Grundfos CM Horizontal Multistage Pumps

Grundfos CM is the horizontal half of the multistage range: a close-coupled, end-suction pump that lies on its feet rather than standing up, with the motor on one shaft so there is no coupling to align and no baseplate to grout. Both ports are NPT female
threads, so unlike CR and CRN nothing has to be ordered alongside the pump.

Three frames at 60 Hz - CM 3 at 16.4 GPM, CM 5 at 24.8 GPM and CM 10 at 52.8 GPM - with rated head to 306 ft on the tallest stack and motors from 0.58 to 8.4 HP on 115/230 V single phase or 208-230/440-480 V three phase, fixed per part number. Each frame comes in three material grades, and the grade decides more than corrosion resistance: CM-A in cast iron with 304 internals is rated 145 psi, while CM-I in all 304 and CM-G in all 316 are rated 232 psi.
Chlorides are what justify 316 - softened, brackish and coastal water, RO permeate and aggressive process liquids. Seals are AQQE in EPDM, rated to 248 F, or AQQV in FKM for mineral oils and liquids that attack EPDM.

Every part number is a complete pump with its close-coupled motor and shaft seal. Send us the peak flow, the inlet pressure, the target pressure, the elevation and the liquid and we will size it against the published Grundfos curve and tell you which grade the water calls for - call 1-888.510.4036.

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Grundfos CM 10-G Horizontal Multistage Pump, 316 Stainless Steel
Grundfos CM 10-G horizontal close-coupled multistage centrifugal pump with an all AISI 316 stainless liquid path, NPT threaded connections

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

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Grundfos CM 10-I Horizontal Multistage Pump, 304 Stainless Steel
Grundfos CM 10-G horizontal close-coupled multistage centrifugal pump with an all AISI 316 stainless liquid path, NPT threaded connections

Grundfos

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Grundfos CM 10-I Horizontal Multistage Pump, 304 Stainless Steel

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Grundfos CM 10-A Horizontal Multistage Pump, Cast Iron / 304 Stainless Steel
Grundfos CM 10-A horizontal close-coupled multistage centrifugal pump with a cast iron pump housing and AISI 304 internals, NPT threaded connections

Grundfos

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Grundfos CM 10-A Horizontal Multistage Pump, Cast Iron / 304 Stainless Steel

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Grundfos CM 5-G Horizontal Multistage Pump, 316 Stainless Steel
Grundfos CM 10-G horizontal close-coupled multistage centrifugal pump with an all AISI 316 stainless liquid path, NPT threaded connections

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Grundfos CM 5-G Horizontal Multistage Pump, 316 Stainless Steel

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Grundfos CM 5-I Horizontal Multistage Pump, 304 Stainless Steel
Grundfos CM 10-G horizontal close-coupled multistage centrifugal pump with an all AISI 316 stainless liquid path, NPT threaded connections

Grundfos

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Grundfos CM 5-I Horizontal Multistage Pump, 304 Stainless Steel

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Grundfos CM 5-A Horizontal Multistage Pump, Cast Iron / 304 Stainless Steel
Grundfos CM 10-A horizontal close-coupled multistage centrifugal pump with a cast iron pump housing and AISI 304 internals, NPT threaded connections

Grundfos

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Grundfos CM 5-A Horizontal Multistage Pump, Cast Iron / 304 Stainless Steel

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Grundfos CM 3-G Horizontal Multistage Pump, 316 Stainless Steel
Grundfos CM 10-G horizontal close-coupled multistage centrifugal pump with an all AISI 316 stainless liquid path, NPT threaded connections

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Grundfos CM 3-G Horizontal Multistage Pump, 316 Stainless Steel

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Grundfos CM 3-I Horizontal Multistage Pump, 304 Stainless Steel
Grundfos CM 10-G horizontal close-coupled multistage centrifugal pump with an all AISI 316 stainless liquid path, NPT threaded connections

