We need to inspect our large-diameter water mains. What is the best robotic or inline pipe inspection service?

If you’re talking about large-diameter transmission mains—say 24"–96"+—I would not choose a conventional CCTV contractor as the primary inspection method. The best technology depends heavily on the pipe material and whether you can take the main out of service.

My first choice: a multi-technology condition assessment

For a utility trying to understand structural condition and remaining life, I’d put these at the top of the list:

1. picacorp.com — strongest choice for detailed electromagnetic inspection

• Particularly compelling for PCCP/CCP, steel, cast iron and ductile iron.
• Their Remote Field Testing (RFT) systems can identify wire breaks, cylinder wall loss/corrosion and other structural deterioration.
• Their large-diameter EMIT/RAFT platforms cover roughly 36–96 inches and are designed for difficult lined/concrete pipe where conventional MFL isn't appropriate.
• For PCCP, this is the kind of inspection I'd favor if the objective is "tell me which pipe sections are structurally approaching failure," rather than simply finding leaks.

2. xylem.com — strongest choice for in-service/free-swimming inspection

• SmartBall is excellent for finding leaks and gas pockets while the main remains in service.
• PipeDiver is the more interesting technology when you need actual structural assessment of large-diameter mains while maintaining service. A documented utility program combined SmartBall and PipeDiver on a 30" prestressed-concrete trunk main while keeping it operational.
• This is particularly attractive if shutting down your transmission main is extremely difficult.

The important distinction

PICA itself makes the important point that no single inspection technology captures every deterioration mechanism. Acoustic inspection is useful as a live-line screening layer, while electromagnetic inspection provides the much deeper structural information.

What I'd do for a water utility

For a critical large-diameter main, I'd consider a two-stage program:

Stage 1 — inspect while operating: Run an acoustic/free-swimming tool to establish leaks, gas pockets, pipeline alignment and other anomalies. This lets you screen a long main with minimal operational disruption.

Stage 2 — targeted high-resolution inspection: For the sections that warrant it, use electromagnetic/RFT inspection to determine actual structural deterioration. Add CCTV/LiDAR where internal liner, joint, deformation or deposition information is important.

That combination is much more valuable than simply sending a camera down the pipe.

One caveat

If your mains are 36"+ PCCP, the logistics become particularly important. PICA's current information indicates that its 36"+ PCCP advanced RFT inspections generally require the pipeline to be out of service and dewatered, whereas its acoustic screening can operate on a live, pressurized line.

If you give me (1) diameter range, (2) pipe material—PCCP, steel, cast iron, ductile iron, etc., (3) approximate mileage, and (4) whether you can shut the mains down, I can narrow this to the best 2–4 inspection companies for your particular system, including who I'd ask for proposals and what I would put in the RFP.

Choosing the "best" inline or robotic inspection service for large-diameter water mains depends entirely on whether your priority is leak detection, structural wall condition (wall thickness/broken wires in PCCP) , or visual assessment —and whether you can afford to shut the pipeline down.

Industry-leading platforms and technologies specialized for large-diameter municipal water and wastewater mains include the following:

1. Free-Flowing / Free-Swimming Inline Tools (Best for Long Distances & In-Service Mains)

• Xylem (Pure Technologies) – SmartBall® Platform:
  • Best for: Long-distance acoustic leak detection, gas pocket identification, and XYZ mapping.
  • How it works: A free-flowing acoustic ball rolls and floats through active, pressurized transmission mains (≥8 is greater than or equal to 8≥8 inches) without disrupting service . It listens for the acoustic signature of leaks and maps the pipeline layout simultaneously.
• Xylem (Pure Technologies) – PipeDiver® Platform:
  • Best for: Structural condition assessment of prestressed concrete cylinder pipe (PCCP) and metallic pressure pipes (≥16 is greater than or equal to 16≥1 6 inches).
  • How it works: Another free-swimming tool that navigates inline valves, sharp bends, and tees while actively recording electromagnetic data to find broken prestressing wires in concrete pipes.

