NMX‑HPJ‑30 / Rev 00 / jetting & desilting / pressure · flow · recovery 2026 · Product Page

NMX-HPJ-30 · ENGINEERED TO ORDER — HIGH-PRESSURE WATER JETTING & DESILTING MACHINES

Pressure cuts it loose. Flow is what carries it away.

Name: High-Pressure Water Jetting & Desilting Machines
Brand: Neometrix

They are two different tools, and a machine has to be bought on both. Take pressure without flow and the jet cuts a neat hole straight through the blockage, leaving the rest exactly where it was. Take flow without pressure and loose material moves happily while anything genuinely bonded is untouched. What you are removing sets the ratio, and the ratio sets the pump, the nozzle and the machine. Two things follow that most buyers meet too late. The reaction force on a lance is a safety limit, not an ergonomic one — past what a person can brace against, a hand lance is simply not controllable, and a jet injures by injection through skin rather than impact. And the hard part is not the jetting at all: it is what comes back — recovering water and solids, and, on a vehicle, the payload arithmetic that decides the chassis. Equipment of this class has been quoted across high-pressure water jetting and desilting requirements for naval, municipal and industrial users; no delivered high-pressure water jetting or desilting machine is claimed — the class is engineered to order.

Enquire — jetting & desilting Capability sheet (PDF)

Illustrative of the class — a vehicle-mounted combination water jetting and desilting unit parked on clean concrete in an open yard: a plain unbadged white truck chassis cab carrying a large horizontal cylindrical light-grey painted steel sludge tank with a domed rear door and stainless catches, a black rubber suction boom folded along the top of the tank, a yellow and grey high-pressure hose reel wound with black hose at the rear, a light-grey control cabinet with completely blank faces, galvanised handrails and rear step, no people, no water running and no readable markings or number plate

Fig · 01 The combination unit — and the tank behind the cab is what decides how long it can keep working

Sized on

pressure × flownot either alone

Limit

reaction forcehand or machine

Judged on

what comes backrecovery & separation

Built as

vehicle or skidto the site

Status

engineered to orderquoted class

ISO 9001 / 14001 Engineered to order Jetting & desilting Vehicle & skid builds Noida · India

Overview

Anyone can make water come out fast.

The difficulty is choosing how fast against how much, keeping the lance controllable while you do it, and having somewhere to put what you just washed off.

Illustrative of the class — a high-pressure water jetting pump package on a workshop floor: a compact horizontal triplex plunger pump in machined aluminium and steel with three visible plunger housings, belt-driven from a large blue-grey electric motor through a guarded belt drive with a light-grey mesh guard, mounted on a light-grey painted steel skid base with levelling feet, thick stainless high-pressure discharge pipework with cone-and-thread fittings, a stainless inlet filter bowl, and a plain unmarked light-grey control cabinet behind, no people, nothing running and no readable markings

Fig · 02 The pump — and the small stainless bowl on the left is what keeps it alive

Pressure and flow do different jobs, and the machine needs both. Pressure is what breaks the bond — it is the part that gets scale off a tube wall, hardened deposit off a floor, or a compacted plug moving at all. Flow is what then transports the loosened material out of the way. The hydraulic power available is the product of the two, so for a given pump there is a genuine trade: push the pressure up and the flow comes down. Get the ratio wrong in one direction and you bore a clean hole through a blockage while everything around it stays put. Get it wrong in the other and you flush the loose material away and leave the hard deposit polished and intact. Neither is a pump fault. Both are specification faults.

The lance pushes back, and that decides the architecture. A jet leaving a nozzle carries momentum, so it exerts a reaction on whatever is holding it, proportional to flow and jet velocity. There is a point past which no operator can brace against that force for a working shift — and a lance that gets away from someone is not an inconvenience, it is a fatality risk. So this force is worked out before anything else. Beneath the limit, a hand lance is legitimate, fitted with a dead-man control that shuts the jet the instant it is released and an anti-withdrawal device so a flexible lance cannot be pulled back out of a pipe and turned on the operator. Above the limit, the lance is machine-mounted or remotely operated, and that is not a luxury specification — it is the only honest answer.

And then there is everything you just washed off. This is the half that separates a machine that works from a machine that works for ten minutes. Recovered material has to be sucked up, separated from the water, held somewhere and eventually tipped out. On a vehicle that means arithmetic rather than opinion: sludge is heavy, the tank position and volume govern axle loading and legal payload, and the payload decides which chassis the machine can be built on at all.