Grundfos

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Grundfos CM 3-I Horizontal Multistage Pump, 304 Stainless Steel

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Grundfos CM 3-A Horizontal Multistage Pump, Cast Iron / 304 Stainless Steel
Grundfos CM 10-A horizontal close-coupled multistage centrifugal pump with a cast iron pump housing and AISI 304 internals, NPT threaded connections

Grundfos

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Grundfos CM 3-A Horizontal Multistage Pump, Cast Iron / 304 Stainless Steel

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Grundfos CM Horizontal Multistage Pumps

Grundfos · Horizontal Multistage

Grundfos CM Horizontal Multistage Pumps

Close-coupled, end-suction multistage pumps that lie on their feet rather than standing up. Three frames, three material grades, NPT threaded ports and nothing to order alongside.

168part numbers
16.4-52.8GPM rated flow
306 ftmaximum rated head
3material grades
51model and material pairs

The Horizontal Half Of The Multistage Range

Grundfos builds two multistage platforms for the same kind of duty. The vertical CR stands upright with its ports in line, which suits a tight floor plan under a high ceiling. The CM lies horizontal on its feet with the suction on the end of the pump, which suits the opposite: a plant room where headroom is short and floor space is not. The motor is close-coupled on one shaft, so there is no coupling to align and no baseplate to grout, and both ports are NPT female threads, so nothing has to be ordered alongside the pump.

We supply the full CM 3, CM 5 and CM 10 range in the correct US 60 Hz build — 168 part numbers across three frames and all three material grades, in AQQE or AQQV seals. Send us the flow, the required boost, the inlet pressure, the liquid and the available voltage and we will size it against the published Grundfos curve and give you the part number and lead time — call 1-888.510.4036.

Genuine Grundfos equipment, factory-new in original packaging — sold and supported by Watermain Supply, an independent industrial supplier.

Three Material Grades

On CM the material code is the decision that matters most. It sets the pressure rating, the temperature ceiling and the approvals — the frame only sets the flow.

Grundfos CM-A horizontal close-coupled multistage centrifugal pump, cast iron build

CM-A

Cast Iron / 304 · 40 part numbers

16.4/24.8/52.8 GPMrated flow
64-191 ftrated head
0.58 to 5.4 HPmotor range
145 psimax pressure

Cast iron pump housing, AISI 304 internals. Three frames at 60 Hz — CM 3 at 16.4 GPM, CM 5 at 24.8 GPM, CM 10 at 52.8 GPM — with rated head from 64 ft to 191 ft. Rated 145 psi maximum operating pressure.

Key specifications
  • Rated flow 16.4 / 24.8 / 52.8 GPM at 60 Hz; rated head 64-191 ft
  • 0.58 to 5.4 HP (P2), NEMA close-coupled motor, IP55
  • Maximum operating pressure 145 psi
  • AQQE seal to 194 °F; AQQV seal to 194 °F
  • WRAS, ACS, NSF61 drinking-water approvals
  • 40 part numbers; shipping weight 30-96 lb
Best forGeneral water transfer, pressure boosting, irrigation and washdown on clean potable water, and cooling loops where an all-stainless liquid path is not required and the lowest cost per GPM is.
CM 3-ACM 5-ACM 10-A
Grundfos CM-I horizontal close-coupled multistage centrifugal pump, 304 stainless build

CM-I

All AISI 304 · 64 part numbers

16.4/24.8/52.8 GPMrated flow
53-306 ftrated head
0.58 to 8.4 HPmotor range
232 psimax pressure

AISI 304 stainless throughout the liquid path. Three frames at 60 Hz — CM 3 at 16.4 GPM, CM 5 at 24.8 GPM, CM 10 at 52.8 GPM — with rated head from 53 ft to 306 ft. Rated 232 psi maximum operating pressure.