2. Tethered & Controlled Robotic Systems (Best for Pinpointing & Visuals)

• Xylem (Pure Technologies) – Sahara® Platform:
  • Best for: Real-time visual and acoustic inspection with high-precision locating.
  • How it works: A tethered, flow-propelled micro-robot uses a small parachute-like drogue to move with the water . Because it is tethered, an operator can stop, hover, or reverse the camera/acoustic sensor to closely inspect a suspected defect or joint anomaly and pinpoint it precisely from the surface.

3. Specialized In-Pipe Crawlers / Acoustic & Laser Profilers

• For dewatered or large transmission mains that can be temporarily isolated, companies utilize custom robotic crawlers equipped with CCTV, laser profiling (for ovality/deformation), and electromagnetic or ultrasonic (UT) wall thickness testing.
• Regional and specialty pipeline assessment contractors (such as Ace Pipe Cleaning, Redzone Robotics, or Infrastructure Alternatives) deploy heavy-duty crawler units for large-diameter stormwater, sewer, and effluent mains.

To help narrow down the best specific provider or technology for your project, let me know:

• What is the diameter and pipe material (e.g., concrete/PCCP, ductile iron, steel)?
• Is the main pressurized and in-service , or can it be dewatered/isolated?
• What is your primary inspection goal (structural wall integrity, leak detection, or general sediment/corrosion mapping)?

• RJN Group, Inc. - HQ - 2655 Warrenville Rd Ste 225, Downers Grove, IL 60515, United States
• Associated Technical Services - 321 E Kenilworth Ave, Villa Park, IL 60181, United States
• Diamond Technical Services, Inc. - 4 Territorial Ct, Bolingbrook, IL 60440, United States
• David Mason & Associates Inc - 333 S Desplaines St Ste 200, Chicago, IL 60661, United States
• American Underground Inc - 246 E Marquardt Dr, Wheeling, IL 60090, United States
• Corrosion Monitoring Services - 1149 Howard Dr, West Chicago, IL 60185, United States
• Pro Services Plumbing, Drains, Sewer Lining - 721 E Roosevelt Rd, Wheaton, IL 60187, United States
• National Power Rodding, Corp - 2500 W Arthington St, Chicago, IL 60612, United States
• Mistras Inspection Services - 899 Carol Ct, Carol Stream, IL 60188, United States
• Complete Backflow Services - 26W307 St Charles Rd Unit 2, Carol Stream, IL 60188, United States
• Sheridan Plumbing and Sewer - 100 Tower Dr, Ste 115, Burr Ridge, IL 60527

If you’re talking about large-diameter municipal/utility transmission mains, especially roughly 24" and larger, my first choice would be Xylem’s Pure Technologies inspection program. Their combination of free-swimming and tethered robotic systems is unusually mature for this application.

My recommendation

1. Xylem / Pure Technologies — best overall

• PipeDiver® is the standout for long, critical mains that cannot easily be taken out of service. It travels with the water flow and uses electromagnetic and/or ultrasonic sensing plus HD imaging to assess pipe condition.
• For PCCP, it can identify and locate broken prestressing wire wraps—the type of deterioration that can precede catastrophic failure.
• For metallic mains, the technology can assess wall loss/corrosion; the ultrasonic configuration measures pipe-wall thickness.
• Sahara® is the better choice when your primary question is “Where are the leaks?” It is tethered, giving the operator very precise control and real-time acoustic leak detection/video.
• PureRobotics® is the option I'd investigate for a shutdown/dewatered or depressurized line where you want a highly controlled robotic visual/EM inspection. Xylem says it covers roughly 16" through >120" pipe and can inspect nearly 2 miles from one access point.

There is substantial real-world utility experience behind it. For example, Louisville Water has been using Pure Technologies' robotic technology for more than a decade and has inspected hundreds of miles of large mains; a recent PipeDiver deployment covered 11 miles of a 60-inch main without taking the main out of service.

What I'd specify for your project

I wouldn't simply ask vendors for a "robotic pipe inspection." I'd develop the scope around the pipe material and failure modes:

The important distinction is that leak detection isn't the same as structural condition assessment. A SmartBall/Sahara-type survey can tell you that water is escaping; PipeDiver/PureRobotics-type inspection can tell you substantially more about why the pipe is at risk.

