Leak Identification and Assessment

Every successful clamp begins with a disciplined field investigation. The activities below are executed as laid out in “Beruseal Method Statement PROBS06ENG Rev02“, and are recorded on the “Temporary Leak Repair (TLR) report” that accompanies the device for the rest of its life cycle.

On-site scoping: Technicians confirm that the leak is suitable for an on-line leak sealing device, identify the leak mechanism and gather all process-safety information needed for a preliminary risk ranking. At least two certified technicians visit the line, complete the Temporary Leak Repair (TLR) report and daily risk assessment, and take photographs of the defect. Critical data captured include pipe outside diameter, wall thickness/Non-Destructive Testing (NDT) readings, design pressure, temperature, service, and leak mechanism (pinhole, corrosion groove, flange blow-out, etc.).

Landing-area validation: Landing areas must be on sound parent metal, clear of weld crowns and heavy scale. Surfaces are cleaned and sanded to bare steel, so measurements are not biased by deposits. During the Design Calculation phase, these landing areas are assumed to have less wall thickness due to general wall loss resulting in an increase of the safety factor of the design.

Accurate dimensional survey: Calibrated outside diameter calipers, radius gauges and digital tape are used. Every key dimension is taken independently by both technicians and cross-checked before the client countersigns the survey sheet.

Risk screening: The engineering team screens the data for elevated risks, for example: cracked studs, chloride stress-corrosion potential on 300-series stainless, or excessive weight on unsupported piping, and may insist on extra NDT or temporary supports before proceeding.

Engineering Design

Clamp designs are governed by recognised industry specifications for online leaksealing devices, ASME PCC2¹ Article 3.12 (Mechanical Clamp Enclosures), ASME BPVC² Section VIII Division 1 principles for pressure vessels, ISO/TS 24817³, and ASME PCC2 Article 4 (for composite or filled repairs), as well as Beruseal internal standards.

Configuration selection: Based on the survey, engineers select a full enclosure split sleeve, surface flange clamp or insert clamp. Unless specifically waived, designs include restraint strongbacks capable of reacting axial line force in the event of a throughwall rupture.

Pressure-area and bolt sizing: Finite element or closed-form analysis converts line and injection pressures to required bolt preload. Torque values and tightening sequence are delivered on the certified drawing issued to the site manager and site technicians.

Material selection: Clamp housings are normally fabricated from carbon steel or stainless-steel plates selected to match the host pipe grade and service conditions. High-strength alloy-steel studs (e.g., ASTM A193 B7 or A320 L7 grades) are paired with compatible heavyhex nuts. Sealing systems, whether elastomer rings, injectable compounds, or cavity-filling resins, are matched to the conveyed medium (hydrocarbon, steam, utility gas) and design temperature.

Quality package: A unique job number that links drawings, weld maps, NDT plan, and the Inspection Test Plan (ITP) that will track every hold-point through manufacturing.

Manufacturing and Quality Assurance

Fabrication is conducted under a certified ISO 9001:2015⁴ quality-management system, with welding quality requirements satisfying ISO 38342⁵. Welders and welding procedures are qualified in ASME IX⁶. Acceptance criteria for welded joints follow ISO 5817⁷ (Level B unless otherwise specified), ensuring consistent workmanship across all devices.

Traceable materials: All plates, forgings and studs arrive with mill certificates and heat numbers are photographed and logged on the Material Profiling Checklist.

In-process QC:

• Groove machining: seal grooves are CNC-cut and signed off before welding to mitigate post-weld distortion.

• Fit-up inspection: tack-welded halves are dimensionally checked, then welded under a qualified WPS and PWHT regimen if required.

• NDT: visual, MPI/UT and radiography are witnessed by QC and the Authorized Inspection Agency (AIA), if required. Non-conformances trigger mandatory repair and re-test cycles.

Final acceptance: After blasting and coating, the enclosure receives a stainless nameplate and Beruseal serial number before release.

