1.7 Energy Isolation

type of energy source

electrical

transmissions lines, transformer circuit breakers, motors, lighting, impressed current for cathodic protection

hydraulic

pneumatic

air/gas sys under pressure plant air, hydrocarbon gas, gas cylinder

chemical

kinetic

stored or potential

radiation

thermal

liq under pressure e.g. pumps hydro testing hydraulic sys

flammable, toxic, corrosive, reactive e.g. acid & caustic hydrocarbons flammable, h2s toxic, hydrogen peroxide, pyrophoric material

springs counter weights raised loads

moving objects e.g. fan blades, fan belts, agitators, flywheel

ionizing source e.g. radiography activities

extreme temp e.g. hot surface, cryogenic material, steam

energy release & consequences

  • electrical electrocution, burn
  • chemical burn cold burn
  • pneumatic high impact injury cut
  • mechanical cut flying object
  • radiation burn cell mutation
  • hydraulic injury cut
  • thermal burn

all energy sources shall be isolated n brought down to zero energy state before work begins

EI = isolation + LOTO
isolation = the act of separating smthg

LOTOTO

physical

electrical

positive isolation most secure
spool /valve removal
blind /spade isolation...blind type rated, correct material n correct size


double block and bleed (DBB)


single valve isolation

situation require positive iso

  • confined space entry
  • hot /cold work on a unit which is part of a sys containing 🖊 combustible /explosive material 🖊 energy source ❗ high temp (touch 60deg heat stress 38deg) ❗ high press (pneu /hydrau) ❗ asphyxiant ❗ toxic ❗ corrosive ❗ radioactive

local push button isolation
MCC isolation ✅ switch off ✅ rack out

Lock Out
The placement of a locking device on an energy isolating device. Eg. Lock & chain on an isolation valve, electrical breaker locked & open position, etc.


Tag Out
The placement of a tag on an energy isolating or lock out device, e.g. on the lock, at the blind or valve, lock at the lockout box,etc


Try Out
After all switches, valves and devices are locked out and tagged, and the equipment is cleared of personnel, attempts are then made to try starting the equipment (push button, actuators, etc.)

a series of locks w/ a single common master key

color coded tag
blue = operation
red = electrical
yellow = ionizing radiation
brown = common disposable tag used at lockout box
green = spade /blind

Roles & Responsibilities

Approving Authority(AA)
responsible for ensuring that any equipment being worked on is isolated and made safe of any energy hazard before approving the PTW. He also performs the energy isolation and lock-out tag-out (LOTO) activities if required.

Approving Authority Representative(AAR)
In addition to other responsibilities related to the PTW system, the AAR is responsible to perform energy isolation and LOTO, as instructed by the AA, and ensure that the site and equipment are safe for the PTW to be approved and issued

Receiving Authority(RA)
is responsible to perform energy isolation and LOTO, as instructed by the AA, and ensure that the site and equipment are safe for the PTW to be approved and issued

Radiation Protection Officer / Supervisor (RPO/RPS)
The RPO/RPS is responsible to ensure that devices containing radioactive sources are isolated
/ shuttered, locked and tagged or removed, as part of preparation for confined space work or work that may expose people to the radioactive source. He issues the Radiation Certificate when he is satisfied that it is safe to do so

When planning for energy isolation, the following should be considered:

  • Plan and organize the work properly taking account of different types of energy sources
    and their potential hazards
  • Establish a procedure or JMS and communicate to the workers

management of keys

Field/Substation
Operations key (Group lock with master key)
Electrical key (department lock with individual key)
RPO key (department lock with individual key)


Lockout Box Station
AA key (department lock with individual key)
RA key (department lock with individual key)

  • Handover between shifts or change of AA /RA
    🖊 keys shall be handed over personally and recorded in the key handover log book by each department
    🖊 handover of PTW, PIC, EIC and other certificates
  • Unused lock, key & tag stored at a safe place in each department
  • Spare common keys shall be kept by Shift Manager or equivalent for use during emergency