If yours is not here, call. Sizing conversations are the part of this we are good at.
What is the difference between CR, CRI and CRN?
Metal. All three are the same vertical multistage pump end with the same motor options. CR has a cast iron pump head and base with AISI 304 internals; CRI is all AISI 304; CRN is all AISI 316. Stage counts, motor sizes and hydraulics are the same across the three.
Do I need 316, or is 304 enough?
Chloride is the deciding factor. AISI 304 handles ordinary potable and process water indefinitely; it pits in salt-bearing water. Softened water, brackish or coastal supply, reverse osmosis permeate and most chemical dosing call for 316. Send the water analysis with the chloride concentration and temperature and we will confirm the grade.
What is the difference between these and CRE, CRIE and CRNE?
The drive. CR, CRI and CRN are fixed-speed pumps on a standard motor; you add a starter, and a VFD if you want speed control. CRE, CRIE and CRNE are the same pump ends with a Grundfos MLE motor that carries the frequency converter and a control panel inside it. If you want constant pressure, the E version is usually one machine instead of two.
Which seal should I pick, HQQE or HQQV?
Both are cartridge seals with silicon-carbide faces; the last letter is the elastomer. E is EPDM, the default for water. V is FKM, for liquids EPDM does not suit. If you are pumping water, HQQE.
What does the second number in the model mean?
Stage count. CR 5-10 is the 5 frame with ten stages. More stages means more head at the same flow without changing the footprint, so a system can be re-tuned by changing the stack rather than the whole pump. The first number is Grundfos's nominal duty in cubic metres per hour, not a GPM rating.
Will one of these lift water from a tank below the pump?
No. A vertical multistage pump is not self-priming and will not pull a suction lift. It needs flooded suction or a positive inlet pressure.
Is the oval-flange version interchangeable with the ANSI flanged one?
No. They are different part numbers with different pressure ratings and different connections, and they are not swapped in the field. Decide the connection before you order.
Can I add a variable frequency drive later?
Yes — a fixed-speed CR, CRI or CRN will run on an external VFD, and that is a common retrofit. Whether it is cheaper than buying the E version depends on the panel, the cabling and who commissions it. Ask us to price both.
What is the ODP option?
Open drip-proof motor enclosure, as against the standard totally enclosed fan-cooled (TEFC). ODP suits clean, dry, indoor installations and is offered on part of the 10 frame.
Are these certified for drinking water?
Yes — NSF/ANSI 61 for drinking water contact.
