Technical and trial details
For engineers, and anyone who wants the full picture. To see if it fits your building, start with 2 photos.
Which model fits
NMR Pipetector is built for closed-loop HVAC heating hot-water and chilled-water piping, including loops above 70°C (158°F) and loops with corrosion inhibitors or glycol.*1
What pipe types and sizes does it work on?
It mounts on iron and steel pipe, including black steel and galvanized steel pipe, and on copper pipe. Models range from about 1 to 80 inches (25 mm to 2,000 mm); for the Round 1 trial we focus on the 3- to 20-inch mains common in commercial buildings.*8 This page covers closed-loop chilled-water and heating hot-water piping. It is not for steam lines. In multifamily buildings, it fits those with a central plant circulating hot or chilled water.
Does it work on hot heating loops, or loops with inhibitors or glycol?
Yes. On loops above 70°C (158°F), insulation is wrapped around the pipe where the unit is mounted. Corrosion inhibitors and glycol in the water are no problem.*1
Main size, model and list price
| Main size | Model | List price |
|---|---|---|
| 3″ | PT-75DS | $31,642 |
| 4″ | PT-100DS | $46,305 |
| 5″ | PT-125DS | $57,881 |
| 6″ | PT-150DS | $84,562 |
| 8″ | PT-200DS | $116,755 |
| 10″ | PT-250DS | $141,341 |
| Main size | Model | List price |
|---|---|---|
| 12″ | PT-300DS | $165,706 |
| 14″ | PT-350DS | $189,520 |
| 16″ | PT-400DS | $213,554 |
| 18″ | PT-450DS | $237,699 |
| 20″ | PT-500DS | $261,734 |
List price per unit, before shipping, import duty and tax.*16 We confirm the model and the number of units from your photos or drawings. In the trial, you buy only if iron halves, at the price agreed up front.
Installing, and who does it
About an hour per unit, with the system running.*3 Pick the model for your pipe size, clamp the upper and lower housings around the pipe, and bolt them together.
01 — Size it to the pipe 
02 — Clamp top and bottom 
03 — Bolt it tight
Who installs it in the US?
Your building engineers, the people who maintain your piping, or a licensed local mechanical contractor install it, with an engineer from Japan supervising on site. The licenses required vary by state and building, so we confirm them in advance. In Hawaii and Washington, DC, engineers from Japan did the installation.*8
Do you have to cut the pipe to install it?
No. The upper and lower housings clamp around the outside of the pipe and bolt together. Each unit takes about an hour.*3 If the insulation at the mounting point has to be opened, older buildings need an asbestos survey first, and a licensed contractor removes and restores the insulation. Sometimes the unit can go on a bare section of pipe.
Compared with the usual options
The usual options replace the pipe or fight the rust. NMR Pipetector turns the rust itself into a layer that protects the pipe.
| Item | Repiping | Epoxy pipe lining | Chemical water treatment | NMR Pipetector |
|---|---|---|---|---|
| Method | Open walls and ceilings and replace the pipe | Drain and dry the pipe, then coat the inside with resin | Keep dosing chemicals and managing water quality | Mounts on the outside of the pipe; the device itself uses no power and no chemicals |
| System | Down during the work | Shut down while the lining is applied | Stays in service | Installs without a shutdown |
| The rust | Replaced along with the old pipe | Covered by the coating | Slowed down | Turns into black rust, a protective layer*4 |
| Cost | High | High | Ongoing chemical refills and water testing | Device price, quoted in writing first; buy only if iron halves; your water treatment continues |
Lost wall thickness doesn't come back, and spots that are already leaking need separate repair.
How it works
Why turn red rust into black rust?
Red rust eats the pipe. Black rust protects it.
| Property | Red rust | Black rust |
|---|---|---|
| Structure | Porous and flaky. It crumbles off | Dense and hard |
| Behavior | Keeps growing, eating the pipe from the inside | Stops growing and bonds tightly to the wall |
| In water | Dissolves, turning the water red | Does not dissolve |
| For your pipe | Causes pinholes and clogs | Armor that protects the steel |
You already know black rust. It's the blue-black finish on a heat-blued carbon-steel wok and the black-oxide coating on drill bits. NMR Pipetector builds that same protective film on the inside of your pipes.*4
How does red rust turn into black rust?
From red rust to black rust
Step 1 of 4
Red rust builds up
Iron and the oxygen in the water form red rust, which builds into lumps (tubercles) that narrow the pipe.
- 01 Red rust builds upIron and the oxygen in the water form red rust, which builds into lumps (tubercles) that narrow the pipe.
