Confined Space Training - Student Manual 2021

Confined space injuries and deaths can also occur if energy sources are not properly secured
and isolated from the space. Because of this potential, OSHA requires that:
A. All valves and electrical equipment must be properly locked out according to the
lockout/tagout standard.
B. Connecting pipes should be blanked off, separated, or sealed.
C. Pipelines must be flushed, drained and isolated to prevent unexpected exposure to
contaminants.

First Priority: Isolate the Confined Space

Storyline: This story demonstrates why it is necessary to isolate confined spaces.

Three workers were in a six-foot square storm drainage junction box, which was ten feet deep.
They were performing maintenance work while water from the nearby retention basin was being
held back by an inflated rubber bladder in a 60-inch feed main. The bladder ruptured, releasing
thousands of gallons of water that raced through the pipe drowning one of the workers. Two other
workers escaped with minor injuries.

Step-by-Step Isolation
Ensure the area around the confined space is clear of debris and other material that could cause
injury or disruption of activities. Isolate all lines/pipes/ducts/tubing that serve the confined space.
Isolation could involve one or more of the following techniques.

Blanking/Blinding. Insert a blank in the flange closest to the confined space. By unbolting
the flange and inserting a blank, then re-bolting the flange, you prevent fluids, gases, or
pressures from being transmitted to the space without warning. This solution positively
prevents unwanted materials from reaching the space.

Any blanks already must be pulled and inspected before being used as an isolation device.

Ensure the blanks remain in place for the duration of the confined space entry process. Utilize
lockout/tagout to ensure the safety of the process.

Isolated Configuration

Confined Space Training for Entrants, Attendants & Supervisors 13