Preferred Construction Products

HVAC Expansion Tanks

Closed Loop • Non-Potable • Hydronic Heating & Cooling • Heat Transfer

Used to absorb the additional volume of potable water created by a domestic water heater. These tank designs incorporate a diaphragm or bladder to isolate the expanded water from the pressure controlling air cushion.


  • Pre-charged (12PSIG)
  • Carbon steel shell and heavy duty butyl (FDA approved) bladder or diaphragm
  • N, NL, NTA, NLA, NLAP, NVA 240°F Max Temp; NA, NAG 450°F Max Temp
  • NTA, NLA, and NLAP series can be installed vertically or horizontally

HVAC Expansion Tanks

ModelDescriptionASMEGallonsMax Pressure
N-SeriesFixed Diaphragmnon-ASME2.1-79.4150 PSIG
NL-SeriesRemovable Bladdernon-ASME2.1-132.1150 PSIG
NTA-SeriesFixed DiaphragmASME7.8-211150 PSIG
NLA-SeriesRemovable BladderASME10-3963125 PSIG
NLAP-SeriesTop System Connection Replaceable BladderASME11-290125 PSIG
NVA-SeriesBottom System Connection Removable BladderASME15-525125 PSIG
NLA-HP-SeriesHigh Pressure Removable BladderASME10-3963200/250 PSIG
NA-SeriesPlain Carbon Steel CompressionASME15-525varies 125/150 PSIG
NAG-SeriesGalvanized Carbon Steel CompressionASME15-525varies 125/150 PSIG