CM, CME Horizontal Multistage Pumps

Grundfos CM and CME are horizontal multistage pumps for pressure boosting where there is no room for a vertical column. ForeverPure lists 586 configurations — 284 fixed-speed CM and 302 variable-speed CME — with motors from 4/7 to 8.6 HP.

CM or CME

Same hydraulics, different motor. CM runs at fixed speed and costs less to buy. CME carries an integrated Grundfos MGE variable-frequency motor that holds a pressure setpoint as demand changes — no external VFD, no extra panel space.

If the system sees variable demand — a building, an irrigation zone, a process that throttles — CME normally repays the difference in energy alone, because a fixed-speed pump throttled across a valve wastes the excess as heat. On flat continuous duty, CM is the better buy.

Materials

Construction	Where it fits
Cast iron	Clean, non-aggressive water — HVAC, general boosting
AISI 304 stainless	Potable water, food and beverage, washdown
AISI 316 stainless	Chlorides, RO permeate and concentrate, chemical duty

All three appear in this range. Choose on water chemistry first and price second — replacing a pitted 304 pump on chloride-bearing water costs more than specifying 316 at the outset.

Typical applications

Pressure boosting — commercial buildings, tank-fed systems, irrigation
Water treatment — filter feed, RO permeate transfer, CIP circuits
Industrial washdown and spray systems
HVAC — make-up and secondary circulation
Light process transfer where a vertical pump will not fit the space

Common questions

What is the difference between CM and CME?

CME has an integrated variable-speed motor and maintains constant pressure by itself. CM is fixed speed. The pump ends are the same.

CM or CR — which should I choose?

CR is vertical and reaches far higher pressures and flows; CM is horizontal, compact and suits smaller boosting duties where headroom is limited. If the duty point fits a CM, it is usually the cheaper and easier install.

Is CME suitable for constant-pressure systems?

Yes — that is its purpose. Set the pressure and the pump varies its own speed to hold it as demand changes.

Which material do I need for reverse osmosis?

316 stainless on anything touching concentrate or chloride-bearing feed. 304 is acceptable on permeate.

ForeverPure Corporation is an authorized Grundfos distributor. Send us a duty point or an existing model number and we will confirm the right configuration before you order — contact us.