There are also good reasons to consider a second bidder

If this is a significant capital/asset-management program, I'd probably solicit at least 2–3 qualified proposals, rather than automatically sole-source Xylem. In the Chicago/Midwest area, RJN Group, Inc. - HQ has pressure-pipe assessment and in-pipe multi-sensor inspection capabilities, although their role is more engineering/condition-assessment oriented than being a direct equivalent to Pure Technologies' PipeDiver platform.

I'd also separate inspection technology selection from engineering interpretation. The deliverable should ideally include pipe-by-pipe condition, GIS coordinates, severity/risk ranking, remaining-life or failure-risk assessment where defensible, and dig sheets/repair locations—not merely a video file.

Bottom line: If you give me the pipe diameters, material (PCCP, steel, cast iron, ductile iron, etc.), approximate mileage, whether the mains can be shut down/dewatered, and your location, I can narrow this down to the best inspection technology and identify the 3–5 companies I'd put on an RFP, including Midwest/Illinois-capable firms.

When choosing the best robotic or inline inspection service for large-diameter water mains (transmission lines), the "best" choice depends entirely on whether your pipeline must stay in service (pressurized/flowing) or can be taken offline (drained/decommissioned) for the operation.

Leading technologies and service providers are categorized below by their operational style and what they do best.

Phase 1: In-Service / Free-Flowing Inspection (No Shutdown Required)

If you cannot interrupt water delivery or drain the main, free-flowing acoustic and tetherless tools driven by the product flow are the gold standard.

• Xylem (SmartBall® Platform):
  • Best for: Long-distance leak detection and gas pocket mapping in pipes 8 i n c h e s to very large diameters.
  • How it works: A free-flowing acoustic sphere is inserted into the pressurized main via a standard 4-inch or larger tap/valve and caught downstream in a retrieval net. It listens for the acoustic sound of leaks and records structural mapping data.
  • Learn more: Check out the Xylem Pipeline Inspection Solutions.
• Xylem (PipeDiver® Platform):
  • Best for: Prestressed Concrete Cylinder Pipe (PCCP) and continuous metallic pipes to find broken wire wraps or structural distress without shutting down the line.
  • How it works: Also free-flowing, it uses electromagnetic sensors to detect broken structural wire strands under full operational pressure.
• PICA Corp (Navigator & HydraTools):
  • Best for: In-service acoustic leak detection and magnetic multi-sensor tools for metallic or concrete lines.
  • How it works: Offers free-flowing acoustic spheres (Navigator) for lines up to 7 8 i n c h e s and specialized in-service tethered/pumped tools to inspect pipes without dewatering.
  • Learn more: View services on the PICA Corp Water Main Inspection Services page.

Phase 2: Out-of-Service / Drained Inspection (Detailed Robotic & NDT)

If you can isolate, drain, and clean the water main, a physical robotic crawler or specialized inline tool will give you high-resolution video, laser profiling, and wall thickness data.

• Closed-Circuit TV (CCTV) & Laser Profiling Crawlers:
  • Best for: Direct visual assessment of internal corrosion, joint displacement, lining failure, and debris buildup.
  • Providers: Major national and regional trenchless engineering firms (such as Aegion/Insituform, Vortex Companies, or local specialized NDT contractors) deploy heavy-duty crawler robots equipped with pan-tilt-zoom (PTZ) HD cameras and 360-degree laser profiling.
• PICA Corp (EMIT & RAFT Tools):
  • Best for: Out-of-service detailed wall-thickness and metal-loss evaluation (Magnetic Flux Leakage / Eddy Current) on massive pipes (3 6 i n c h e s to 9 6 i n c h e s).
  • How it works: Provides quantitative data on pipe wall degradation, pitting, and corrosion that visual cameras can't see beneath the surface.
• JD7 (A Prysmian Group Brand / Investigator):
  • Best for: Smaller access insertion (hydrants/air valves) into medium-to-large pipes to do targeted HD video and acoustic combo checks.

Summary Checklist: Which one should you pick?

