Grundfos GNTA ASME diaphragm expansion tank, representative drawing
Grundfos GNTA ASME diaphragm expansion tank, representative drawing

Grundfos GNTA ASME Diaphragm Expansion Tank - Hydronic

Max Pressure: 150 PSI
Capacity: 7.8 Gal
Model: GNTA-15

Product variant with selected options does not exist!
$803.72
SKU: 99426692
Weight : 42.0 lb
Loading locations...
Free Shipping $499 or more
Skip the chatbot. Talk to an expert.
1-888.510.4036 · Same-day shipping available
Description
Grundfos · ASME Hydronic Expansion Tank
GNTA Diaphragm Expansion Tank
12 sizes from 7.8 to 158 gallons for closed heating and cooling loops.
150 PSI (GNTA-15 to 60), 125 PSI Larger
ASME Section VIII Div. 1
Fixed Heavy-Duty Butyl Diaphragm
Partial Acceptance
7.8-158 Gallons
Up to 240°F
Closed Hydronic Heating and Cooling
Overview

Grundfos GNTA tanks are ASME diaphragm expansion tanks for closed hydronic heating and chilled water systems. As the system heats up, the water expands into the tank against an air cushion held behind a heavy-duty butyl diaphragm, keeping system pressure steady and below the relief valve setting. The diaphragm is fixed (not replaceable) and the tank is partial acceptance: the acceptance volume in the table is the most system water the tank can take.

The tank is factory pre-charged and field adjustable; set the pre-charge to the system fill pressure at the tank before filling.

What Ships and What It Needs to Run

Included: the GNTA tank with factory-installed diaphragm and charging valve.

Ships: about 42-591 lb by model, by LTL freight to a commercial dock; liftgate or residential delivery is a paid checkout option. Larger tanks ship on their own skid or base ring.

Needed to install: isolation valve and drain at the system connection, a pressure gauge or tire gauge to set the pre-charge, and a level floor or pad rated for the full-of-water weight.

Genuine Grundfos equipment, factory-new in original packaging — sold and supported by Watermain Supply, an independent industrial supplier.
Specifications
Tank type Fixed diaphragm, partial acceptance
Code ASME Section VIII Division 1
Max working pressure 150 PSI (GNTA-15 to GNTA-60), 125 PSI (all larger)
Max temperature 240°F
Pre-charge Factory set, field adjustable
Models, Part Numbers and Weights
Model Part no. Gallons Acceptance (gal) Dia. x height (in) System conn. Max pressure Weight (lb)
GNTA-15 99426692 7.8 6.3 12 x 19 3/4 in 150 PSI 42
GNTA-20 99426697 11 8.8 12 x 25 3/4 in 150 PSI 52
GNTA-40 99426701 25 20 16 x 33 1 in 150 PSI 84
GNTA-60 99426709 35 28 16 x 44 1 in 150 PSI 97
GNTA-80 99426725 45 36 20 x 38 1 in 125 PSI 148
GNTA-100 99426727 60 48 20 x 49 1 in 125 PSI 175
GNTA-120 99426704 70 56 24 x 46 1-1/2 in 125 PSI 259
GNTA-144 99426707 80 65 24 x 49 1-1/2 in 125 PSI 268
GNTA-180 99426772 90 73 24 x 52 1-1/2 in 125 PSI 283
GNTA-200 99426784 115 93 24 x 66 1-1/2 in 125 PSI 325
GNTA-240 99426788 140 114 24 x 78 1-1/2 in 125 PSI 362
GNTA-260 99426790 158 128 30 x 63 1-1/2 in 125 PSI 591

Weights are Grundfos’s published figures (approximate shipping weight). Dimensions in inches. Tanks over 150 lb ship by LTL freight.

Before You Buy — The Limits That Decide the Fit
Service Closed hydronic systems only. Not for potable water: use GTXA for domestic hot water.
Sizing Choose by acceptance volume, not tank volume. Acceptance must cover the system’s expansion from fill to maximum operating temperature.
Liquid Water or water-glycol.
Pressure Relief valve at or below the tank rating.
Applications

Boiler and chilled water loops, radiant heating, heat pump and process cooling loops in commercial and institutional buildings.

Materials of Construction
Shell Steel
Diaphragm Heavy-duty butyl, fixed
Exterior Primer, black painted
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
Videos

Product videos are being added to this listing. For a walkthrough in the meantime, email sales@watermainsupply.com.

Share E-mail

You May Also Like