Borescopes for Refinery, Pipeline and Vessel Inspection
For the oil and gas industry we supply borescopes and videoscopes used to find corrosion and to inspect welds. Because the inspection is made through an existing opening, a vessel or a line can be examined internally without being cut into.
We also carry out the inspection ourselves, at the customer's own site. One of our technicians passes the probe through the manways, nozzle stubs and tube ends that are open at the time, and records what is inside them.
Refineries, gas plants and chemical works are built from closed volumes. Pipe runs, pressure vessels, columns, heat exchangers and storage tanks all do their work sealed, and a fault inside them usually begins as a mark on a metal surface. The difficulty has never been knowing what to look for. It has been reaching the surface in order to look at it.
The instrument comes in three families and a process plant has use for all of them: borescopes, fiberscopes, which carry the image back along a bundle of fine glass fibres, and videoscopes, which put the camera itself at the tip. What they get pointed at varies less from one site to the next than you might expect. Condenser tubes take up a great deal of the work, and so do the tube bundles inside heat exchangers, pipelines, and the steam and power turbines that drive the big machines and generate the site's own electricity.
Welds get their own attention. Seen from the bore side, a root run can show lack of penetration, a gap where fusion failed, undercut along the toe, or a crack running with the bead or across it. Cracking that begins on the inside surface is exactly the kind an external inspection will not find. Then there is everything that is simply in the way. Fouling and scale narrow a tube and change how it carries heat, debris is left behind after maintenance more often than anyone admits, a demister can collapse, and refractory can break away from a wall in sheets.
Articulation is what makes a probe steerable. A tip that bends under the operator's control can be turned to face a wall, guided around a bend, or pointed back at the underside of a weld. Without it, the probe sees whatever happens to be in front of it. Light is the constraint people forget: a closed vessel is completely dark, and both the illumination and the returning image have to travel the length of the probe, so a narrower tube carries less of each. Choosing well usually means taking the largest probe the opening will genuinely accept rather than the smallest one that will fit.
The alternative to a remote visual inspection is entry, and entry is a project of its own. The equipment has to be isolated, drained, purged and gas tested, a permit has to be raised, and a standby team waits outside while somebody works in a confined space. Radiography answers a different question, and it clears the area of people for as long as the source is out. A borescope answers one question well: what does this surface look like today. It gives that answer while the plant around it is still assembled.
We also carry out the inspection ourselves, at the customer's own site. One of our technicians passes the probe through the manways, nozzle stubs and tube ends that are open at the time, and records what is inside them.
Refineries, gas plants and chemical works are built from closed volumes. Pipe runs, pressure vessels, columns, heat exchangers and storage tanks all do their work sealed, and a fault inside them usually begins as a mark on a metal surface. The difficulty has never been knowing what to look for. It has been reaching the surface in order to look at it.
Where the probe goes in
Process equipment has more openings than people expect. A heat exchanger is entered at the tube ends once the channel head is removed. A vessel has manways and nozzle stubs. A line can be reached at a flange joint, at a valve body, or through a small connection left in place for instruments. Fired heater tubes are examined from the header boxes, and a storage tank through the openings in its shell and its roof. The opening decides everything after it, because it fixes how far the probe must travel, how tight the first bend will be, and whether the operator will be looking straight ahead or sideways at a wall.The instrument comes in three families and a process plant has use for all of them: borescopes, fiberscopes, which carry the image back along a bundle of fine glass fibres, and videoscopes, which put the camera itself at the tip. What they get pointed at varies less from one site to the next than you might expect. Condenser tubes take up a great deal of the work, and so do the tube bundles inside heat exchangers, pipelines, and the steam and power turbines that drive the big machines and generate the site's own electricity.
Corrosion, welds and obstructions
Corrosion is the usual answer, and it does not have a single appearance. General corrosion thins a wall evenly and leaves a dull, roughened surface. Pitting attacks small areas and can run deep while the metal around it stays sound. Corrosion under a deposit hides beneath scale, so the deposit itself is part of the evidence. Erosion appears where the flow changes direction, on the outside of elbows and downstream of orifices, and the surface it leaves is smooth and undercut rather than rough.Welds get their own attention. Seen from the bore side, a root run can show lack of penetration, a gap where fusion failed, undercut along the toe, or a crack running with the bead or across it. Cracking that begins on the inside surface is exactly the kind an external inspection will not find. Then there is everything that is simply in the way. Fouling and scale narrow a tube and change how it carries heat, debris is left behind after maintenance more often than anyone admits, a demister can collapse, and refractory can break away from a wall in sheets.
Diameter, length and direction of view
Three measurements decide whether an inspection is possible at all. The insertion tube has to be narrower than the opening and narrower than the tightest part of the path behind it. The working length has to exceed the distance to the far end of whatever is being examined. And the direction of view has to match the target, because a forward view shows what lies along a bore while a side view shows the wall of one.Articulation is what makes a probe steerable. A tip that bends under the operator's control can be turned to face a wall, guided around a bend, or pointed back at the underside of a weld. Without it, the probe sees whatever happens to be in front of it. Light is the constraint people forget: a closed vessel is completely dark, and both the illumination and the returning image have to travel the length of the probe, so a narrower tube carries less of each. Choosing well usually means taking the largest probe the opening will genuinely accept rather than the smallest one that will fit.
The alternative to a remote visual inspection is entry, and entry is a project of its own. The equipment has to be isolated, drained, purged and gas tested, a permit has to be raised, and a standby team waits outside while somebody works in a confined space. Radiography answers a different question, and it clears the area of people for as long as the source is out. A borescope answers one question well: what does this surface look like today. It gives that answer while the plant around it is still assembled.