Equipment of this class has been quoted across high-pressure water jetting and desilting requirements for naval, municipal and industrial users. No delivered high-pressure water jetting or desilting machine is claimed: the class is engineered to order, and the record is stated as it stands.

Matched

Pressure against flow

Sized on the product of the two — and on what is actually being removed.

Controllable

Reaction force first

Dead-man and anti-withdrawal below the limit — machine-mounted above it.

Self-sufficient

Somewhere to put it

Recovery, separation and payload — the half that decides usefulness.

Architecture

Cut it loose, carry it away, then put it somewhere.

The schematic follows the material rather than the water — broken loose, transported, recovered, taken off site — then the four blocks that do it: pump and drive, delivery, recovery and separation, and the carrier with its controls and safety.

FIG · 03JETTING & DESILTING ARCHITECTURE · PUMP + DRIVE / LANCE + REEL + NOZZLES / RECOVERY + SEPARATION / CARRIER, CONTROL + SAFETY

Fig · 03 The reaction force decides the architecture before any of the rest is chosen

Arc · 01

High-Pressure Pump & Drive

Plunger pump, engine or motor drive — unloader and relief, pulsation control, and regulation of both pressure and flow.

Arc · 02

Lance, Hose Reel & Nozzles

Nozzle selection is tool selection — and the reel decides reach, and how fast the machine can actually be worked.

Arc · 03

Recovery & Separation

Vacuum, solids separation, sludge tank — decanting the water back off so the tank holds material rather than liquid.

Arc · 04

Carrier, Control & Safety

Chassis or skid, dead-man, interlocks — guarding, and the payload arithmetic that decides what can be built at all.

Not sure whether the job needs pressure or flow? Send what is being removed and what it is stuck to, the access, the water available and where the spoil goes — a clause-by-clause compliance matrix within two working days · [email protected]

Send tender spec

Specifications

Reference builds, sized to the deposit.

The parameters below describe reference machines. Pump rating, nozzle set, reel capacity, recovery volume, tank size and carrier all follow from four givens: what is being removed and what it is bonded to, the access, the water available, and where the spoil is going.

Illustrative of the class — the delivery end of a water jetting machine in a clean workshop: a large light-grey painted steel hose reel neatly wound with black high-pressure hose with a chromed swivel and guide roller in the foreground, a straight polished chrome hand lance with a plain black moulded grip and a machined stainless nozzle head resting on a light-grey painted steel bench, and a set of small machined stainless nozzle tips of different sizes laid out in a plain grey foam tray, plain unmarked light-grey panelling behind, no people, nothing running and no readable markings

Fig · 04 Nozzles — the tips in the tray are the actual cutting tools, and choosing them is the job

Where these machines go wrong

Bought on pressure alone — the specification names a headline pressure, the job actually needed flow, and the machine bores through blockages instead of clearing them. Reaction force never calculated — a hand-held lance is supplied at a duty no operator can hold, and the crew quietly work at reduced pressure ever after, which means the machine was never the size it was bought as. No inlet filtration — site water carries grit, and grit is what destroys plunger pumps, so the most expensive component in the machine is ruined by the cheapest one that was left out. Recovery undersized — the tank fills, the job stops, and the round trip to tip out costs more time than the jetting saved. Payload ignored — the machine is legal empty and overloaded full, which is discovered at a weighbridge. And nozzles treated as an accessory — when the nozzle is the tool, and the wrong tip makes a correctly specified pump useless.

So the discipline runs the other way. The duty is established first — what is being removed, and what it is bonded to — and the pressure-to-flow ratio follows from that rather than from a catalogue. Reaction force is calculated before the architecture is chosen, and it decides hand-held against machine-mounted rather than the other way round. Inlet filtration is specified as part of the pump, not as an option. Recovery volume is matched to the jetting rate and the realistic distance to the tipping point, so the machine works a shift rather than a burst. The payload sum is done full, not empty. And the nozzle set is chosen and documented as the tool kit it is, with the operator trained on which tip does what.

