Pipe-type transmission · 69 kV to 345 kV
HPFF pipe-type cable buyers in New York
High-pressure fluid-filled cable carried bulk power under New York City long before extruded cable could do the job. When a feeder is retired, what comes back out of the ground is a coated steel pipe, a quantity of dielectric oil and three very large copper conductors.
- New York State
- Documented lots
- Reels and cut lengths
- Buyer review
Sell this cable
Send the construction, size and footage. Photographs can follow.
Prefer to talk? 614-715-3047 · saleselectricalbuyers@gmail.com
HPFF is three assets in one trench: the copper conductors, the steel pipe and the dielectric fluid. Copper usually decides the number; the pipe and the oil decide whether the removal is straightforward or expensive. Footage, conductor size, pipe bore, splice count and the state of the oil are the five facts a buyer needs before anything can be quoted.
Why the cable lives inside a steel pipe
Paper is an excellent dielectric only while it is dry and free of voids. At transmission stress a void ionises, the discharge erodes the paper, and the cable fails from the inside out. The HPFF answer is to impregnate the paper with degassed oil and hold the whole run under positive pressure inside a welded steel pipe, so any void that tries to form is collapsed by the fluid rather than left to discharge.
Each of the three cables is a large copper conductor wrapped in many layers of oil-impregnated paper, screened, sheathed in lead alloy, taped, and fitted with copper skid wires that let it be pulled through the pipe without stripping the sheath. The pipe is coated, usually with a coal-tar enamel or taped system, and cathodically protected against the soil it spends its life in.
That construction explains what an HPFF route looks like from the street. It looks like plumbing: valve and test points, cathodic protection stations, oil lines running alongside the pipe, and at the substation ends, oil-filled potheads on structures next to a pressurising plant with tanks, pumps and pressure alarms. Loss of pressure is loss of dielectric, so the plant is monitored continuously, and every fitting on it is part of the same asset as the cable.
It also explains why this construction is expensive to install and therefore rare outside dense cities. Joint bays have to be excavated, splices are hand-taped paper joints enclosed in welded steel casings, and the pipe has to be welded, coated, tested and evacuated before oil goes in. New York City is one of the few American markets where the economics have always worked.
Three value streams, priced separately
Sellers describe pipe-type cable as one thing. A buyer cannot. The copper is a metal asset priced on size, recovery condition and whether the conductor comes out clean. The pipe is a steel asset priced on bore, wall thickness, coating condition and the length of the sections it can be cut into. The oil is a fluid with a disposal cost and, depending on its chemistry and history, sometimes a recovery credit.
Copper dominates. HPFF conductors are large — segmental copper in the 1,000 to 2,500 kcmil range is normal at 345 kV, built as four or six segments around a central oil duct so that fluid can reach the middle of the conductor as well as the insulation. Copper at 1,000 kcmil runs a little over three pounds per conductor foot, so a three-conductor pipe feeder is a copper quantity that has to be scheduled rather than guessed.
The lead sheath is a fourth and smaller stream, and it is a handling obligation before it is a value line. Lead alloy is recoverable, but it is a controlled material: the crew stripping it needs the hygiene controls, PPE and medical surveillance that go with lead, and the buyer needs to know it has been separated from the paper rather than burned off.
The trap in these lots is a single scrap price applied to the whole assembly. A pipe feeder contains steel, copper, lead, brass, oil and paper in one package, and a yard that quotes per ton on the lot is pricing the copper at steel value and charging for the oil.
| Stream | What it is | What decides its value |
|---|---|---|
| Copper conductor | Segmental or stranded copper with paper wrap and oil ducts | Size in kcmil, clean recovery, whether lengths are straight and coiled |
| Steel pipe | Coated welded steel with cathodic protection, cut into liftable joints | Bore, wall thickness, coating and corrosion, section length |
| Dielectric oil | Pressurised insulating fluid drained from the pipe | Volume, chemistry, PCB screening, permitted disposal route |
| Lead sheath | Alloy sheath stripped from each conductor | Weight, and how cleanly it separates from paper and copper |
What a decommissioned section actually yields
A retired feeder is not a drum of cable. It is a pipe run in welded joints, with splice casings at intervals, bends, and potheads at both ends. To get the copper out, the pipe is cut and opened, then the cable is pulled or stripped. Some conductor comes out long enough to be coiled and reused; most does not, because pulling damages the sheath and the paper, and the lengths between splices are short.