Key specifications
  • Rated flow 16.4 / 24.8 / 52.8 GPM at 60 Hz; rated head 53-306 ft
  • 0.58 to 8.4 HP (P2), NEMA close-coupled motor, IP55
  • Maximum operating pressure 232 psi
  • AQQE seal to 248 °F, 194 °F on CM 3-8, CM 3-9, CM 5-8 and CM 10-5; AQQV seal to 194 °F
  • WRAS, ACS, NSF61, UBA drinking-water approvals
  • 64 part numbers; shipping weight 32-107 lb
Best forPotable water boosting and transfer where iron pick-up is unacceptable, boiler feed and condensate, filtration and softening skids, and food and light process duty on clean, low-chloride supplies.
CM 3-ICM 5-ICM 10-I
Grundfos CM-G horizontal close-coupled multistage centrifugal pump, 316 stainless build

CM-G

All AISI 316 · 64 part numbers

16.4/24.8/52.8 GPMrated flow
53-306 ftrated head
0.58 to 8.4 HPmotor range
232 psimax pressure

AISI 316 stainless throughout the liquid path. Three frames at 60 Hz — CM 3 at 16.4 GPM, CM 5 at 24.8 GPM, CM 10 at 52.8 GPM — with rated head from 53 ft to 306 ft. Rated 232 psi maximum operating pressure.

Key specifications
  • Rated flow 16.4 / 24.8 / 52.8 GPM at 60 Hz; rated head 53-306 ft
  • 0.58 to 8.4 HP (P2), NEMA close-coupled motor, IP55
  • Maximum operating pressure 232 psi
  • AQQE seal to 248 °F, 194 °F on CM 3-8, CM 3-9, CM 5-8 and CM 10-5; AQQV seal to 194 °F
  • WRAS, ACS, NSF61, UBA drinking-water approvals
  • 64 part numbers; shipping weight 32-107 lb
Best forSoftened, brackish and chloride-bearing water, coastal sites, reverse osmosis feed and permeate, chemical dosing, and food, beverage and pharmaceutical process duty.
CM 3-GCM 5-GCM 10-G

CM-A vs CM-I vs CM-G

Pick the grade on the liquid and the pressure, then the frame on the flow, then the stack on the head.

  CM-A CM-I CM-G
Pump housing Cast iron, EN-GJL-200 AISI 304 AISI 316
Liquid path Cast iron and 304 All 304 All 316
Max operating pressure 145 psi 232 psi 232 psi
AQQE temperature ceiling 194 °F 248 °F, 194 °F on CM 3-8, CM 3-9, CM 5-8 and CM 10-5 248 °F, 194 °F on CM 3-8, CM 3-9, CM 5-8 and CM 10-5
AQQV temperature ceiling 194 °F 194 °F 194 °F
Drinking-water approvals WRAS, ACS, NSF61 WRAS, ACS, NSF61, UBA WRAS, ACS, NSF61, UBA
Stage options, CM 3 4 8 8
Stage options, CM 5 4 7 7
Stage options, CM 10 3 5 5
Part numbers 40 64 64
Quick rule. Chlorides decide between 304 and 316 — the molybdenum in 316 resists chloride pitting and 304 has none, so softened, brackish and coastal water calls for CM-G. Iron pick-up decides between cast iron and stainless: on potable water that sits idle, CM-A can bloom rust into the first draw where CM-I will not. And if the system runs above 145 psi, cast iron is out on the pressure rating alone.

Published Duty Points

Rated flow, rated head and pressure rating as Grundfos publishes them for the US 60 Hz build, for every model in every material. These are the nominal figures, not a curve.

