F-1031, Section 2112
Page 4 of 15
Introduction
This instruction contains information needed for the operation and maintenance of CR/CRU/CRU-2 Series centrifugal
pumps.
General Description
The CR/CRU-1/CRU-2 Series fire pumps are single stage, vertically-split and designed to operate from a water tank,
hydrant or from draft. They are designed for direct-drive (Model CR/CRU-1/CRU-2) or can be driven via a chain driven QA
transmission (CRQA), a chain-driven QB Transmission (CRQB), a chain-driven QC Transmission (CRU-
QC2/CRQC/CRUQC-2 with Bell Housing Adapter) or a chain-driven C21 Transmission (CRUC21-2).
Components
Body Assembly
The body assembly includes the volute body, intake and
discharge adapters and related parts. These parts are
available in either cast iron or bronze (except CRU-2).
Impeller Shaft Assembly
The impeller shaft assembly consists of a bronze impeller
mounted on a stainless steel shaft, bronze wear rings,
mechanical seal and related parts. The impeller is
mechanically and hydraulically balanced and the impeller
shaft is supported by ball bearings.
Mechanical Seals
Mechanical seals are standard on CR series pumps.
A mechanical seal consists of a flat, highly polished
(lapped), spring-fed carbon ring that is sealed to and
rotates with the impeller shaft. It presses against a highly
polished (lapped), silicone carbide, stationary ring that is
sealed in the pump body. This seals the shaft and pre-
vents air from entering and water from leaving.
A mechanical seal does not leak or drip water, even when
pumping.
Anodes
Options
Overheat Protection Manager (OPM)
As additional corrosion protection for iron body pumps,
Waterous has available zinc anodes to fit any unused
opening in the intake fitting. Anodes provide an additional
sacrificial zinc surface to the water to supplement the zinc
intake screens.
The Overheat Protection Manager (OPM) acts as a safety
device by releasing hot water to the ground or back to the
water tank from the discharge area of the pump.