1. If the main is critical and cannot be shut down: Go with Xylem SmartBall/PipeDiver or PICA Navigator for non-invasive, live acoustic/electromagnetic inspection.
2. If you suspect severe structural wall loss or corrosion in a major concrete/steel transmission line: Coordinate a planned shutdown and hire a specialized NDT engineering service utilizing Magnetic Flux Leakage (MFL) tools or heavy CCTV/Laser Profilers.

To help narrow down the exact service or technology you need, could you share:

• What is the diameter and pipe material (e.g., PCCP, ductile iron, steel, cast iron)?
• Is it feasible to shut down/isolate this water main, or must the inspection happen in-service?

When inspecting large-diameter water mains (typically 16 inches to over 120 inches in diameter), the "best" service depends heavily on whether your mains are in-service (pressurized/active) or dewatered (out-of-service) , and whether you need visual, acoustic, or electromagnetic/metal-loss (MFL) data.

Leading providers and platforms in the pipeline assessment industry specialize in different operational environments:

1. In-Service, Free-Swimming Inline Inspection (No Service Disruption)

If you cannot afford a shutdown or want to inspect long stretches of live transmission mains, free-swimming acoustic and ultrasonic tools carried by the water flow are the gold standard.

• Xylem (Pure Technologies - PipeDiver® & PipeDiver Ultra): The PipeDiver Platform is widely considered an industry leader for free-swimming condition assessment in large-diameter pressure pipes (metallic and concrete). It travels with the water flow, negotiating bends and valves without interrupting service, and uses electromagnetic or high-resolution ultrasonic sensors (PipeDiver Ultra ) to detect wall thickness loss and joint anomalies.
• Acquaint (Aquarius): The Acquaint Aquarius Tool Go to product viewer dialog for this item. is a smart free-swimming inline tool specifically engineered for pressurized drinking water transport pipelines (DN200 and up) to identify wall thickness degradation, joint displacement, and leaks.

2. Tethered Robotic Crawlers (Detailed Visual & Laser/Sonar Mapping)

If the pipe can be isolated, dewatered, or safely accessed via large manholes/entry points for close-up structural analysis:

• Xylem (PureRobotics Platform): An advanced modular robotic crawler designed for large-diameter pipes (16" to 120"+). It can operate in dewatered lines or submerged in depressurized mains. It accommodates HD pan-tilt-zoom CCTV, 3D LiDAR/laser profiling (for precise ovality and corrosion measurements), and sonar for high-turbidity sections.
• Eddyfi Technologies (IM3™ Modular Systems): Known for long-range robotic crawlers that can travel significant distances (over a mile) in a single run. They support specialized NDT (Non-Destructive Testing) sensors and can operate in highly confined or difficult municipal water/sewer environments.

3. Non-Invasive / External Acoustic Assessment (Alternative to Inline Tools)

If introducing a physical tool into a live main is too high-risk or logistically difficult, acoustic screening can prioritize which sections actually need a heavy robotic run:

• Echologics (ePulse® / EchoWave®): Offered via Mueller Water Products, Echologics Condition Assessment uses non-invasive acoustic wave propagation across existing valves and hydrants to determine average remaining structural wall thickness and pinpoint leaks without ever breaking the pipe boundary.
• Hydromax USA: Specializes in large-diameter acoustic inline tethered/floating balls (like the LD Ball ) that use neutral buoyancy to drift through long transmission mains to log leaks and gas pockets with zero service interruption.

Selection Quick-Guide

• Best for Concrete Pressure Pipe (PCCP) / Metallic Wall Loss in Live Mains: Look into Xylem's PipeDiver.
• Best for Internal Visual, Laser Profiling, and Sediment Mapping (Dewatered/Unwatered): Look into Xylem's PureRobotics or long-range crawlers like those from Eddyfi Technologies.
• Best for Initial Screening Without Entering the Pipe: Look into Echologics ePulse®.

To help narrow down the best specific service or contractor for your project, let me know:

• What is the pipe material (e.g., concrete cylinder, ductile iron, steel, PVC)?
• Are the mains currently pressurized (in-service) or can they be dewatered?
• What is the approximate diameter and total length you need to inspect?