- 02 Water clusters break apartThe device's electromagnetic waves break large clusters of water molecules into smaller ones.
- 03 Hidden electrons come outElectrons hidden inside the clusters are released by the flowing water and reach the red rust.
- 04 A black-rust film formsRed rust that receives electrons becomes a dense, hard film of black rust.*4
For engineers
Ceramics inside NMR Pipetector emit a specific electromagnetic wave that causes nuclear magnetic resonance (NMR) in the hydrogen nuclei of the water. Water molecules form large hydrogen-bonded clusters. The resonance breaks them into smaller clusters, bringing electrons from the inside to the surface. This state lasts more than 6 hours.
Red rust forms: 4Fe + 3O₂ + 2H₂O → 4FeO(OH)
Red rust becomes black rust: 6FeO(OH) + 2e⁻ → 2Fe₃O₄ + 2H₂O + 2OH⁻
Red rust, FeO(OH), is a brittle, layered crystal that dissolves into the water. Black rust, magnetite (Fe₃O₄), is a dense spinel-type crystal. It takes up roughly one-tenth the volume, bonds tightly to the pipe wall, and does not dissolve in water.*4
How the trial is judged
- We compare iron in water sampled at the same point before and after installation.
- Water samples used to judge the trial are collected in our presence and analyzed by the lab your facility already uses.
- The lab sends its results directly to your building and to us.
- If your building already tests its water regularly, the pre-installation level is the average of the three most recent lab reports for the same loop and sampling point, issued before the trial agreement; if not, it is one sample taken before installation in the same way.
- After installation, the average of the three most recent results is compared with the pre-installation level, and the trial is a success when it is half or lower.
- The result is judged within 3 months, or earlier if the target is met sooner.*7
- On a seasonal changeover loop (hot water in winter, chilled water in summer), the pre-installation level and the judging samples are both taken in heating mode, and the unit is installed in time for judging to finish before the switch to cooling: for the full 3 months, by late January at the latest, depending on your building's switchover date.
- The success criterion and the purchase price are set in a signed trial agreement before the trial: if the agreed target is met, you buy the trial unit; if not, you don't buy it.
Round 1 starts with heating hot-water loops, including seasonal changeover loops while they run hot water. The trial uses one loop; other loops follow once the effect is confirmed.
An engineer from Japan supervises every Round 1 installation on site. We check the result as soon as iron falls by half. That can be within weeks; 3 months at most.
Closes November 30, 2026 (November 30, 2026, 11:59 p.m. ET)
Round 1 is now closed. We will announce the next round soon.
Photo guide to share (PDF) (opens in a new tab). Send this guide to the person taking the photos.
All questions
What pipe types and sizes does it work on?
It mounts on iron and steel pipe, including black steel and galvanized steel pipe, and on copper pipe. Models range from about 1 to 80 inches (25 mm to 2,000 mm); for the Round 1 trial we focus on the 3- to 20-inch mains common in commercial buildings.*8 This page covers closed-loop chilled-water and heating hot-water piping. It is not for steam lines. In multifamily buildings, it fits those with a central plant circulating hot or chilled water.
Does it work on hot heating loops, or loops with inhibitors or glycol?
Yes. On loops above 70°C (158°F), insulation is wrapped around the pipe where the unit is mounted. Corrosion inhibitors and glycol in the water are no problem.*1
How many units do we need?
One for each circulating loop (each chilled-water or heating hot-water system), mounted on that loop's main pipe. One unit covers about 2 km (about 6,500 ft) of piping in that loop. So the number of units depends on how many loops you have, and the model on the size of the main. If a loop has more piping than that, we may ask for drawings to confirm the count. A loop where water flows faster than 2 m/s (about 6.56 ft/s) takes two units, installed in series. The mounting point needs at least 130 mm (about 5 inches) of straight pipe.*1 We confirm the number of units and the model from your photos.
Round 1 starts with heating hot-water loops, including seasonal changeover loops while they run hot water. The trial uses one loop; other loops follow once the effect is confirmed.
How much does it cost?
Each unit is priced by the size of the main: from $31,642 for a 3-inch main to $261,734 for a 20-inch main, with every size in the model table on this page. A loop takes one unit, or two in series if water flows faster than 2 m/s (about 6.56 ft/s). List prices are for the unit itself, before shipping from Japan, import duty and U.S. sales or use tax.*16 An inquiry commits you to nothing: after a quick photo pre-check, if NMR Pipetector fits, you receive a written price for your building and a draft trial agreement for your owner or board, and nothing is signed until they approve. Try it on one loop. Within 3 months, iron drops to half the starting level or less? You buy the trial unit at the price agreed up front. If not, you don't buy it.*7
Who installs it in the US?