Site Deployment

1. Permit & safety setup. A job-specific Permit to Work is issued, barricading, signage and an emergency escape route are established. All personnel wear task-specific PPE and complete a toolbox talk.
2. Prefit checks. The pipe is visually inspected for new damage, the temperature is confirmed within the design envelope, and surfaces around the leak are degreased and wire-brushed to bare metal.
3. Clamp fitup. Using certified lifting slings or chain blocks, if necessary, the two clamp halves are aligned around the pipe. Fitup bolts hold the halves while permanent studs are inserted finger tight.
4. Controlled torquing. Studs are tightened in a four-stage, star-pattern sequence (30 % / 60 % / 90 % / 100 % of final torque) with calibrated hydraulic wrenches. The final torque is recorded on the installation sheet.
5. Restraint installation. Where specified, axial strongbacks or pipe cradles are installed and torqued before any sealing compound is introduced.
6. Port management. Vent and injection ports are verified open, gauges are zeroed.
7. Compound injection. Injection starts at the port furthest from the leak at a pressure 10–20 bar above line pressure (never exceeding 350 bar). Ports are plugged sequentially as the product appears to drive the seal front toward the defect until a full pressure hold is achieved.
8. Optional cavity fill. For extended service, the same elastomer-based sealing compound used in the primary groove is injected into the void cavity through the ports.
9. Verification & signoff. The cavity gauge is monitored for 15 minutes, if stable, insulation is reinstated, the work area is cleaned, and the installation QC sheet is signed by Beruseal and the client representative.

Post-Installation Monitoring and Maintenance

Proactive monitoring ensures the device remains leak-tight for its intended lifespan:

1. 24-hour pressure hold. The cavity gauge is left pressurized to line pressure (or up to 5 bar higher) and checked at 1 h, 4 h, and 24 h. Any drop greater than 2 bar prompts investigation.
2. Hot retorque. On lines operating above 120 °C, bolt preload is rechecked and, if necessary, retorqued once the clamp has equilibrated at temperature for 24 h.
3. Routine inspections. For the first month, visual checks and gauge readings are logged weekly; thereafter they follow the plant’s monthly piping walkdown schedule.
4. Reinjection criteria. A cavity pressure drop >5 bar or visible sweating at the leak edge triggers controlled reinjection. A maximum of three reinjections is permitted over the clamp’s lifetime, each documented in the TLR Monitoring Log.
5. Shutdown removal or rerating. At the next major outage, the clamp may be removed and the spool replaced. If access is constrained, the enclosure can be rerated as permanent once NDT confirms no further wall loss and engineering signs off a stress check.
6. Documentation archiving. All monitoring logs, torque sheets and reinjection tickets are appended to the original data pack and archived for five years.

¹ASME (2022) PCC-2: Repair of Pressure Equipment and Piping. New York: American Society of Mechanical Engineers.
²ASME (2023) Boiler and Pressure Vessel Code: Section VIII – Rules for Construction of Pressure Vessels, Division 1. New York: American Society of Mechanical Engineers.
³ISO (2015) ISO/TS 24817: Petroleum, Petrochemical and Natural Gas Industries — Composite Repairs for Pipework — Qualification and Design, Installation, Testing and Inspection. Geneva: International Organization for Standardization.
⁴ISO (2015) ISO 9001:2015 – Quality Management Systems — Requirements. Geneva: International Organization for Standardization.
⁵ISO (2021) ISO 3834-2: Quality Requirements for Fusion Welding of Metallic Materials – Part 2: Comprehensive Quality Requirements. Geneva: International Organization for Standardization.
⁶ASME (2023) ASME BPVC Section IX: Welding and Brazing Qualifications. New York: American Society of Mechanical Engineers.
⁷ISO (2014) ISO 5817: Welding — Fusion-welded Joints in Steel, Nickel, Titanium and their Alloys (Beam Welding Excluded) — Quality Levels for Imperfections. Geneva: International Organization for Standardization.