Full specification — expand

System	High-pressure water jetting & desilting machine — pump & drive, lance, hose reel & nozzles, recovery & separation, carrier, control & safety
Governing Idea	Pressure and flow are two different tools — pressure breaks the bond, flow carries it away, and the machine is sized on the product of the two
The Classic Error	Buying pressure when the job needed flow — a neat hole through the blockage, and the rest of it exactly where it was
Reaction Force	Set by flow and jet velocity, and calculated before the architecture is chosen. Below the limit: hand lance with dead-man control and anti-withdrawal device. Above it: machine-mounted, remotely operated, or rigid lance and hose feed
Why It Is A Safety Limit	A high-pressure jet injures by injection through skin rather than by impact — a wound that looks trivial from outside can be a surgical emergency, so control of the lance is not an ergonomic question
Recovery	Vacuum or suction, solids separation, sludge tank and decanting — the half that decides whether the machine is still working ten minutes in
Vehicle Arithmetic	Recovered material is heavy. The tank governs axle loading and legal payload, and the payload decides the chassis — the sum is done full, not empty
Water	A consumable and a constraint: supply and carried volume, inlet filtration because grit destroys a plunger pump and site water is rarely clean, recycling where recovery allows it, freeze protection where the machine works cold
Nozzles	Nozzle selection is tool selection. The set is chosen for the deposit, documented, and the operator is trained on which tip does what
Variants	Vehicle-mounted combination jetting & desilting unit · skid or trailer high-pressure cleaning machine · shipboard high-pressure cleaning set · fixed high-pressure rinsing installation
The Split	The site's chemical cleaning bay works by chemistry — it dissolves the bond by immersion and leaves effluent to treat; this works by energy, with no chemistry at all. Shot blasting and peening is dry abrasive — media to recover and dust to contain; here there is no dust, but water and solids to recover. And the engine compressor washing rig is subject-specific and deliberately gentle, cleaning one component without damaging it — this is the general-purpose high-pressure machine
Scope Boundary	Ours: machine design & integration, pump & drive package, lance, hose reel & nozzle selection, recovery & separation, sludge handling, carrier or skid integration and the payload arithmetic, controls, dead-man & interlocks, guarding, site survey, installation, commissioning, documentation, training, spares & AMC — including build to the customer's specification. Bought-in certified: the high-pressure plunger pump, the prime mover, the vacuum package, the chassis. The customer's: the site, the water supply, the material to be removed and its disposal route
Status	Engineered to order — equipment of this class quoted across high-pressure water jetting and desilting requirements for naval, municipal and industrial users; no delivered high-pressure water jetting or desilting machine is claimed

PDF · 1 page

High-Pressure Water Jetting & Desilting — Capability Sheet

Tender Response

Send the deposit, the access & where the spoil goes — compliance matrix in two working days

Variants

Same physics, four machines.

What changes is how far the machine has to travel, how much it has to carry, and whether it recovers what it removes.

Var · 01

Vehicle-Mounted Combination Unit

Jetting and recovery on one chassis — self-sufficient on site, and governed throughout by the payload sum.

Var · 02

Skid or Trailer Cleaning Machine

Taken to the work rather than driven — craned or towed into place where a vehicle cannot reach.

Var · 03

Shipboard Cleaning Set

Compact, marinised and stowable — sized for what a deck or compartment will actually take.

Var · 04

Fixed Rinsing Installation

Plumbed in where the work comes to it — a bay or line station with permanent supply and drainage.

Applications

Wherever something will not simply wash off.

The duties where scrubbing has stopped working and chemistry is the wrong answer.

A · 01Naval & shipyard cleaning

A · 02Sewer, manhole & culvert desilting

A · 03Industrial plant & tank cleaning

A · 04Heat exchanger & pipe cleaning

A · 05Surface preparation & coating removal

A · 06Drain maintenance for public works

FAQ

Common questions.

Plain-language answers from the engineering team.

Q · 01 How do I know whether my job needs pressure or flow?

Ask what is holding the material in place. If it is bonded — scale grown onto a tube wall, hardened deposit, cured product, coating — then something has to break that bond, and breaking bonds is what pressure does. If it is merely sitting there — silt in a culvert, sand in a sump, sludge in a tank bottom — then the bond is weak or absent and the whole problem is transport, which is what flow does. Most real jobs are a mixture, which is why the ratio matters rather than either number alone. A useful way to think about it: the pump gives you a fixed amount of hydraulic power, and you are choosing how to spend it. Spend it on pressure and you get a concentrated, aggressive jet that removes a small area very effectively — excellent on hard deposit, useless for moving volume. Spend it on flow and you get a large, energetic wash that shifts a lot of material — excellent in a drain, hopeless on scale. The practical consequence for a buyer is that a specification quoting only a headline pressure has not actually described the duty, and two machines with the same pressure rating can behave completely differently. Describe the deposit and what it is stuck to, and the ratio follows from that.

