Hydro jetting glossary

A–ZTerms

ABS

Acrylonitrile butadiene styrene, a black plastic drain pipe common in Canadian homes from about the 1970s onward. Generally tolerates jetting at appropriate pressure.

Access point

Any opening used to get a tool into a drain: a cleanout, fixture drain, toilet flange, roof vent, manhole or interceptor.

Asbestos-cement pipe

A mid-century pipe of cement reinforced with asbestos fibres, used in some municipal and service lines. Can be cleaned, but abrasive tools should be avoided.

Backwater valve

A device on the building drain with a flap that closes to stop sewage flowing back into the house from the main. Jetting is done downstream of it or with the flap removed and reinstalled.

Bell (hub)

The enlarged end of a pipe section that receives the next section. Clay and cast iron bells are common points for cracks and root entry.

Belly (sag)

A section of pipe that has dipped below its intended slope and holds standing water, grease and debris. Jetting clears it temporarily; it keeps collecting.

Bituminous fibre pipe (Orangeburg)

Mid-20th-century pipe made of wood fibre and pitch. It softens and deforms with age and needs great caution when cleaned.

Building drain

The lowest horizontal drain inside the building that collects waste from the stacks and carries it out through the foundation.

Building sewer

The pipe from the foundation wall to the municipal connection. Often called the main line or lateral by homeowners.

Camera inspection

A video inspection of the pipe interior using a push camera or crawler, usually with a footage counter and locator. The basis of camera-first cleaning.

Cast iron

A heavy metal drain pipe common inside older homes. Corrodes internally, forming tuberculation, and can thin at the bottom over decades.

Caustic drain cleaner

An alkaline drain opener, usually based on sodium or potassium hydroxide (lye), that turns fats into soap and breaks down hair. Corrosive; tell a contractor if one is in the line before jetting.

CIPP (cured-in-place pipe)

A trenchless repair in which a resin-saturated liner is inserted and cured inside the old pipe. Requires thorough cleaning first.

Cleanout

A capped fitting that gives direct access to a drain for cleaning tools. A usable cleanout is the biggest factor in jetting cost and cleanliness.

Combination truck (jet-vac)

A truck carrying a high-flow jetter and a vacuum system, used to clean mains and large lines and remove debris at a manhole.

Confined space

An enclosed space not designed for occupancy with restricted entry and possible hazardous atmospheres, such as a manhole or interceptor vault. Entry is regulated work.

Dead-man control

A control that stops the jetter's water flow as soon as the operator releases it, such as a foot pedal. A key safety feature on professional rigs.

Descaling

Removing mineral scale or tuberculation from a pipe wall with chain, abrasive or carbide tools, often before lining cast iron.

Drain bladder (blow bag)

A rubber bladder on a garden hose that swells to seal a pipe and pushes water against a clog in pulses. It pressurizes the line rather than scouring it.

Flow (gpm)

The volume of water a jetter delivers, in US gallons per minute. Flow carries debris away and provides nozzle thrust.

Flushing nozzle

A nozzle with shallow-angle rear jets only, designed to pull hard and move sand, silt and loose debris along the invert.

FOG

Fats, oils and grease: the main cause of kitchen and restaurant drain blockages, and a common subject of municipal sewer-use bylaws.

Footage counter

A meter on a camera or hose reel showing how far the camera or nozzle is from the access point.

Grease interceptor

A tank or device that separates fats and solids from commercial kitchen wastewater before it reaches the sewer. Pumped out on a schedule; also called a grease trap.

Hot-water jetter

A jetter that heats its water before it leaves the nozzle, used for hardened grease and frozen lines.

Hydraulic horsepower

A measure of the water energy a jetter delivers, calculated as psi multiplied by gpm, divided by 1,714.

Hydro blasting

Industrial water jetting at pressures commonly 10,000 psi and above, used to clean heat exchangers, tanks and process equipment and to strip coatings. A separate trade from sewer jetting.

Hydro excavation (hydrovac)

Digging with pressurized water and a vacuum truck, used to expose buried utilities safely. It digs soil; it does not clean pipe.

Hydro jetting

Cleaning drain and sewer pipes with high-pressure water from a nozzle whose rear jets propel it and scrub the wall while the flow carries debris away.

Hydrogen sulphide (H₂S)

A toxic sewer gas with a rotten-egg smell that dulls the sense of smell at higher concentrations. A key confined-space hazard.

Injection injury

An injury in which a high-pressure fluid jet penetrates skin and forces fluid into tissue. A surgical emergency even when the wound looks small.

Invert

The inside bottom of a pipe, where flow runs and sediment settles.

Iron ochre

A slimy orange-brown deposit formed by iron bacteria in iron-rich groundwater. It can clog weeping tile, filter fabric and sump pumps.

Jet angle

The angle between a rear jet and the pipe's centreline. Shallow angles pull harder; wider angles scrub the wall more.

Jetter hose

Reinforced high-pressure hose that carries water from the pump to the nozzle, sized to the pipe and pump flow.

Lateral

The service pipe connecting a building to the municipal sewer main. Ownership may be split between owner and municipality.

Leader (nozzle guide)

A short flexible or rigid section ahead of or behind a nozzle that helps keep it centred and prevents it turning around in larger pipe.

Main (sewer main)

The municipal sewer pipe, usually under the street or lane, that collects flow from many laterals.

NASSCO PACP

The Pipeline Assessment Certification Program from NASSCO, a widely used standard for coding defects found in sewer camera inspections.

Nozzle flip

When a jetting nozzle turns around in the pipe and travels back toward the access point while still firing. A serious injury risk.

Offset joint

A joint where one pipe section has shifted relative to the next, creating a step that catches debris and tools.

Orifice

A small hole in a nozzle through which water exits as a jet. Orifice size must match the pump's rating.

Penetrator nozzle

A nozzle with a forward jet plus rear jets, used to open a fully stopped line.

Pressure (psi)

Pounds per square inch: how hard water is pushed. Determines jet velocity and cutting force.

Pulsation

A jetter feature that makes the hose vibrate slightly to reduce friction and help it travel through bends and long runs.

PVC

Polyvinyl chloride, a white or green plastic sewer pipe common in building sewers and laterals from about the 1970s onward.

Root-cutting nozzle

A jetter nozzle with water-driven blades or cutting action designed to remove roots from pipe joints.

Rotating nozzle

A nozzle whose head spins, sweeping its jets around the full pipe circumference. The usual choice for grease.

SDR 35

A wall-thickness class of PVC sewer pipe (standard dimension ratio 35) commonly used for buried gravity laterals, usually green or cream with gasketed joints.

Sonde

A small transmitter in a camera head or on a nozzle that a locator above ground can find, marking position and depth.

Stack

A vertical drain or vent pipe in a building. The base of the stack is a common cleanout location.

Sump pit

A basin in the basement floor that collects water from the weeping tile, with a pump that lifts it outside. Jetting water from weeping tile returns here.

Triplex pump

A three-plunger positive-displacement pump, the common pump type on professional jetters.

Tuberculation

Rust nodules that build up inside cast iron pipe, narrowing the bore and roughening the wall.

Vitrified clay pipe

Fired clay sewer pipe with a hard, glazed wall, common in older laterals. Handles jetting when sound; joints are the weak points.

Weeping tile

A perforated foundation drain beside the footings that collects groundwater and carries it to a sump pit or, in some older homes, the sewer. Cleaned with low-pressure jetting.

Winterization

Protecting a jetter from freezing by heating, draining or circulating antifreeze through the pump and lines.