What the job produces is therefore a set of streams rather than a product: copper conductor in cut lengths and loose segments, lead sheath, coated steel pipe in short sections, splice casings and potheads with recoverable brass and copper content, and oil that has to be drained and documented. Value comes from matching each stream to the buyer who wants it, instead of sending the lot to one yard as heavy scrap.
Terminations and splices deserve a look before anything is cut. A pothead that came off intact carries a substantial brass or copper fitting and a porcelain or epoxy housing. A splice casing is a fabricated steel shell with copper connectors inside, and the paper joint in the middle holds a good deal of copper that never sees a cable reel.
- Conductor size and footage are the first two questions, and both are usually on the utility's cable records even when the drum tag is long gone
- Splice count sets the recovery method: every casing is a cut, and every cut shortens the reusable lengths
- Pipe bore and wall thickness decide whether the pipe is worth trucking or is a disposal cost
- Potheads and pressurising equipment are priced as fittings, not as pipe
- Oil volume and test history decide the disposal route and therefore the net position on the job
The handling constraints are the job
Oil comes first. A six-inch pipe holds on the order of a gallon and a half of dielectric fluid per foot before the cables take up space, so a mile of feeder is thousands of gallons. It has to be drained at low points into containment, sampled, and sent for reclamation or disposal by a permitted handler. Fluid from cable installed before the late 1970s may need PCB screening before anyone can decide where it can go.
Pipe comes second. Cutting a coated steel pipe that has held oil for decades is cold work: abrasive saw, hydraulic shear, or a controlled cut with the section purged. Hot work next to residual oil is how these jobs go wrong. Any vault, manhole or chamber entry is a confined-space entry with the permits, gas monitoring and rescue arrangements that go with it, and the cable must be de-energised, isolated and released by the owner before a single clamp is loosened.
Weight and access come third. Six-inch schedule 40 pipe weighs about nineteen pounds per foot empty and considerably more with three large conductors inside it. Sections have to be lifted out of a street cut, which means crane position, lane closures, and in the city, permits that fix the hours you are allowed to work. Cable that cannot be coiled on a reel on site is cut into lengths two people can carry up a stair.
Specification
What a buyer needs to know about this cable
Every row below changes what a lot is worth. If the reel tag is gone, the jacket print and a cut end usually answer most of it.
Missing detail is not a problem — say what is missing and the review works from photographs.
| Construction | Three single-core paper-insulated, lead-sheathed conductors pulled into one welded steel pipe |
|---|---|
| Insulation | Oil-impregnated paper tape applied in many layers over a screened conductor |
| Conductor | Segmental or stranded copper with integral oil ducts; commonly 1,000 to 2,500 kcmil at 345 kV |
| Pipe | Coated welded steel, typically 5 in to 8 in bore, with cathodic protection and test stations |
| Fluid | Degassed dielectric oil held under pressure, commonly in the region of 200 psi on transmission feeders |
| Voltage classes | 69 kV, 138 kV and 345 kV underground transmission |
| Ends | Oil-filled potheads, welded splice casings and a pressurising plant |
| Handling | Oil drain-down and containment, cold pipe cutting, lead sheath controls, per-foot weight |
Constructions
HPFF material that comes off a New York job
The same pipe feeder produces very different material at each end of the run and at every splice in between.
345 kV transmission feeders
The largest conductors in the state's underground network, in the widest pipe, with potheads and a pressurising plant at both ends. Copper quantity is the whole conversation.