Q · 02 What is the reaction force, and why does it decide the design?

Water leaving a nozzle carries momentum, and by Newton's third law the lance is pushed back with an equal and opposite force. That force rises with both the flow and the jet velocity, which means it rises as you make the machine more capable — the better the machine, the harder it is to hold. There is a threshold beyond which a person cannot brace against it safely for a working shift; the exact figure depends on posture, footing and how long the operator has to hold it, but the important thing is that it is a real, calculable limit rather than a matter of toughness. Above that threshold the honest answer is that the lance must not be hand-held at all: it is mounted on the machine, fed mechanically into the pipe, or operated remotely. Below it, a hand lance is legitimate but never bare. It carries a dead-man control, which shuts the jet the moment the operator lets go or falls, and for flexible lances used inside pipes an anti-withdrawal device, which prevents the lance being pulled back out of the pipe while jetting — because a flexible lance that comes out of a pipe under pressure whips, and it is pointing at the operator. None of that is comfort specification. It is the difference between a machine that is safe and a machine that is merely powerful.

Q · 03 Why is a high-pressure jet injury treated so seriously?

Because it does not injure the way people expect. The instinct is to think of a jet as something that hits you, like being struck, and to judge the seriousness by how the skin looks afterwards. A high-pressure water jet does something quite different: it injects. The stream penetrates the skin through a small entry point and drives water — along with whatever the jet had just been cleaning, which is rarely sterile — deep into the tissue along the paths of least resistance, between muscle planes and along tendon sheaths. From outside, the entry wound can look like a pinprick and can be almost painless at first. Underneath, there can be extensive contamination and tissue damage, and swelling in a confined compartment can cut off the blood supply. This is why the medical guidance for these injuries is unambiguous and urgent: they are surgical emergencies, they need to be treated by someone who understands injection injury specifically, and the trivial appearance of the wound must be disregarded. For a designer, the consequence is straightforward. You cannot rely on an operator's judgement of risk, because the risk does not look like what it is. So control of the jet has to be built in — dead-man, anti-withdrawal, mounting above the force limit — and the operator training has to say this explicitly rather than leave it to be discovered.

Q · 04 Why does inlet filtration matter so much?

Because a high-pressure plunger pump is a precision machine being asked to work with whatever water the site has, and those two facts are in direct conflict. The pump seals against its plungers with very tight clearances at very high pressure. Introduce hard particles — sand, grit, rust, scale from the supply line, silt from a recycled tank — and they act as a lapping compound, scoring the plungers and destroying the seals. The failure is not dramatic, which is part of the problem: performance falls off gradually, the machine is judged to be tired, and seals get replaced repeatedly without anyone identifying the cause. The remedy is unglamorous and cheap relative to the pump: adequate inlet filtration sized for the actual flow, positioned so it can be inspected and cleaned easily, with enough capacity that it does not starve the pump when partly blocked — because starving a plunger pump causes cavitation, which damages it a different way. Water quality also matters if recovered water is being recycled, which is attractive where supply is limited but means the machine is deliberately pumping the dirtiest water on site. That is workable, but the separation and filtration then have to be designed for it rather than assumed. As a rule of thumb, the filter is part of the pump specification, not an accessory listed after it.

Q · 05 How do you size a vehicle-mounted unit?

Backwards from the payload, which surprises people who expect to start from the pump. A combination machine has to carry clean water out and recovered material back, and both are heavy — water is a tonne per cubic metre and wet silt is appreciably heavier. So the sum starts with the chassis' legal gross weight, subtracts the cab, body, tank, pump, reel and all the rest of the equipment, and whatever remains is what may be carried. That number then has to be split between clean water and recovered spoil, and the split determines the working pattern: a large clean-water tank means longer jetting between refills but less room for spoil, and vice versa. Two errors recur. The first is doing the sum empty — the machine weighs in legally as built and is overloaded the moment it is working, which is discovered at a weighbridge and cannot be fixed afterwards without removing capability. The second is ignoring axle distribution: the total can be within limits while the rear axle is over, because the tank and reel are behind the rear axle line and their contents are not. So tank position, baffling and the sequence in which water leaves and spoil arrives all matter. Decanting recovered water back out of the spoil tank helps materially here, because it means the tank is holding solids rather than liquid, which is the whole point of separating them.

