DN-08e Live service isolation

• Site conducted

• Conducted on

  Date

• Prepared by

• Location
  Address

• Operative being assessed

  Yes

  No

  N/A

• O = Observed K = Knowledge S = Simulated

Actions on site

• Carries out visual inspection of the air hose and couplings, and performs a ‘pull test’ to ensure the hose <br>is correctly attached

  Yes

  No

  N/A

• Uses the Voltstick prior to undertaking any work on any exposed metalwork to ensure it is safe to <br>continue and repeats when necessary

  Yes

  No

  N/A

• Carries out checks to establish the number of customers being supplied and isolates ECV prior to <br>disconnection

  Yes

  No

  N/A

• Ensures the gas service is adequately exposed

  Yes

  No

  N/A

• Cleans the service pipe and selects the correct size of clamp for the pipe to be isolated

  Yes

  No

  N/A

• Checks condition of the clamp rubber seal, operation of the valves, the condition of the pipe and <br>confirms the actions to be taken in the event of pipe corrosion

  Yes

  No

  N/A

• Fits the clamp with the 45° angle facing the flow of gas ensuring there is enough clear pipe for the <br>stopper to be fully fitted and a suitable length removed

  Yes

  No

  N/A

• Carries out checks on the drill threads, main drive shaft and quick release couplings

  Yes

  No

  N/A

• Select the correct sized cup drill and installs onto the drill shaft. Withdraws the cup drill into the drill <br>body and attaches the drill assembly onto the right angled valve of the clamp

  Yes

  No

  N/A

• Selects the stopper chamber and charges the star gland seal with approved grease

  Yes

  No

  N/A

• Inserts the stopper carry spring-rod through the gland, fits the correct sized stopper and applies<br>approved lubricating spray. Withdraws the stopper into the chamber and attach to the 45° angled valve <br>on the clamp

  Yes

  No

  N/A

• Ensures both valves are open, attaches pressure gauge to stopper chamber and applies test pressure of <br>30mbar using hand pump through drill shaft hose connection. Tests for 5 minutes ensuring there is no <br>pressure drop

  Yes

  No

  N/A

• Carries out further checks to establish the reason for the leakage and rectifies, if necessary

  Yes

  No

  N/A

• Releases test pressure and removes pump but leaves the gauge in position to monitor for gas pressure <br>during drilling operation

  Yes

  No

  N/A

• Wears electrical insulated gloves throughout the drilling operation when the equipment is being used <br>remotely from the service connection to the main in case the pipe contains a live cable that was not <br>previously detected

  Yes

  No

  N/A

• Turns the feed screw clockwise until the drill bit touches the service pipe. Calculates the drill travel <br>distance and marks the position on the drill spindle with adhesive tape

  Yes

  No

  N/A

• Drills the hole using a ratchet or pneumatic drive, turning the feed screw clockwise slowly to maintain <br>controlled travel

  Yes

  No

  N/A

• Confirms hole is drilled by turning feed screw clockwise for 2 full rotations and checks against spindle <br>tape mark

  Yes

  No

  N/A

• Fully retracts the drill by turning the feed screw anti-clockwise and closes the right angled valve. <br>Removes the drill and removes the coupon or retrieves it by using a magnet once the service pipe is cut

  Yes

  No

  N/A

• Inserts the stopper into the service using minimal force and carries out a let-by test to ensure the <br>stopper has created a seal

  Yes

  No

  N/A

• Question - What action would you take if the stopper fails to create a seal?

• Answer - The stopper can be removed, re-inserted or swapped if necessary to create a seal but if a seal cannot
  be obtained, then the technique should be abandoned and conventional techniques in accordance with
  the Servicelaying procedure

• Unscrews and retracts the spring-rod by turning it anticlockwise and closes the 45° angled valve on <br>successful completion of a let-by test proving that the stopper is in the desired position

  Yes

  No

  N/A

• Removes the entire clamp assembly by either dismantling the individual parts or by removing it as one

  Yes

  No

  N/A

• Fits a temporary continuity bond (TCB) across section to be removed ensuring that the pipe where the <br>TCB is to be clamped is clean and wired brushed to a bright finish to ensure a good electrical contact

  Yes

  No

  N/A

• Question - What action needs to take place if the Voltstick glowed or sparking occurred when fitting or removing the TCB?

• Answer - Cease work and inform team manager

• Cuts the service pipe through the previously drilled hole using a hacksaw or wheel cutters

  Yes

  No

  N/A

• Question - What action should be taken if a leak occurs whilst cutting off the service?

  Yes

  No

  N/A

• Answer - Wear breathing apparatus until the cut is complete and a cap fitted
  

• Makes a second cut at a suitable position exposing the rear of the stopper to allow either, the use of <br>Live Service Insertion (LSI) equipment to relay the service or a cap end if it is being abandoned

  Yes

  No

  N/A

Sign off

• Name of assessor

  Yes

  No

  N/A

• Pass or refer for additional training

  Yes

  No

  N/A

• Carries out visual inspection of the air hose and couplings, and performs a pull test to ensure the hose is correctly attached

• Uses the Voltstick prior to undertaking any work on any exposed metalwork to ensure it is safe to continue and repeats when necessary

• Carries out checks to establish the number of customers being supplied and isolates ECV prior to disconnection

• Ensures the gas service is adequately exposed

• Cleans the service pipe and selects the correct size of clamp for the pipe to be isolated

• Checks condition of the clamp rubber seal, operation of the valves, the condition of the pipe and confirms the actions to be taken in the event of pipe corrosion

• Fits the clamp with the 45* angle facing the flow of gas ensuring there is enough clear pipe for the stopper to be fully fitted and a suitable length removed

• Carries out checks on the drill threads, main drive shaft and quick release couplings

• Select the correct sized cup drill and installs onto the drill shaft. Withdraws the cup drill into the drill body and attaches the drill assembly onto the right angled valve of the clamp

• Selects the stopper chamber and charges the star gland seal with approved grease

• Inserts the stopper carry spring-rod through the gland, fits the correct sized stopper and applies approved lubricating spray. Withdraws the stopper into the chamber and attach to the 45" angled valve on the clamp

• Ensures both valves are open, attaches pressure gauge to stopper chamber and applies test pressure of 30mbar using hand pump through drill shaft hose connection Tests for 5 minutes ensuring there is no pressure drop

• Carries out further checks to establish the reason for the leakage and rectifies, if necessary

• Releases test pressure and removes pump but leaves the gauge in position to monitor for gas pressure during drilling operation

• Wears electrical insulated gloves throughout the drilling operation when the equipment is being used remotely from the service connection to the main in case the pipe contains a live cable that was not previously detected

• Oct 2017

  Date