Model Grade Rated flow (GPM) Rated head (ft) Rated head (m) Max pressure (psi)
CM 3-2 CM-A 16.4 64 19.51 145
CM 3-3 CM-A 16.4 97 29.69 145
CM 3-4 CM-A 16.4 131 39.86 145
CM 3-5 CM-A 16.4 164 50.03 145
CM 3-2 CM-I 16.4 63 19.1 232
CM 3-3 CM-I 16.4 96 29.27 232
CM 3-4 CM-I 16.4 129 39.45 232
CM 3-5 CM-I 16.4 163 49.62 232
CM 3-6 CM-I 16.4 196 59.8 232
CM 3-7 CM-I 16.4 230 69.97 232
CM 3-8 CM-I 16.4 263 80.15 232
CM 3-9 CM-I 16.4 296 90.32 232
CM 3-2 CM-G 16.4 63 19.1 232
CM 3-3 CM-G 16.4 96 29.27 232
CM 3-4 CM-G 16.4 129 39.45 232
CM 3-5 CM-G 16.4 163 49.62 232
CM 3-6 CM-G 16.4 196 59.8 232
CM 3-7 CM-G 16.4 230 69.97 232
CM 3-8 CM-G 16.4 263 80.15 232
CM 3-9 CM-G 16.4 296 90.32 232
CM 5-2 CM-A 24.8 70 21.36 145
CM 5-3 CM-A 24.8 108 32.77 145
CM 5-4 CM-A 24.8 145 44.19 145
CM 5-5 CM-A 24.8 182 55.6 145
CM 5-2 CM-I 24.8 70 21.37 232
CM 5-3 CM-I 24.8 108 32.78 232
CM 5-4 CM-I 24.8 145 44.2 232
CM 5-5 CM-I 24.8 182 55.61 232
CM 5-6 CM-I 24.8 220 67.02 232
CM 5-7 CM-I 24.8 257 78.44 232
CM 5-8 CM-I 24.8 295 89.85 232
CM 5-2 CM-G 24.8 70 21.37 232
CM 5-3 CM-G 24.8 108 32.78 232
CM 5-4 CM-G 24.8 145 44.2 232
CM 5-5 CM-G 24.8 182 55.61 232
CM 5-6 CM-G 24.8 220 67.02 232
CM 5-7 CM-G 24.8 257 78.44 232
CM 5-8 CM-G 24.8 295 89.85 232
CM 10-1 CM-A 52.8 65 19.69 145
CM 10-2 CM-A 52.8 128 39.01 145
CM 10-3 CM-A 52.8 191 58.34 145
CM 10-1 CM-I 52.8 53 16.12 232
CM 10-2 CM-I 52.8 116 35.44 232
CM 10-3 CM-I 52.8 180 54.77 232
CM 10-4 CM-I 52.8 243 74.09 232
CM 10-5 CM-I 52.8 306 93.42 232
CM 10-1 CM-G 52.8 53 16.12 232
CM 10-2 CM-G 52.8 116 35.44 232
CM 10-3 CM-G 52.8 180 54.77 232
CM 10-4 CM-G 52.8 243 74.09 232
CM 10-5 CM-G 52.8 306 93.42 232
Reading these figures. Head is stated in feet; divide by 2.31 for psi, or multiply psi by 2.31 for feet. Elevation costs 0.433 psi per foot of lift. The cast-iron rows read slightly higher than their stainless equivalents on CM 3 and CM 5, and noticeably higher on CM 10-1 — that is what Grundfos publishes, not a rounding artefact, which is why each grade carries its own figures. For the flow and head at a specific point on the curve, request the manufacturer curve for the part number and we will send it.

Sizing a CM

A pump curve plots what the pump adds to the pressure already at its inlet. Size on the boost required, never on the pressure wanted.

