Grundfos CME 10-G Horizontal Multistage Pump, 316 Stainless Steel

Horizontal, multistage centrifugal pump with the motor close-coupled to the pump end and the suction port on the end of the pump. CME is the CM pump end with an MLE motor on top: a motor with the frequency converter built into its terminal box, so the pump varies its own speed instead of running flat out against a throttling valve. It lies on its feet on a horizontal base, which suits a plant room where headroom is short and floor space is not.

A pump curve plots what the pump adds to the pressure already at its inlet, not the pressure you will read at the outlet. On a city main holding 40 psi, a pump adding 60 psi gives about 100 psi downstream. On a gravity-fed tank the inlet contributes almost nothing and the curve is close to what you get. Size on the boost required, then let the drive hold it.

The CME 10 frame is rated at 52.8 GPM. The family number is Grundfos’s nominal duty in cubic metres per hour, not a GPM figure — size the pump from the rated head table below, not from the model number.

5 models are offered, from CME 10-1 to CME 10-5, covering 1-1/2 to 7-1/2 HP on NEMA close-coupled motors. Adding stages raises head at the same flow without changing the footprint. Connections are 1-1/2 in NPT female suction and discharge, and the pump is rated 232 psi maximum operating pressure.

Why 316 rather than 304. The hydraulics are identical: Grundfos publishes the same rated head for the -I and -G builds of every model. What changes is corrosion resistance. The molybdenum in AISI 316 resists chloride pitting, which 304 does not, so the -G build is the grade for softened, brackish and chloride-bearing water. Where chlorides are not the issue, the -I build does the same hydraulic job for less.

• 316 Stainless Steel — AISI 316 stainless throughout the liquid path.
• Horizontal close-coupled build — motor and pump end on one shaft, on feet, so no coupling alignment and no separate baseplate to grout.
• Multistage hydraulics — head is set by stage count at a fixed frame flow, so the duty point is chosen without oversizing the motor.
• Frequency converter built into the motor — no separate drive panel, no drive-to-motor cable run and no commissioning step to tell a generic drive what motor it is driving.
• 2900-4000 rpm operating speed range — the drive works above and below the fixed 3480 rpm a CM turns, so one pump covers a band of duty rather than a single point.
• Soft starting on every start — ramping up under drive control takes the mechanical shock off the coupling and the water-hammer shock off the pipework.
• Cartridge-format shaft seal — AQQE or AQQV, replaced without setting the seal by hand.
• WRAS, ACS, NSF61, UBA approvals for drinking water contact.
• 232 psi maximum operating pressure on this material build.
• 1-1/2 in NPT female suction and discharge — threaded, so no companion flanges to order.

• AQQE — EPDM. Carbon against silicon carbide with an EPDM O-ring. The standard water seal: potable water, hot water and glycol. Mineral oils need AQQV.
• AQQV — FKM. Carbon against silicon carbide with an FKM O-ring, for mineral oils, fuels and liquids that attack EPDM. Note that FKM carries the lower temperature ceiling of the two.

• AQQE — −4 °F to 248 °F on CME 10-1, CME 10-2, CME 10-3, CME 10-4.
• AQQE — −4 °F to 194 °F on CME 10-5.
• AQQV — −4 °F to 194 °F.

In the Grundfos type key the final letter is the rubber: E = EPDM, V = FKM. The seal is a specification decision, not a preference — it changes the published temperature limit.

• Softened, brackish and chloride-bearing water, where 304 would be at risk of pitting
• Coastal and marine-adjacent installations
• Reverse osmosis feed and permeate, demineralised and deionised water
• Chemical dosing where the rate is trimmed by speed rather than by a valve
• Food, beverage and pharmaceutical process duty

Select the HP and voltage, then the seal, then the model. Each combination is a distinct Grundfos part number, listed in the table above and shown in the SKU of the selected variant.

The picker shows only the combinations Grundfos publishes.