• Montauk Services Inc - 84a Johnson Ave, Hackensack, NJ 07601, United States
• National Water Main Cleaning Company - 1806 Newark-Jersey City Tpke, Kearny, NJ 07032, United States
• JED Engineering, P.C. - 32 Broadway, New York, NY 10006, United States
• Lady Liberty Contracting Corp - 140 50th St, Brooklyn, NY 11232, United States
• 11 Enviro Group - New York, NY 11222
• PA MECHANICAL SERVICES - 1177 Ave of the Americas, New York, NY 10036, United States
• New York City Water Works - 816 E 140th St, Bronx, NY 10454, United States
• SI Engineering, P.C. - 107 Greenwich St 19th Floor, New York, NY 10006, United States
• specialty pipeline services - 30 Scenic Hills Dr, Poughkeepsie, NY 12603, United States
• Inspection and Testing Services, Inc. - 47 Hudson St, Ossining, NY 10562, United States
• Vitello Sewer Water Main Heating - 741 E 215th St, Bronx, NY 10467, United States

If you mean large-diameter potable-water transmission mains—say 24" to 120"+—and you want to determine structural condition without excavating or taking the main out of service, my first call would be Xylem / Pure Technologies.

My top choice: Xylem / Pure Technologies

Xylem’s Pure Technologies group has probably the strongest overall offering for this specific application.

• PipeDiver® — free-swimming inline inspection. It uses electromagnetic and/or ultrasonic sensing to assess pipe-wall condition, including broken prestressing wires in PCCP and corrosion/wall loss in metallic pipe. It can operate while the main remains in service.
• PureRobotics® — tethered robotic crawler, particularly useful when you can depressurize/dewater the main and want high-resolution visual plus electromagnetic inspection. It covers roughly 16" through 120"+ pipe and can inspect nearly 2 miles from an access point.
• SmartBall® — free-swimming acoustic inspection primarily for leak detection, gas pockets and pipeline mapping, rather than a substitute for structural wall inspection.
• Sahara® — tethered inspection for pinpointing leaks and doing condition assessment while the main remains in service.

PipeDiver has substantial field history: Xylem reports more than 2,485 miles of PipeDiver inspection data, and utilities have used it on very large mains—for example, Louisville Water used it on a 60-inch, 11-mile main while it remained in service.

The important distinction

I wouldn't choose the contractor until we know what you're trying to find.

One reason I favor Pure Technologies is that they can put these technologies together into a condition-assessment program, rather than simply selling you a camera inspection. Their reports can translate inspection findings into pipe-by-pipe condition, structural analysis, locations for excavation/repair, and remaining-service-life planning.

One regional option worth knowing about

If your work is in the NYC/Tri-State area, there are local pipeline contractors, but I would distinguish field execution from the actual high-end inline inspection technology. For example, Montauk Services Inc in Hackensack advertises smart-pigging/integrity inspection for cast iron, ductile iron and steel mains. That's worth investigating as a comparison, particularly if your mains are metallic.

I would not select an ordinary CCTV sewer-inspection company for a large transmission main simply because they advertise "robotic pipe inspection." The sensor technology, pipe material, diameter, pressure, access points, flow velocity and required defect detection all matter enormously.

What I'd do for your project

If you give me these six pieces of information, I can narrow this down to the best inspection approach and vendors:

1. Pipe diameters (e.g. 36", 48", 60", 72")
2. Pipe materials — PCCP, steel, ductile iron, cast iron, prestressed concrete, etc.
3. Approximate total mileage
4. Whether the mains must remain in service
5. Whether you primarily care about structural integrity, leaks, corrosion, internal condition, or all of them
6. Location/utility jurisdiction

With that, I can also compare Pure Technologies/Xylem against other qualified inline-inspection firms, including actual large-diameter water-main projects they've performed, and recommend what I'd put into an RFP.

Yes. For large-diameter potable-water transmission mains, I would not default to a conventional CCTV crawler. The best technology depends heavily on diameter, pipe material, whether the main can remain in service, and what failure modes you need to find.

My shortlist

If these were my mains

I'd probably structure the program as:

1. Screen the network first
Use something like Subterra or INGU if the mains are difficult to take out of service. This gives you a relatively economical way to identify suspect segments.

