Page 6 - Temporary Instrumentation and Controls Bypass - CCPS Safe Work Practice

Potential Hazardous Consequences

Each instrumented safeguard exists for a reason - protecting against some hazard to personnel, the environment,
or assets. The potential consequence of improper bypassing, impairing, or jumpering of safeguards is the
occurrence of the very hazard the safeguard is designed to prevent or mitigate. These hazards typically include
fires, explosions, catastrophic overpressure events, toxic releases, or exposure of personnel to hazards inherent
to the process equipment.
Some things to consider before bypassing, impairing, or jumpering an instrument or control device:
g Most instruments and controls have been installed for a specific purpose. Are you able to confirm the purpose for
the device that you are considering to bypass?
g What does your process safety information (PSI) say? Have you referred to the interlock specification sheet,
Process Hazard Assessment (PHA), and other PSI to verify the purpose for the device that you are considering
to bypass?
g Bypassing a device is a change to your process safety information. Therefore, have you captured the bypass
in your MOC program like you would any other process change or followed a written procedure to manage
the change?

g Recognize that many devices may be identified in your PHA as a safeguard to manage/mitigate risk. Therefore,
bypassing such a device is essentially elevating risk. Are you authorized to bypass the device and increase risk?

g Does your authorization process define a specific communication/approval protocol to ensure safe design,
implementation, and review of the bypass?
g There may not be a direct pathway from the bypassing of a device to an incident. In some instances, even if it
is bypassed, an event may not occur. How are you preventing normalization of deviation associated with this
phenomenon (i.e., it has not happened before so it will not happen now)?
g Be aware that bypassing without consequences could lead to a false sense of security with operating and
maintenance personnel.
An important initial step before bypassing instrumentation or controls is to determine whether the governing process
safety codes permit the bypass of instrumentation or controls on operating processes and, if so, what the code
requirements are for executing a bypass.

3 SAFE WORK PRACTICE, TEMPORARY INSTRUMENTATION AND CONTROLS BYPASS