138 kV and 69 kV pipe feeders
Smaller conductors and shorter runs between substations, usually with more splices per mile, which means more casings and shorter reusable lengths.
Splice casings
Welded steel shells over hand-taped paper joints, with copper connectors and a wrapped joint inside. Priced as a fitting, then stripped.
Potheads and sealing ends
Oil-filled terminations that carry brass, copper and a housing that may be reusable if it came down without cracking.
Removed pipe sections
Coated steel in liftable joints. Bore, wall and coating decide whether it is worth a truck or is a disposal line on the job sheet.
Pressurising plant and oil
Tanks, pumps, gauges and oil lines, plus the fluid itself — a documented disposal or reclamation stream, not a liquid to be drained to grade.
New York
Pipe-type cable in the New York market
New York City's bulk transmission is largely an underground pipe-type network. The 345 kV feeders that tie the city into the state grid run as HPFF in steel pipe beneath streets and through utility vaults, with 138 kV and 69 kV pipe feeders beneath them in the same rights of way. Few American markets hold this concentration of paper-and-pipe cable, and few produce it as surplus.
Removal is owner-driven. A feeder is retired when extruded cable replaces it, when a substation is rebuilt around a different configuration, or when street reconstruction takes the route apart. The cable leaves through the utility's material management or its contractor's, and the records — oil manifests, footage, splice locations — usually exist. Getting those records into the enquiry is what separates a priced lot from a speculative one.
What helps a New York lot move
- Cable records or as-built drawings showing footage, conductor size and splice locations
- Pipe bore and wall thickness, and whether the coating is intact
- Whether the oil has been drained, and the sample or manifest that proves it
- How the pipe is being cut and where the sections can be set down
- Street access: permit hours, crane position, and whether a vault entry is needed
Seller questions
Questions sellers ask
Can removed HPFF cable be reused as cable?
Almost never as a pressurised feeder. Pulling the cable out of the pipe damages the lead sheath and the paper, and a paper insulation system that has lost its oil and its pressure cannot be restored outside a factory. The value is in the copper, the lead, the pipe and the fittings, with reuse limited to a section that was cut out intact and kept under oil.
How much oil is in a pipe-type feeder?
A six-inch pipe holds roughly a gallon and a half of dielectric fluid per foot before the cables displace it, so a mile of feeder runs into thousands of gallons. The exact volume depends on bore, wall thickness and conductor size. The fluid has to be drained into containment, sampled, and sent to a permitted handler.
Do you want the pipe as well as the copper?
Yes, and it is priced on its own terms. Bore, wall thickness, coating condition and the length of the sections decide what the steel is worth; a corroded pipe that has to be cut into short pieces is closer to a disposal cost. Coating damage matters because it is what protected the pipe for its service life.
What if the oil has not been drained yet?
Then the enquiry is a removal project rather than a material sale, and it is priced with that in mind. Nobody lifts a pipe full of fluid. The usual sequence is that the owner's contractor drains, caps and purges the section, and the material is reviewed once the pipe is empty and the fluid documentation exists.
How is a section with a splice in it valued?
By the copper on each side of the casing, the casing itself, and whether the joint can be opened without destroying the conductor. A splice shortens the reusable lengths either side of it, but it also adds a fabricated steel shell and copper connectors, so it is counted rather than ignored.
Keep reading
Related pages
- PILC cable buyersThe paper/lead construction without the pipe
- 345 kV cable buyersThe voltage class that made pipe cable necessary
- 230 kV cable buyersThe tier below
- High-voltage cable buyersThe wider transmission category
- Splice kit and accessory buyersCasings, joints and terminations
- Medium-voltage cable buyersWhere the distribution network starts
Next step
Send the lot details
Include the storage city, how it is stored and what can reach it. If you have photographs of reel tags or jacket print, send them with the enquiry.
Send the lot
One desk reviews every lot that arrives.
Prefer to talk? 614-715-3047 · saleselectricalbuyers@gmail.com