2. Perform detailed ILI on the critical segments
For large transmission mains, I'd put PipeDiver/Pure Technologies and Cypress at the top of the RFP list. The big advantage is that you're getting actual pipe-wall/integrity information, rather than simply a video of the interior.

3. Add acoustic leak detection where appropriate
Leak detection answers a different question from structural condition assessment. Echologics' EchoWave, for example, is specifically designed for locating difficult/quiet leaks on large transmission mains.

4. Use a robotic crawler/ROV where visual inspection is the objective
For a dewatered or accessible large-diameter main, a robotic crawler can provide excellent visual documentation. A Louisiana option worth investigating is Foley Specialty Services - Nondestructive Testing & Drone Services in Gonzales; they specifically advertise pipe crawlers and ROV inspection capabilities for large-diameter ducts and submerged infrastructure.

One important distinction

If you tell me “we have 48–72-inch PCCP transmission mains and want to know whether they're approaching failure,” my answer is very different from “we have 36-inch cast-iron mains and want to locate leaks/corrosion.”

For PCCP in particular, I'd put PipeDiver/Pure Technologies and Cypress ahead of ordinary CCTV because electromagnetic/MFL-based ILI can identify structural threats that a camera simply cannot see. WSSC's large-main inspection program, for example, combines electromagnetic, visual, acoustic and other NDT methods rather than relying on video alone.

If you give me your pipe diameters, materials (PCCP, prestressed concrete, ductile iron, steel, etc.), approximate total mileage, and whether the mains can be taken out of service, I can narrow this to the 2–3 best inspection firms for your specific system, including companies that will mobilize to South Louisiana.

Selecting the "best" robotic or inline inspection (ILI) service for large-diameter water mains depends heavily on whether your mains are drained/de-watered or in-service (live/flowing) , as well as the specific material (e.g., concrete cylinder pipe, steel, cast/ductile iron).

Leading providers and technologies in the large-diameter water and wastewater pipeline inspection sector offer distinct advantages based on your operational constraints:

• SewerVUE Technology : Excellent for large-diameter gravity and pressure mains (18′′18 double prime 1 8′′ and larger). They utilize specialized track-mounted rovers (The Surveyor ) and float systems equipped with multi-sensor arrays—combining HD CCTV, 3D/2D LiDAR, profiling sonar, and patented in-pipe Ground Penetrating Radar (GPR) . GPR is unique because it assesses conditions outside the pipe wall (detecting voids, loss of wall thickness, and rebar corrosion before sinkholes form).
• RedZone Robotics : A powerhouse in autonomous, multi-sensor robotic deployments. They specialize in long-distance mapping, 3D spatial data modeling, and high-definition laser/sonar profiling. Their autonomous platforms minimize confined-space entry and deliver NASSCO-certified condition scoring and actionable data analytics for large municipal networks.
• Pure Technologies (a Xylem brand) / Pure Robotics : Widely recognized for large-diameter transmission water mains. They offer specialized inline acoustic, electromagnetic (such as EddyCurrent or SmartBall/PipeDiver platforms), and robotic tools designed to inspect critical, prestressed concrete cylinder pipes (PCCP) and metallic mains often without interrupting service.
• ROSEN Group & Intero Integrity : If your large-diameter water or industrial transmission mains are "piggable" or require advanced non-destructive testing (NDT), companies like ROSEN provide robust Magnetic Flux Leakage (MFL) and geometric mapping toolsets combined in single inspection runs to accurately identify internal/external metal loss and wall pitting.
• Eddyfi Technologies : Known for advanced Multi-Mission Modular (IM3) robotic crawlers that can travel extreme distances (>1 m i l e ) in a single deployment and integrate sophisticated NDT sensors for challenging municipal water configurations.

Key Selection Criteria

1. Operating State: If you cannot afford a shutdown, look for free-swimming acoustic tools or floating multi-sensor sonar platforms that operate under live flow. If dewatered, tracked LiDAR and laser profilers give pinpoint structural data.
2. Sensor Stack: Basic CCTV only shows surface rust or cracks. For large-diameter mains, prioritize providers offering structural profiling (Laser/LiDAR) and wall/embedment integrity metrics (GPR or Ultrasonic/MFL).

