A Day In The Life Of Sourcing Pumps
The JWCS needs 3 pumps; one to push water across the RO membrane, one to move water from the permeate tank (clean RO produced water) to the treated tank (where the minerals have been dosed in), and one to push water to the coffee machine.
The first two were found and bought in the first two weeks, but the third one took a little longer to find.
It's not that the third pump was hard to find, it's just that the pumps I need don't come on the market super often, so I just had to be patient.
As I've said before, the idea of taking what was once a really expensive, highly engineered piece of kit and using it in a system that could never really justify buying new, but could greatly benefit from industrial-level reliability and performance, is kind of a fetish of mine.
I've done it with everything from high-altitude thermal vacuum chambers to the alternator on a Lexus for an exercise sled; I LOVE using badass rugged older gear in new projects.
The first step is to figure out what you actually need. In my case, the core requirement for the SanRemo Cafe Racer is supply between 29 and 65 psi and NSF 61.
Secondary to that was fitting in with the other pumps and having interchangeable parts where possible, so I knew I wanted a Grundfos.
That left me with looking for a pump in the CRN1S lineup, with anywhere from 5 to 10 stages, where each stage adds anywhere from 10-20 psi.
I had a few more restrictions, mostly from earlier decisions like circuit breaker/line reactor/VFD sizing. I knew I didn't need a huge pump (hell, this is overspec'd as is), and on the electrical side I'd sized for 0.5hp or lower.
What you and I might call a "pump" is, in industrial purchasing, actually a pump and a motor. The pump is the framework for moving the water, and the motor drives the pump. Everything has to match up in order for the unit to be useable.
The pump motor also had to be 60 Hz (obvi, using this in the US), 230V and 3 phase so we could control it with the VFD.
So there's our spec, which I wrote up into a `distribution-pump-spec.md' doc and fed it into a custom tool I built called 'ebay-finder' that helps me narrow down what I'm looking for.
I've dropped the actual doc in at the bottom so you can see what that looks like.
The tool returned 216 active matches, though only one scored higher than 60, which is usually what I look for. It missed the NSF61 plate, so when I opened that top listing (scoring 78), and saw it, then verified the rest of the pump's stats, I put in an offer.
Top 3 search results:
I opened the number one listing (scoring at 78, which is excellent), verified that the ebay-finder tool had missed the NSF61 marking, and submitted an offer.
The next day I woke up to a purchased pump. What did I buy?
Grundfos uses an alphanumeric system to tell you what you're getting with their pumps, in this case:
CRN1S-5 A-FGJ-G-E-HQQE
CRN1S-5 A FGJ G E HQQE
└────┬─┘ │ └┬┘ │ │ └┬─┘
family stages │ │ │ │ │
version │ │ │ │
connection │ │ │
material │ │
o-ring elastomer │
shaft seal
- CRN1S: The family of pumps with (relatively) low flow and a stainless steel base
- 5: 5 stages (the number of impellers)
- FGJ:
Flange/G (DIN-ANSI-JIS)a combined connection allowing the pump to be bolted to various international piping standards - G:
316L stainless steel, a material upgrade - E:
EPDM, standard for water applications and compatible with the E in the HQQE seal - HQQE - H = balanced cartridge, QQ = silicon carbide/silicon carbide faces, E = EPDM secondary seal.
This will easily provide what the SanRemo needs and more. At 3 gallons per minute it pushes ~110 feet of Total Dynamic Head, or about ~47 psi.
Now, any coffee machine geek knows that no coffee machine out there will use 3 gpm or anything close. Running a 3 group wide open and the hot water tap running will cost you well under 0.5 gpm.
So why use this pump? Stability. Industrial pumps are rated at higher flow rates than some $100 Amazon pump. This means when the Racer does demand any amount of water, the pressure doesn't sag. In fact, running the pump to deliver 47 psi is running it in its lazy zone; this thing is loafing even when the cafe's banging.
The bigger picture here for the Paleo Treats coffee experience is to deliver superb coffee effortlessly and fast. THAT'S why I'm overspec'ing these pumps.
Now, under $800 for this pump seems like a good deal, however... Since this is a custom skid and we're not ordering new from the factory (at something like $3k for a new pump vs the ~$730 I paid), I also have to factor in the costs for adapting from the 1" ports.
Assume that'll be another $200 or so, and I'll still have gotten a ripping deal on a monster that doesn't break a sweat when the line is 10 deep and they only ask for more, more, more...
As I was taught many many moons, ago: Proper prior preparation prevents piss poor performance
Be prepared!
Distribution Pump Spec Doc
Distribution pump for the water skid: T-102 → espresso machine + drinking water station. Driven by an existing VFD-103 (½ HP, 3-φ 230 V output, 60 Hz).
## 1. Pump
- **Grundfos CRN1S** [CRITICAL]
- Reject any other brand
- Reject any other Grundfos family: plain `CR` (cast iron), `CRI`, `CRT`, `CRNE` / `CRIE` / `CRE` (built-in VFD)
- **Stages: 5 to 10** [CRITICAL]
- Duty: 30 psi @ 3 gpm = ~70 ft TDH. CRN1S-5 delivers ~110 ft at 3 gpm
- CRN1S-12 and larger overload the ½ HP motor and VFD-103
## 2. Motor
- **3-phase, 230 V, 60 Hz, ½ HP** [CRITICAL] [VERIFY: photo]
- Reject single-phase, 50 Hz-only, 460 V-only, motors larger than ¾ HP
## 3. NSF/ANSI 61 [VERIFY: photo]
- Grundfos CRN catalog-level approval is sufficient
- Nameplate stamp preferred; EU-built units carry CE/EAC only — accept
## 4. Seal
- HQQE preferred (matches P-101 / P-102 spares)
- Any seal with EPDM (`-E-HQQE`) or FKM (`-V-HQQV`) acceptable
- Reject Buna-N (`B`)
## 5. Price
- **$700 – $1,500** used
- Above $1,600: buy new from PumpWorld for $1,953 (Grundfos PN `99915671`, CRN1S-8 baseline)
## 6. Search Keywords
- "Grundfos CRN1S"
- "Grundfos CRN1S-5"
- "Grundfos CRN1S-6"
- "Grundfos CRN1S-8"
- "Grundfos CRN1S-10"
- "Grundfos CRN1S A-FGJ"
- "Grundfos 99915671"
- "Grundfos 96515905"