Your building engineers, the people who maintain your piping, or a licensed local mechanical contractor install it, with an engineer from Japan supervising on site. The licenses required vary by state and building, so we confirm them in advance. In Hawaii and Washington, DC, engineers from Japan did the installation.*8
Do you have to cut the pipe to install it?
No. The upper and lower housings clamp around the outside of the pipe and bolt together. Each unit takes about an hour.*3 If the insulation at the mounting point has to be opened, older buildings need an asbestos survey first, and a licensed contractor removes and restores the insulation. Sometimes the unit can go on a bare section of pipe.
Can it restore pipe that has already thinned?
No. Lost wall thickness doesn't come back, and any spots that are already leaking need separate repair. From here on, it turns the red rust that forms into black rust, which doesn't dissolve into the water.*4
How do we know it's working?
We compare iron in water sampled at the same point before and after installation. Trial samples, collected in our presence, are tested by your usual lab, which sends its results directly to your building and to us. The trial is a success when iron is half the pre-installation level or lower, within 3 months.*7 The full rules, including how the pre-installation level is set, are under How the trial is judged.
Is black water in a chilled-water loop a bad sign?
Black water often contains fine particles of black rust (magnetite). Black rust is more stable than red rust, so black water is not necessarily an immediate danger. As the particles build up, though, they can clog strainers and heat exchangers and reduce flow. If reddish-brown water appears or iron keeps rising, corrosion may be progressing, and we recommend checking it with a water test. Read the full guide
How much iron is too much in a closed loop?
There is no single standard, and guidelines vary by source. For example, one water treatment company's guideline is below 1 ppm (mg/L), and one university's facility specification sets a limit of less than 2 ppm. What matters most is whether iron is higher than in the makeup water, and whether it keeps rising. This trial judges the result against your building's records or the pre-installation level.
Does it work in systems that mix copper or stainless steel?
Yes. Copper and stainless steel resist rust themselves, but the steel fittings and valves connected to them can still rust, and that rust can start corrosion where it settles on other metals. NMR Pipetector works on the water in the loop and turns the red rust in it into black rust.*1
Does it work in a closed loop with little makeup water?
It works as long as some water flows through the pipe where it is mounted every day. In a closed loop, water circulates whenever the pump runs, so a loop with little makeup water can still be part of the trial. The guideline is at least 8 hours a day and 6 months a year of operation.*1 Loops that stay off for long periods, such as heating in summer, are tested while they are running.
Is this a magnetic water conditioner?
No. NMR Pipetector works with electromagnetic waves: ceramics inside the unit emit them, and a component made of magnets concentrates them and sends them into the pipe. It does not treat water with magnetism.*4 The case-study results were measured as iron in the water before and after installation, and your trial is judged the same way.
Has it been independently verified?
Your trial is decided by your own building's numbers: we compare the average of your usual lab's three most recent results after installation with the pre-installation level. If iron doesn't fall to half or lower, you don't buy the unit. The figures in the case studies were measured at the installation sites; in the UK and elsewhere, analytical laboratories ran the tests. No trial has yet compared a loop with the unit side by side against one without it.
Can iron levels fall for reasons other than the unit?
Yes. Flushing, filtration, changes to water treatment and seasonal changes in operation can all change iron levels. That's why we ask you to keep your current water treatment unchanged during the trial, and we judge the result on the average of the three most recent results, not on a single sample. If you flush, repair or do other work that could affect iron levels, please let us know.
Does it need power or maintenance?
Neither.*1 It works as long as some water flows through the pipe every day.
Can we keep our current water treatment?
Yes. Keep your treatment program unchanged during the trial so the before-and-after numbers compare fairly. We share the results with your water treatment provider.
Do we need to flush or drain the system before the trial?
No flushing or draining is needed for the trial. During the trial, please keep your current water treatment unchanged, so that the before-and-after comparison is made under the same conditions. If the system needs flushing or repairs, those come first; please let us know.
About us
Bringing it to US buildings
Everyone assumes an aging building's pipes will eventually have to be replaced. Yet in Japan, a device that takes on rust from outside the pipe has been in use for more than 30 years. When we found it, we were amazed. Tengcle Development LLC brings NMR Pipetector to buildings across the United States. We learn how your building and piping work, confirm the fit before anything is signed, and stay with you, alongside the engineers from Japan, all the way through the trial installation.
Tengcle Development LLC is your US point of contact from the photo pre-check to the final result, for scheduling and all follow-up. Japan System Planning Co., Ltd. holds the contract and the product warranty.