The CorrView ® monitor offers significant advantages to any property manager or plant operator by providing a more realistic estimate of actual corrosion activity, as well as by allowing far more extensive monitoring coverage. It also provides a benefit to those water treatment professionals dedicated to providing the highest level of service to their clients.

     The major advantage of CorrView ®, of course, is its fundamentally simple, low cost, and maintenance free design. Of its many features, the fact that it is a totally self contained corrosion monitoring device, and simple to install virtually anywhere, extends the option of corrosion monitoring to important areas never before possible, nor even considered. Read about some of CorrView's ® advantages.


     CorrView ® is a new product - having recently been awarded a United States Patent. It was specifically invented in response to the high incidence of corrosion produced piping failures seen at many New York City high rise office buildings and elsewhere. The major purpose in its design was to produce a simple and low cost method of better corrosion monitoring; one which, by definition of its simplicity, would extend an awareness of common corrosion problems and save valuable equipment and expense.

     While such corrosion problems are, in most cases, produced due to a lack of adequate water treatment protection, they are often unnecessarily allowed to develop into more serious forms due to inaccurate monitoring methods, or a total lack thereof. Years of performing ultrasonic piping investigations has allowed CorrView International to document the fact that by the time most problems are finally discovered, substantial damage has already taken place.


     While various other methods such as ultrasonic testing, linear polarization resistance, spool pieces, corrosion coupons, and metallurgical sampling do offer excellent testing options, only CorrView ® offers a cost effective and long term monitoring solution for many applications.

     The below listing offers some suggested applications for CorrView ®, and highlights specific problem areas within each application. Further detail for the most common applications, and recommendations on its use, is available at the above navigation bar.

     We raise these areas of concern based upon our 25 years of experience providing chemical water treatment and ultrasonic pipe testing at some of the largest New York City building properties, and elsewhere throughout the United States. See Technical Bulletin # C-10 regarding some common corrosion trends.


 This is the number one problem area for most building owners and plant managers due to the many aggressive forces at work. Condenser or open water systems suffer from the combined effects of an inherently higher corrosion rate, a totally oxygenated environment, airborne particulates, sunlight, and a constant microbiological loading.

Further compounding the problem is more corrosion susceptible steel, less effective chemical and microbiological inhibitors, less tolerant engineering design, and greater operating demands. Together, this often produces higher than acceptable corrosion rates and deep pitting damage which may vary greatly according to the location within the piping system.

The following areas traditionally show higher corrosion activity, and are all recommended for closer monitoring:
  • By-pass lines
  • Long horizontal runs
  • Roof level piping
  • HVAC units which may be shut down
  • Drained lines
  • Dead end areas
  • Smaller run-out piping to HVAC units
  • Lowest floor piping
  • Low flow areas
  • Return lines
  • Mud legs or dead legs
  • Small diameter threaded pipe
  • Alternating equipment piping
  • Future lines
  • Terminated or abandoned piping



Chill water piping can usually be found having a low to moderate corrosion rate. Only under unusual circumstances are problems ever found at its interior.

A common source of high corrosion rates often exist in colder climates where exposed coils are freeze protected over the winter season using glycol. In addition to the partial draining of the pipe, glycol offers an abundant food source to any microorganisms present, and can create a serious MIC condition if allowed to continue. Regular chemical cleanouts and sterilizations are advised in such cases.

Also a common problem in colder climates is the direct connection of condenser water and chill water lines to provide free cooling. In all examples, the strainers allow substantial dirt and debris to enter and then settle into the closed system. All microorganisms will easily pass through the filter as well. Problems therefore develop at the lower floors and at long horizontal runs. Plate and frame heat exchangers are clearly preferred as a free cooling method.

Even under the best corrosion conditions, chill water systems will still produce a substantial volume of rust deposits over many years. This corrosion product accumulates to produce a heat transfer loss, and in the worst cases - under deposit corrosion in areas where the iron oxide deposit settles. View a table of rust volume created for various corrosion rates.

While not possible to actually monitor except visually, cold water piping also suffers from the effects of external corrosion attack due to the failure to adequately insulate the pipe from the migration of area moisture onto its cold surface. In many examples, wall loss occurring due to external moisture condensation will far outweigh that at the pipe's interior surface.

The following areas traditionally show slightly higher corrosion activity, and are recommended for closer monitoring:
  • By-pass lines
  • Long horizontal runs
  • Drained lines
  • Dead end areas
  • Run-out piping to HVAC units
  • Lowest floor piping
  • Mud legs or dead legs
  • Small diameter threaded pipe
  • Alternating equipment piping
  • Future lines
  • Terminated piping



Most closed systems operate under relatively low corrosion conditions. This usually begins to accelerate after 10 or more years of service with the accumulation of interior deposits. Hot water systems traditionally corrode at under 0.5 MPY, other closed and secondary systems at near 1 MPY.