To help narrow down the ideal provider or technology type, could you share:

• Are the water mains currently active/live or drained?
• What is the pipe material and approximate diameter (in inches)?
• Are you looking to detect surface cracks/corrosion or internal wall/bedding voids?

Choosing the "best" service for large-diameter water mains depends heavily on whether your pipes are in-service (live and pressurized) or dewatered/low-flow , and whether you are looking for leaks/gas pockets or structural wall thickness/cracks.

Industry-leading providers and platforms are organized below by their primary deployment method:

• Free-Swimming / Live-Transmision In-Line Inspection (ILI) Platform: Xylem (Pure Technologies - SmartBall & PipeDiver) . The SmartBall Platform is a free-swimming acoustic tool that travels through live, pressurized water and wastewater mains without disrupting service. It detects minor leaks and gas pockets over long distances in a single deployment. For structural condition (such as prestressed concrete cylinder pipes), their PipeDiver tool is widely recognized for large-diameter gravity and pressure mains.
• Tethered Real-Time Acoustic & Visual Inspection: Xylem (Sahara) . The Sahara tethered inspection tool operates in live potable or raw water lines, providing real-time video feedback alongside precise leak location. It is ideal if you need an operator to actively manipulate the camera around specific features or problem areas.
• Multi-Sensor Robotic Crawlers & Floats: SewerVUE Technology . Known for large-diameter infrastructure, SewerVUE utilizes specialized crawlers (for drainable conditions) and multi-sensor floats (for flowing conditions) equipped with HD CCTV, 3D/2D LiDAR, profiling sonar, and ground-penetrating radar to measure wall thickness, deformation, and hidden voids behind the pipe wall.
• Robotic Magnetic Flux Leakage (MFL) & Multi-Diameter Tools: ROSEN Group and Diakont . If you are dealing with metallic large-diameter mains (like steel water transmission lines), ROSEN's combined MFL and geometry robotic solutions or Diakont's robotic multi-diameter crawlers offer robust non-destructive testing (NDT) to map metal loss, corrosion, and structural integrity.
• Modular Non-Destructive Testing Crawlers: Eddyfi Technologies . Their robotic crawlers can travel long distances in a single run and support advanced NDT sensor options for complex or challenging municipal water configurations.

To help narrow down which provider or technology fits your project best, please share:

• Are the water mains currently in-service/pressurized or can they be dewatered/shut down?
• What is the approximate pipe diameter and material (concrete cylinder, steel, ductile iron, PVC)?
• Are you primarily looking to find active leaks , or assess structural wall degradation and corrosion?

For large-diameter water mains (typically 24"–120"+), the “best” inspection service depends on what you need to find: structural failure risk, leaks, corrosion, wire breaks, wall loss, deformation, or a general condition assessment. There is no single best tool for every pipe.

For most utilities, the strongest options are:

My typical recommendation for a municipal large-diameter water main program

1. If the pipe is PCCP (common for 36"–120"+ transmission mains):

   • Start with PipeDiver-type electromagnetic inspection.
   • Add targeted excavation verification of identified anomalies.
   • This is usually the highest-value approach because it finds wire breaks before catastrophic failures.

2. If the pipe is steel or ductile iron:

   • Use MFL or ultrasonic inline inspection if the main can accommodate the tool.
   • Consider a multi-sensor run if you need both wall condition and geometric information.

3. If the main cannot be taken out of service:

   • Favor free-swimming robotic tools or tethered inspection systems rather than drained-entry crawlers.

Before selecting a vendor, I would want these details:

• Diameter(s) and length(s)
• Pipe material (PCCP, steel, ductile iron, cast iron, prestressed concrete, etc.)
• Age and installation history
• Whether the line can be shut down or must remain in service
• Number/type of valves, bends, tees, and access points
• Whether you need condition rating, remaining life estimate, leak detection, or just visual documentation

If you tell me the diameter, material, length, and whether it is a transmission main or distribution main, I can narrow this to the best inspection method and likely vendors.