Grundfos non-code diaphragm tanks for Hydro Multi booster systems
Grundfos non-code diaphragm tanks for Hydro Multi booster systems

Grundfos Diaphragm Tank for Hydro Multi-E and Multi-B Booster Systems - Non-Code

Size - Fits: 4.4 Gal - CRE 3, CRE 5, CME 3, CME 5

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$214.25
SKU: 91121888
Weight : 10.0 lb
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Description
Grundfos · Booster Accessory
Diaphragm Tank for Hydro Multi Booster Systems
The Grundfos-listed non-code diaphragm tank for each Hydro Multi-E and Hydro Multi-B pump size, 4.4 to 44 gallons.
4.4 to 44 Gal
Non-Code
Precharge 0.7 x Setpoint
Hydro Multi-E
Hydro Multi-B
Overview

Grundfos ships Hydro Multi-E and Hydro Multi-B booster systems without a tank and lists one diaphragm tank per pump size. The tank holds a small volume of water under pressure so the system can ride through low demand without restarting a pump for every draw; Grundfos recommends fitting one sized to the application to accommodate operation at low flow.

Grundfos states each size as the recommended minimum for the pump it is listed against. A larger tank is not wrong; a smaller one is.

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

Covered for 12 months from the date of purchase.

Models and Ratings
Part No. Volume Listed for Rating
91121888 4.4 gal Hydro Multi-E CRE 3 and CRE 5; Hydro Multi-B CME 3 and CME 5 Non-code
91121890 10.3 gal Hydro Multi-E CRE 10; Hydro Multi-B CME 10 and CME 15 Non-code
91121893 34 gal Hydro Multi-E CRE 15; Hydro Multi-B CME 15 and CME 25 Non-code
91121894 44 gal Hydro Multi-E CRE 20 Non-code

Sizes and pairings from the Grundfos price list effective January 1, 2026 (Hydro Multi-E and Hydro Multi-B pages); Grundfos lists both the 10.3 and 34 gal tanks for CME 15. Tank size is the recommended minimum.

Setting Up the Tank
Precharge 0.7 times the system setpoint
Measuring precharge Measure in a pressureless system
Refilling Grundfos recommends refilling with nitrogen

Source: Hydro Multi-E Data Booklet 99347082, printed page 13.

Before You OrderMatch the tank to the pump size in your system from the table above. Grundfos does not publish the tank connection size or maximum pressure in its price list, so ask us to confirm both against your system pressure before ordering.
For engineering-led sizing and selection support or a factory submittal, email sales@watermainsupply.com or call 1-888.510.4036.
© Watermain Supply — A division of E4 Industrial LLC
Data Sheet
Hydro Multi-E Data Booklet, US 60 Hz (99347082, 10.2025)
Videos

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