A failure to chemically clean a closed system every five years and provide side stream filtration is often cited as the reason for a corrosion problem. Microbiological contamination is less likely to exist than for an open condenser water system, but always possible. See Technical Bulletin # W-1 regarding the use of side stream filtration to maintain clean closed systems.

The same areas of concern for a chill water system also exist for most closed systems, and the following are recommended for closer monitoring:
  • By-pass lines
  • Long horizontal runs
  • Drained lines
  • Dead end areas
  • Run-out piping to HVAC units
  • Lowest floor piping
  • Mud legs or dead legs
  • Small diameter threaded pipe
  • Alternating equipment piping
  • Future lines
  • Terminated and abandoned piping



Fire sprinkler piping corrodes at a rate generally dependent upon the amount of water flowing through it. For systems where the pipe is left filled for decades, it is common to measure perhaps 20 mils of total wall loss and no pitting. This is because a small degree of corrosion takes place, the oxygen is depleted, and the corrosion process virtually ceases.

Where a fire sprinkler system is extended and modified, or constantly drained and filled, substantial wall loss can occur at a rate similar to an untreated open water system. A small undetected leak at a fire sprinkler system, because of the constant influx of fresh water, can destroy the entire piping system in under 10 years.

Thin wall schedule 10 pipe, now commonly used for fire sprinkler service, is especially susceptible to corrosion attack, and offers little available loss of wall thickness before producing a leak. Most of the failures of sprinkler piping systems we have seen have been primarily due to the use of schedule 10.

Preaction fire systems can suffer greatly due to their being temporarily filled with water during hydrostatic testing and then drained. The use of galvanized pipe does not offer a total solution, and such systems can fail within a few years under certain conditions. Where the galvanized pipe is not of top quality, the coating fails - producing accelerated under deposit corrosion that can bore through pipe wall in as little as two years.

The following areas can exhibit higher corrosion activity, and can be recommended for closer monitoring:
  • Pipe having any water flow activity
  • Long horizontal runs
  • Fire department test lines
  • Frequently drained lines
  • "Sweating" fire sprinkler lines
  • Preaction "dry" piping
  • Galvanized pipe
  • Thin wall schedule 10 pipe

Domestic water problems are greatly dependent upon the type of pipe material installed. Galvanized piping, which is commonly used, suffers greatly once the galvanizing finish wears away and random areas of under deposit corrosion develop. In extreme cases, deposits can accumulate sufficiently to cause a water flow problem.

Deposits are typically most severe at lower floor areas of the system and at horizontal runs, but should be expected to exist throughout the system to some degree.

Brass pipe is relatively unseen today except for older properties. It corrodes very slowly and evenly than steel. Brass is more likely to fail due to dezincification of the metal over decades, than due to a wall loss problem caused by corrosion.

Copper pipe is increasingly used for domestic water systems due to the recognized problems with galvanized pipe. Except for aggressive local water, low pH conditions, microbiological activity, or a cell induced corrosion problem, copper pipe will usually provide long service life.

Only a galvanized steel domestic water line would warrant corrosion monitoring. In such cases, some areas to consider would be:
  • Long horizontal runs
  • Frequently drained lines
  • Bottom of the piping system
  • Thin wall schedule 10 pipe

Corrosion under insulation is a very common problem generally dependant upon a combination of water temperature and area humidity. In most cases, the fiberglass insulation applied is insufficient to prevent the migration of moisture to the pipe - thereby opening a second front for corrosion to attack the pipe. See Technical Bulletin # P-6 for more about the threat of corrosion under insulation.

While CorrView ® cannot offer any benefit in this area, other technologies exist to "view" through the insulation for such problem areas. No regular monitoring devices or methods apply. Our best recommendation is to periodically remove sections of any cold water pipe insulation in the following areas for visual inspection.

Supply side piping, extremely cold temperature services, and areas of high humidity, especially where cold water pipe may run through a steam room, for example, are high priority areas to check every few years. Protecting the pipe with a high solids protective coating is always recommended.
  • High humidity areas
  • Mechanical rooms
  • Steam room areas
  • High traffic areas
  • Colder supply lines
  • Horizontal lines
  • Outdoor locations
  • Areas of damaged insulation
  • Brine or ammonia systems


     Overall, CorrView ® offers substantial benefits to anyone responsible for HVAC or process piping systems. While not a single source corrosion monitoring solution, its low cost and simple operation easily extends its use into areas never before addressed. This, by definition, greatly improves system reliability, as well as the chance of identifying a corrosion problem before it becomes a major maintenance issue.