ID

Inside diameter. All pipes are sized according to their inside diameter.

IPS

Iron Pipe Size (OD). Same as NPS. Standard pipe threads. Also Internal Pipe Swivel connection (female)

ISO

International Standards Organization based in Geneva Switzerland. Among the many standards it issues are pump and seal standards for the metric community.

ISO 9000

A series of five standards for developing a total quality management system. Developed by the International Standards Organization 

Immersion

A term referring to something submerged in water.

Impeller

Rotating wheel with vanes found inside a centrifugal pump. As it spins at high speed it draws fluids in and thrusts them under pressure to the discharge outlet.

Incomplete Combustion

A product of inadequate ventilation which restricts the flow of air into an appliance. This may lower oxygen content in the surrounding air.

Incoming Inlet Temperature

Temperature of water entering the tank.

Indirect Waste Pipe

Waste pipe used to convey gray water by discharging it into a plumbing fixture such as a floor drain.

Induction Motor

The most common type used in industry. Has a slippage of 2 to 5 percent compared to synchronous motors.

Influent

The stream entering a unit, stream or process, such as the hard water entering an ion exchange water softener.

Injection

The drawing of primary air into a gas burner by means of a flow of fuel gas.

Inlet

An entrance, opening, or aperture for the intake of fluid or gas.

In-line Pump

Small pump which pumps fluid through a line on which it is supported and mounted.

Input

The amount of fuel used by a water heater in a given period of time, usually 1 hr.

Input Rate

The quantity of heat or fuel supplied to an appliance, expressed in volume of heat units per volume of time (BTUs/hour).

Input Rating

The gas burning capacity of an appliance in BTU's per hour as specified by the manufacturer.

Insert Fittings

Fittings equipped with external, annular rings fir gripping, which are inserted into flexible rubber or plastic tubing as a connection.

Ion Exchange

A reversible process in which ions are released from an insoluble permanent material in exchange for other ions in a surrounding solution; the direction of the exchange depends upon the affinities of the ion exchanger for the ions present, and the concentrations of the ions in the solution.

Ionization

The process in which atoms gain or lose electrons; sometimes used as synonymous with dissociation, the separation of molecules into charged ions in solution.

Island Vent

An air admittance valve.

Isolation Mount

The four small rubber feet located beneath a whirlpool's pump base, or attached to the pulse canister assemblies, designed to reduce noise and vibration when the whirlpool is running.

Instantaneous Water Heater

A type of water heater that heats water as it flows through a heat exchanger coil.

Insular^®

Kohler's registered trade name for factory-installed insulation, which minimizes condensation on the outside of the tank when exposed to high humidity.

Insuliner^®

Kohler's Registered trade name for factory-installed tank insulation, which minimizes condensation on the outside of the tank (also known as tank sweating) when exposed to high humidity.

Integral Stops

Stops that allow the owner to shut off water supply at the faucet for maintenance without shutting off the water supply to the entire house.

Integral Vacuum Breaker

A device typically used in a sink or shower sprayer to keep water from back-flowing into the fresh water supply.

Interceptor

Device for separating grease and oil from drainage system. (See grease trap)

Isothermal

Action that takes place with no change in temperature.