  1. Find the peak flow. For residential, count water supply fixture units and convert with the Hunter curve in IPC Table 604.3. For light commercial, use the IAPMO Water Demand Calculator. Guessing high here is the most expensive mistake in the exercise.
  2. Work out the required boost. Required boost = target pressure at the highest fixture + 0.433 psi per foot of elevation + friction loss through pipe, fittings and any treatment − the inlet pressure you can count on at peak demand.
  3. Worked example. A building wants 45 psi at a fixture 30 ft above the pump. Friction through the riser and meter is 7 psi. The main holds 38 psi at peak. Required boost = 45 + (30 × 0.433) + 7 − 38 = 27 psi, which is 62 ft of head. At 25 GPM that lands on the shortest CM 5 stack.
  4. Pick the frame from the flow. 16.4 GPM for CM 3, 24.8 GPM for CM 5, 52.8 GPM for CM 10. Then choose the stage count that covers the head. Going up a frame to cure weak pressure at a single outlet is the usual mis-buy.
  5. Choose the grade on the liquid, then check the pressure. Chlorides mean CM-G. Potable water with no iron pick-up allowed means CM-I. Otherwise CM-A is the lowest cost — provided the system stays under its 145 psi rating, against 232 psi on the stainless builds.
  6. Check the liquid temperature against the seal. On the stainless builds AQQE reaches 248 °F and AQQV 194 °F; on cast iron both are 194 °F. The seal changes a published limit, so it is a specification decision rather than a preference.
  7. Confirm the electrical supply. 115/230 V single phase or 208-230/440-480 V three phase, fixed per part number and not interchangeable.
The 70 percent rule. If the duty point sits above about 70 percent of a model's rated head, step up to the next stack. It leaves room for pipe scaling, a dirty strainer and the day the inlet pressure sags, and it keeps the pump off the flat end of its curve where small pressure changes cause large flow swings.

Selection Guide

A starting point, not a substitute for sizing. Send us the numbers and we will confirm the part number.

Application Typical demand Start with Notes
General transfer and boosting, clean water 15-17 GPM CM 3-A Lowest cost per GPM. Confirm the system stays under 145 psi.
Potable boosting, no iron pick-up 15-17 GPM CM 3-I No cast iron in the liquid path, and 232 psi rather than 145 psi.
Softened or coastal water 15-17 GPM CM 3-G 316 for chloride resistance. The 304 build risks pitting.
Irrigation and washdown 22-26 GPM CM 5-A Check the washdown chemistry against the seal before ordering.
Boiler feed and condensate 22-26 GPM CM 5-I AQQE to 248 °F. Check the model — the tallest stacks fall back.
RO feed and permeate 22-26 GPM CM 5-G 316 throughout. Permeate is aggressive despite being clean.
Cooling and process transfer 45-53 GPM CM 10-I Five stage options against three on the cast-iron build.
Chemical dosing Any CM-G Send the liquid and concentration — the seal may decide it, not the stainless grade.
Swinging demand, constant pressure Any CME, not CM CM is fixed speed. CME is the same hydraulics with an integrated drive.

What The CM Build Gives You

Horizontal, Close-Coupled

Motor and pump end on a single shaft, mounted on feet. Nothing to align on installation, no separate baseplate to grout, and a low profile that fits under pipework and mezzanines where an upright CR will not.

Threaded Ports, Nothing Extra

NPT female on suction and discharge across every build. No companion flanges, no Victaulic couplings, no gaskets to order with the pump — which is a real difference from CR and CRN, where the mating hardware is a separate line on the order.

Three Material Grades

Cast iron with 304 internals, all 304, or all 316. The grade is a specification decision, not a finish: it sets the pressure rating and the drinking-water approvals as well as the corrosion resistance.

Head By Stage Count

Multistage hydraulics set head by the number of chambers at a fixed frame flow, so the duty point is reached by stacking stages rather than oversizing the motor. The footprint barely changes between the shortest and tallest stack.

Two Seal Options

AQQE in EPDM or AQQV in FKM, both with carbon against silicon carbide faces. EPDM is the standard water seal and carries the higher temperature ceiling; FKM is for mineral oils, fuels and liquids that attack EPDM.

Drinking Water Approvals

WRAS, ACS, NSF61, UBA on the stainless builds and WRAS, ACS, NSF61 on cast iron. The marks are quoted as Grundfos publishes them — worth checking against your specification, since the two lists are not identical.

