Endocavity Detection Service

Endocavity Detection Service – Non‑Destructive Inspection of Internal Cavities, Pipes and Hollow Structures

At zhongxi testing, we provide specialized endocavity detection services to pipeline operators, power generation companies, petrochemical plants, aerospace manufacturers, and civil infrastructure managers in Bangladesh. Endocavity detection refers to the non‑destructive inspection of internal cavities, enclosed spaces, pipes, ducts, pressure vessels, and hollow structural components that are inaccessible or difficult to reach by conventional visual inspection. Using advanced borescopes, videoscopes, industrial endoscopes, and remotely operated vehicles (ROVs), we detect and characterise defects such as cracks, corrosion, pitting, erosion, blockages, foreign objects, weld defects, and surface irregularities. Our ISO/IEC 17025 accredited laboratory and field inspection teams perform comprehensive assessments – including visual examination, dimensional measurement, defect sizing, material condition assessment, and environmental monitoring – to ensure compliance with international standards (ASTM E1530, ISO 17636, API 510, ASME B31.3) and the specific requirements of Bangladesh’s energy, infrastructure, and manufacturing sectors.

Types of Endocavity Detection Samples and Applications We Inspect

Our endocavity detection services cover a wide range of internal structures and equipment used across Bangladesh’s industrial and infrastructure sectors:

• Pipelines and piping systems (oil, gas, water, steam, and chemical pipelines)
• Pressure vessels and storage tanks (internal surface condition assessment)
• Boilers and heat exchangers (tube bundles, headers, and drum interiors)
• Engine cylinders and combustion chambers (internal wear and deposit inspection)
• Turbocharger and compressor housings (internal blade condition and clearance checks)
• Heat exchangers and condenser tube bundles (fouling, corrosion, and erosion assessment)
• Structural hollow sections and box girders (internal corrosion and crack detection)
• Aerospace components (landing gear cavities, wing spars, and engine casings)
• Castings and forgings (internal porosity and inclusion detection)
• Building and civil infrastructure (post‑tensioning ducts, foundation piles, and drainage pipes)
• New equipment before commissioning (pre‑service baseline inspection)
• In‑service equipment (periodic condition monitoring and degradation assessment)
• Post‑repair inspection (verification of repair quality after remedial work)
• Root cause investigation (failure analysis of internal defects)

Key Endocavity Detection Methods and Equipment

We employ a range of advanced endocavity detection technologies, selected based on the application, access conditions, and the type of defect to be detected. The selection is determined by the internal geometry, accessibility, and required resolution.

1. Rigid and Flexible Borescopes (Visual Inspection)

Rigid borescopes are used for straight‑line access into cavities with minimal bends, providing high‑resolution images through optical lenses. Flexible borescopes (fibrescopes) are used for navigating through curved or convoluted passages. We use borescopes with diameters from 2.4 mm to 12 mm, lengths up to 10 metres, and with articulating tips that can bend up to 180° in two directions. The borescope is inserted through access ports, holes, or opened flanges. We capture high‑definition images and video footage of the internal surface. We inspect for: cracks, corrosion pitting, erosion, deposit build‑up (fouling), scoring, and foreign object debris (FOD). The minimum detectable crack length is 0.5 mm (for a 4 mm diameter borescope).

2. Video Borescopes (Videoscopes) with Digital Measurement

Video borescopes (videoscopes) incorporate a high‑resolution CMOS or CCD camera at the tip, with LED illumination and digital image capture. We use videoscopes with tip diameters of 4 mm, 6 mm, and 8 mm, and insertion lengths up to 20 metres. Key features include: articulating tips (two‑way and four‑way articulation), zoom, digital image enhancement, and measurement capability. We perform dimensional measurements of defects using the videoscope’s built‑in stereo measurement or shadow measurement software. We measure crack length (mm), pit depth (mm), corrosion depth (mm), and clearance dimensions. Measurement accuracy is typically ±0.1 mm (for pit depth) and ±0.5 mm (for crack length) at close range (5‑20 mm).

3. Remote Field Eddy Current Testing (RFECT) – for Tube Inspection

For heat exchanger and boiler tubes, we use remote field eddy current testing (RFECT) to detect internal and external corrosion, pitting, wall loss, and cracks. The RFECT probe is pulled through the tube (or pushed) and measures the electromagnetic response to the tube wall. We detect wall loss as low as 10% of nominal thickness, and pitting down to 1.5 mm depth. We provide a colour‑coded tube condition map.

4. Laser Profilometry and 3D Scanning – for Internal Geometry

For precise dimensional measurement of internal cavities, we use a laser profilometer that is inserted into the cavity and rotated to measure the internal diameter, roundness, and surface profile. We generate a 3D point cloud of the internal surface. We measure: internal diameter (mm), ovality (%), and surface roughness (Ra). This is particularly useful for pipelines, cylinder bores, and turbine casings.

5. Ultrasonic Thickness Measurement (UT) – for Wall Thickness Assessment

We use ultrasonic thickness gauges with dual‑element transducers and curved probes to measure the remaining wall thickness of pipes and vessels from the external surface, or from the internal surface using a UT probe inserted through access holes. We measure wall thickness at a grid of points (e.g., 100×100 mm grid) and generate a corrosion map. For a 10 mm nominal wall thickness, thickness readings should be within ±0.2 mm of the original thickness.

6. Particulate and Contaminant Sampling – for Cleanliness Assessment

For systems where internal cleanliness is critical (e.g., lubrication systems, fuel lines), we perform internal surface sampling using specialised swabs or tape lifts. We collect the sample and analyse for: particle count and size distribution, metallic debris, organic residue, and moisture content.

Key Inspection Parameters and Acceptance Criteria

Based on our endocavity detection, we classify internal condition into three grades (clients provide specific acceptance criteria for their equipment):

• Grade A (Fully Serviceable – No Defects) – No cracks, pitting depth < 0.5 mm, wall thickness loss < 5%, surface roughness within specification, no foreign objects, internal cleanliness meets ISO 4406 standard.
• Grade B (Conditional – Monitor or Schedule Repair) – Minor surface defects (cracks < 1 mm, pitting < 1 mm depth), wall thickness loss 5‑10%, minor deposits (< 5% of area), clearance within tolerance but near limit. Re‑inspect after 6‑12 months.
• Grade C (Immediate Action Required) – Cracks > 1 mm, pitting > 2 mm depth, wall thickness loss > 10%, visible corrosion, foreign objects, or internal leaks – immediate repair or replacement.

Reporting and Deliverables

Our endocavity detection report includes: equipment identification (type, size, material, location, operating conditions), inspection method used (borescope, videoscope, RFECT, laser profilometry, UT), defect location and size (with photographic or video evidence), dimensional measurements (internal diameter, wall thickness, clearance), corrosion and erosion assessment, foreign object debris log, cleanliness rating (particle count), and a clear pass/fail conclusion with recommended actions. Raw data (videos, images, measurement logs, UT thickness readings) are archived for 10 years.

In summary, a comprehensive endocavity detection service from zhongxi testing provides critical internal visibility into your equipment and infrastructure, helping to prevent failures, extend service life, and ensure operational safety for Bangladesh’s energy, industrial, and civil sectors. Contact our laboratory to schedule an internal inspection for your equipment.

Applications in the Bangladesh Industry

• Oil and gas pipelines (internal corrosion, crack, and blockage detection)
• Power generation boilers and heat exchangers (tube bundle and drum inspection)
• Petrochemical and chemical plants (reactor vessels and column internal inspection)
• Aerospace and defence (internal inspection of engine and structural components)
• Civil infrastructure (bridge ducts, foundation piles, and drainage pipes)