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Method Statement 3.11.2 (A) - Repairing Ferrule Assembly on Live Mains

Document Information

Field Value
Document Reference MS 3.11.2 (A)
Issue Number 2
Issue Date 1 June 2026
Next Review 1 June 2027
Prepared By Sean Ashton
Approved By Aaron Mason, Director
Task No Task PPE to be worn Plant required Reference is made to the Team Pack risk assessment
3.11.2 (A) Repairing Ferrule Assembly on live mains As defined by on-site risk assessment. (To include Goggles) Works vehicle and hand tools. N/A

Hazards

  • Stored Energy in the Pipe
  • Ejection of damaged ferrule
  • Defective Plant and Equipment
  • Towing Techniques
  • Incorrect Loading
  • Insufficient Space
  • Manual Handling

Environmental Impacts

  • Noise
  • Dust
  • Light From Night working

Customer Impacts

  • Noise
  • Dust
  • Access

Training Required

As Per IMR specific contract training matrix

Additional Plant and Equipment

  • AVK Supacollar with greater diameter range is available (111.8 to 139mm) as required.
  • Mechanical Excavator

Permits Required

As Per IMR specific contract specifications and Client requirements.

COSHH Assessment Required

  • 2 Stroke Oil
  • Diesel/Petrol
  • Line Marker Spray
  • Lubricating Spray

Sequence of Operations and Control Methods

Mains Reduction/Isolation

  • Mains over 3Bar pressure are to be either reduced below 3 Bar or fully isolated.
  • The Supervisor shall ensure that Procedures for reduction of pressure in the main below 3Bar shutting down the parent main have been followed in line with the Water Network owner.
  • Caliper the parent main to determine the correct size and ensure all fittings are on site.
  • Where the main has been fully isolated the team can evaluate whether a new ferrule screw can be fitted within the original ferrule assembly opening.
  • Spray all the fittings with Chlorus as well as any cut surfaces connection.
  • Re-commission the parent main and check all new work for soundness.

Installation of Encapsulation Clamp

  • Expose by hand excavation the damaged ferrule assembly being aware of potential injury from tapping screw being ejected under high pressure water. Care to be taken during final exposure of ferrule assembly.
  • Iron, ductile, steel or PE main can have the Viking Johnson Easy-Clamp fitted while the main is live.
  • Assemble the clamp adjacent to the failed ferrule and slid over the hole encapsulating the leak prior to the clamp being tightened. Once the clamp is in place a new ferrule strap can be installed.
  • AC mains due to their oval shape require the clamp to be assembled directly over the main, therefore it is recommended that AC mains be isolated prior to the clamp being assembled.
  • The exception to this is where an AVK Supacollar with greater diameter range is available (111.8 to 139mm) which can be assembled adjacent to the failure and moved over the leak.

Under Pressure ferrule connection - Strap Ferrule

  • The team leader shall ensure that the excavation is sufficiently deeper than the main to allow the cleaning procedure to be followed
  • Once the main has been cleaned the strap ferrule will be attached ensuring that it is evenly tightened. The ferrule stopper will then be withdrawn and then installed within the drill stopper mounting
  • The team leader will ensure that the minimum distance between ferrules is observed at all times (up to 150mm - 3xdiameter, over 200mm - 2xdiameter)
  • On selecting the correct cutting tool the drill will be assembled on the ferrule ensuring that the valve is in the open position. The operator will then drill through the ferrule to the full depth of the cut
  • The cutter will then be withdrawn and the drill valve will be closed prior to installing the stopper-mounting tool.
  • The valve will then be opened and the ferrule stopper will be installed
  • The team leader shall remove the drill from the excavations and make the connection to the new service pipe ensuring that all fittings, tools etc have been sprayed/dropped ion chloros solution prior to use
  • The stopper will be lifted in order to commission and flush the service. At which time the fittings/service will be checked for leaks. If no leaks are visually apparent the excavation(s) will then be backfilled and reinstated

Under Pressure ferrule connection

  • In order to execute this activity, the following equipment will be required: Appropriate drilling machine(0.5"-1" Talbot 1 or similar) 110 volt generator
  • Appropriate ferrule (1" - 1.25" Talbot 2, 1.5" - 2" Talbot 3 or similar
  • The Supervisor shall ensure that the respective items of equipment are within calibration prior to use
  • The team leader will ensure that the excavation is sufficiently deeper than the main to allow the cleaning procedure to be followed and attachment of the chain
  • Once the main has been cleaned the correct mounting saddle will be selected and the drill and ferrule will be loaded into the machine. A check will be made to ensure that the ferrule is in the closed position
  • The drilling machine will then be set up on the main ensuring that the securing chains are evenly tightened the main will then be drilled and tapped with the swivel-locking pin in position. Once completed the drill will be withdrawn and the main tapped.
  • The swivel-locking pin will then be removed and rotated through 180 degrees at which time the ferrule will be installed. Venting the drill set will then complete the installation
  • Once the drilling machine is removed from the excavation the required fittings etc that are to be connected to the service will be sprayed/dipped in chloros solution prior to installation.
  • The stopper will be lifted in order to commission and flush the service. At which time the fittings/service will be checked for leaks. If no leaks are visually apparent the excavation(s) will then be backfilled and reinstated

Mains commissioning

  • Locate the sampling points, the preferred points are a ferrule plus pipe work and valve
  • Hydrants
  • Samples shall be taken by personnel who have been trained in sampling techniques
  • Samples shall be taken at terminal points, branches and selected points along the route as deemed necessary
Length of main Sampling required
Less than 100m 1
100m-300m 3
over 1000m 5
  • Samples shall be refrigerated and submitted to the Laboratory within 24hrs of sampling

Mains shall only be commissioned once all the samples have been passed, flushing water shall be appropriately discharged.

  • Open the vent(s) on the test piece(s) of the new main
  • Slowly open the valve on the parent main, flush the new main for 5 minutes
  • Slowly close the vent(s) at the flushing point(s) and allow the pressure in the new main to equalise to that in the parent main
  • Fully open valve on parent main
  • Remove all temporary fittings and gauges
  • Check all new work for soundness