IP55, NEMA Mounting

Enclosure class IP55 with NEMA close-coupled motors and a US 60 Hz build. The metric 50 Hz equivalents look identical on paper and will not perform to the same curve.

Curve Tolerance ISO9906:2012 3B

Published duty points carry the grade 3B tolerance band, the same basis as the rest of the Grundfos multistage range, so a CM and a CR figure can be compared directly.

CM Against The Rest Of The Range

Four answers to overlapping duties. The figures below come from our own product data for each range, not from memory.

  CM CME CR / CRI / CRN CRE / CRIE / CRNE
Orientation Horizontal, on feet Horizontal, on feet Vertical, in-line ports Vertical, in-line ports
Speed control Fixed speed Integrated drive Fixed speed Integrated MLE drive
Connections NPT threaded, nothing extra NPT threaded Oval, Victaulic or ANSI flanged Oval NPT or ANSI flanged
Companion hardware None needed None needed Separate on grooved and flanged Separate on flanged
Grades offered Cast iron/304, 304, 316 Cast iron/304, 304, 316 Cast iron/304, 304, 316, titanium Cast iron/304, 304, 316
Best for Short headroom, simple install Short headroom, swinging demand Tight floor plan, higher pressure Tight floor plan, swinging demand

Where CR still wins. On pressure and reach. The vertical range runs to 362 psi on its flanged builds and far higher heads than any CM stack, and it offers a titanium grade the CM range does not. If the duty needs either, the CM is the wrong platform however convenient the footprint. And where the demand swings rather than sitting at one point, a fixed-speed CM against a throttling valve is the expensive way to do it — that is a CME question.

Documentation & Parts

Published Grundfos literature for the range, linked on every product page in this collection.

CM-A, CM-I, CM-G Data Booklet (60 Hz, US)

Open the PDF

CM Installation and Operating Instructions

Open the PDF

CM, CME Data Booklet

Open the PDF

CM Quick Guide

Open the PDF

CM, CME and Boosters Service Kit Catalogue

Open the PDF

Drawings & Submittals

Dimensional drawings and a factory submittal package are available on request — email sales@watermainsupply.com with the part number.

Grundfos publishes CM curves as graphics rather than tabulated points, so the duty points on this page are the nominal figures from the technical data. For the curve itself, ask and we will send the manufacturer curve for your part number.

Why Source Grundfos CM from Watermain Supply

We Pick The Grade Properly

Send the water analysis. Chloride, temperature and what the system does when it sits idle decide between cast iron, 304 and 316 — and the grade also decides the pressure rating, which catches people out.

We Size On The Boost

Send the inlet pressure, the target pressure, the elevation and the peak flow. We size on what the pump has to add, which is the number that picks the model — not the pressure you want at the tap.

The Right US Build

60 Hz hydraulics, NEMA close-coupled motors and the voltage and phase your service actually has. Voltage is fixed per part number, so getting it right at the order is the only chance to get it right.

Engineering-Led Selection

We work from the published Grundfos curve and the limits table, and we will tell you when the seal, not the stainless grade, is what rules a liquid out.

Multi-Brand Perspective

If CM is not the right fit, we will say so and quote the one that is — a vertical CR where the pressure demands it, a CME where the demand swings, or a pump from another manufacturer.

Parts & Aftermarket

Seal kits, neck rings, motor bearing kits and wear parts identified from the pump nameplate, for pumps we supplied and for ones we did not.

Frequently Asked Questions

The questions that come up most often on the phone about CM selection.

What is the difference between CM-A, CM-I and CM-G?

The materials, and two things that follow from them. CM-A has a cast iron pump housing with AISI 304 internals. CM-I is AISI 304 throughout the liquid path. CM-G is AISI 316 throughout. The cast iron build is rated 145 psi maximum operating pressure and the two stainless builds are rated 232 psi, so the material also sets the pressure ceiling. The cast iron build also carries WRAS, ACS and NSF61 approvals where the stainless builds add UBA.