Q · 06 What do you build, what is bought in — and what is claimed?

Divided honestly. What Neometrix provides: the machine design and integration — establishing the duty and matching pressure against flow to it, which is the decision the whole machine follows from; the pump and drive package with unloader, relief, pulsation control and regulation, and the inlet filtration that keeps the pump alive; the delivery end — lance, hose reel and the nozzle set chosen and documented as the tool kit it is; recovery and separation, sludge handling and decanting; the carrier or skid integration including the payload and axle-loading arithmetic done full rather than empty; the controls and the safety system — dead-man, anti-withdrawal, interlocks and guarding, sized against a reaction force calculated before the architecture was chosen; and the site survey, installation, commissioning, documentation, operator training, spares and AMC — including build to the customer's own specification. What is bought-in certified: the high-pressure plunger pump, the prime mover, the vacuum package and the chassis — proprietary products of established makers, integrated rather than imitated. What is the customer's: the site, the water supply, the material to be removed and its disposal route. And the record, stated plainly: equipment of this class has been quoted across high-pressure water jetting and desilting requirements for naval, municipal and industrial users. No delivered high-pressure water jetting or desilting machine is claimed; the class is engineered to order, around the deposit it has to remove.

↗

Three ways to get something clean from Neometrix.

Chemistry, dry abrasive, and water — different mechanisms, different problems left behind.

↗ Chemistry

Chemical Cleaning Bay

Dissolves the bond by immersion — and leaves effluent to treat.

↗ Dry abrasive

Shot Blasting & Peening

Media to recover and dust to contain — here it is water and solids instead.

↗ Gentle

Engine Compressor Washing Rig

One component, cleaned without damaging it — deliberately the opposite of this.

Browse all Neometrix product lines.

Get a quotation

Tell us what is stuck
and what it is stuck to.

The projects desk replies within two working days with a clause-by-clause compliance matrix and a budgetary quotation. Write to [email protected] or use the form.

Enquire — jetting & desilting Capability sheet (PDF) +91 7777 876 876

ISO 9001 / 14001 ENGINEERED TO ORDER — HIGH-PRESSURE WATER JETTING & DESILTING MACHINES PRESSURE CUTS IT LOOSE · FLOW CARRIES IT AWAY · RECOVERY DECIDES IF IT IS USEFUL ENGINEERED IN NOIDA · INDIA

Pressure cuts it loose. Flow is what carries it away.

Anyone can make water come out fast.

Pressure against flow

Reaction force first

Somewhere to put it

Cut it loose, carry it away, then put it somewhere.

High-Pressure Pump & Drive

Lance, Hose Reel & Nozzles

Recovery & Separation

Carrier, Control & Safety

Reference builds, sized to the deposit.

Where these machines go wrong

Same physics, four machines.

Vehicle-Mounted Combination Unit

Skid or Trailer Cleaning Machine

Shipboard Cleaning Set

Fixed Rinsing Installation

Wherever something will not simply wash off.

Common questions.

Three ways to get something clean from Neometrix.

Chemical Cleaning Bay

Shot Blasting & Peening

Engine Compressor Washing Rig

Tell us what is stuck
and what it is stuck to.

Similar Products

Share This Page

Pressure cuts it loose. Flow is what carries it away.

Anyone can make water come out fast.

Pressure against flow

Reaction force first

Somewhere to put it

Cut it loose, carry it away, then put it somewhere.

High-Pressure Pump & Drive

Lance, Hose Reel & Nozzles

Recovery & Separation

Carrier, Control & Safety

Reference builds, sized to the deposit.

Where these machines go wrong

Same physics, four machines.

Vehicle-Mounted Combination Unit

Skid or Trailer Cleaning Machine

Shipboard Cleaning Set

Fixed Rinsing Installation

Wherever something will not simply wash off.

Common questions.

Three ways to get something clean from Neometrix.

Chemical Cleaning Bay

Shot Blasting & Peening

Engine Compressor Washing Rig

Tell us what is stuckand what it is stuck to.

Similar Products

Share This Page

Tell us what is stuck
and what it is stuck to.