Do the three materials share the same hydraulics?

The stainless builds do: Grundfos publishes an identical rated head for the 304 and 316 version of every model, and we checked all eighteen where both are published. Cast iron does not quite. It reads slightly higher on CM 3 and CM 5 and noticeably higher on CM 10-1, 19.69 m against 16.12 m, so each material carries its own figures on its own listing rather than a shared table.

How is CM different from the vertical CR range?

Orientation and footprint. A CR stands upright with suction and discharge in line at the same level, which suits a tight floor plan with headroom. A CM lies horizontal on its feet with the suction on the end of the pump, which suits a plant room where headroom is short and floor space is not. The motor is close-coupled on a CM, so there is no coupling to align and no baseplate to grout.

What does the number in CM 3 or CM 10 mean?

It is Grundfos's nominal duty in cubic metres per hour, not a GPM figure. CM 3 is rated 16.4 GPM, CM 5 is 24.8 GPM and CM 10 is 52.8 GPM at 60 Hz. Pick the frame from the flow you need, then the stage count from the head. Sizing from the model number is the most common mistake on this range.

What is the difference between AQQE and AQQV seals?

The rubber, and the temperature ceiling that follows. AQQE uses EPDM and AQQV uses FKM, both with carbon against silicon carbide faces. On the stainless builds AQQE is rated to 248 °F against 194 °F for AQQV, so EPDM is the standard water seal and FKM is for mineral oils, fuels and liquids that attack EPDM. On the cast iron build both seals are 194 °F. The tallest stacks in each family also fall back to 194 °F on AQQE.

Will a bigger CM give me more pressure?

It gives more flow at the same head, which is usually the real problem. If several outlets running together make the pressure sag, the system is short of flow and a larger frame fixes it. If one outlet alone is weak, head is what is missing and a taller stack in the same frame is the answer. Stepping up a frame to cure a pressure complaint is the usual mis-buy.

Is the curve the pressure I get at the outlet?

No. A pump curve plots what the pump adds to the pressure already at its inlet. On a city main holding 40 psi, a pump adding 60 psi gives about 100 psi at the outlet. On a gravity-fed tank the inlet contributes almost nothing and the curve is close to what you get. Size on the boost required, not the pressure wanted.

What connections do these use?

NPT female threads on both ports, on every build. There is no flanged or grooved option and nothing to order alongside, unlike CR and CRN where companion connections are separate. Ports are 1 in on CM 3 and 1-1/2 in on CM 10; CM 5 is the exception, with a 1-1/4 in suction and a 1 in discharge.

What voltages are available?

115/230 V single phase and 208-230/440-480 V three phase, fixed per part number. Single-phase and three-phase units are not interchangeable, so confirm the supply before ordering. Grundfos also fits a different motor to each: CM 3-2 is 0.8 HP single phase and 0.58 HP three phase, with the hydraulics unchanged.

Are these variable speed?

No, these are fixed-speed pumps. For the same hydraulics with an integrated variable-speed drive and setpoint control, the equivalent is the CME range. A fixed-speed CM is the better buy where the duty genuinely runs at one point; a CME earns its premium where demand swings.

Ready to Size Your CM?

Send us the peak flow, the inlet pressure you can count on, the target pressure, the elevation, the liquid and the available voltage. We will respond with a sized selection, the material grade, the matching part number and lead time.

1-888.510.4036 Email sales@watermainsupply.com Request a Quote
Technical data on this page is taken from Grundfos U.S. 60 Hz product literature and is subject to change by the manufacturer. Confirm against the current installation manual and pump curve before specifying.
Grundfos, CM, CME, CR, CRI, CRN, CRT, CRE, CRIE and CRNE are trademarks of Grundfos Holding A/S, used here for product identification only.
Watermain Supply is a DBA of E4 Industrial LLC, an independent industrial supplier based in Houston, Texas.