Storage tanks operate through 2 primary pressure systems: atmospheric tanks at ambient pressure and pressurized tanks containing compressed air systems. Industrial water applications require specific storage tank configurations based on pressure requirements, flow demands, and distribution needs.
Water treatment facilities utilize atmospheric storage tanks for bulk liquid storage at 14.7 psi ambient pressure and pressurized storage tanks for on-demand distribution at 7-60+ psi operating pressures. Selection criteria include capacity requirements from 15-1,000+ gallons, distribution pressure specifications, and installation constraints. Both tank types serve critical functions in residential, commercial, and industrial water distribution systems through distinct operational mechanisms and application parameters.
What Are Atmospheric Storage Tanks?
Atmospheric storage tanks operate at ambient atmospheric pressure (14.7 psi) and rely on gravity for water distribution through vertical positioning. These Atmospheric storage tanks contain liquid at standard environmental pressure conditions without pressurized air systems.
Atmospheric tanks function through gravity-fed distribution mechanics where vertical tank height creates water pressure at approximately 0.433 psi per foot of elevation. High-density polyethylene (HDPE) construction provides chemical resistance, UV stability, and impact protection for outdoor installations. Translucent tank materials enable visual monitoring of liquid levels through exterior walls.
Capacity specifications range from 15-gallon residential units to 1,000+ gallon industrial installations. Applications include food processing, agricultural irrigation, rainwater collection, and chemical storage facilities requiring FDA-compliant materials.
| Tank Size | Diameter | Height | Outlet Size |
|---|---|---|---|
| 100 gal | 28" | 43" | 1.5" FNPT |
| 500 gal | 48" | 73" | 2" FNPT |
| 1000 gal | 73" | 68" | 2" FNPT |
Tank configurations include vented manway access ports for cleaning and maintenance operations. Installation requirements specify flat, level foundations to prevent structural stress and ensure proper drainage functionality.
What Are Pressurized Water Storage Tanks?
Pressurized water storage tanks maintain 7-60 psi internal pressure through bladder or diaphragm systems that compress air to force water through distribution lines. These Pressurized Storage Tanks utilize internal bladder configurations that separate water from compressed air chambers.
Compressed air pressure delivery mechanics create consistent water flow without requiring pumps during discharge cycles. Metal tanks feature coated steel construction with virgin polypropylene liners and chlorobutyl diaphragms. Fiberglass reinforced plastic (FRP) tanks provide seamless composite construction with butyl aircell technology for residential and commercial installations.
Pressure specifications range from 7 psi residential systems to 60+ psi commercial applications. Key components include bladder membranes, diaphragm assemblies, pressure switches, and brass air valves with sealed caps. Draw down capacity represents usable water volume between cut-in and cut-out pressure settings.
| Tank Type | Capacity | Pressure Range | Draw Down |
|---|---|---|---|
| PAE Metal | 4-20 gal | 7-28 psi | 0.4-5.9 gal |
| ROmate FRP | 20-120 gal | 7-60 psi | 13-84 gal |
Installation requires 7 psi pre-charge maintenance and NSF-58 certification for potable water applications. Tank sanitization occurs during filter changes to prevent bacterial contamination.
Atmospheric Storage Tanks vs. Pressurized Storage Tanks
5 critical differences distinguish atmospheric and pressurized storage tanks: pressure operation, distribution method, installation requirements, capacity ranges, and maintenance protocols.
Pressure Operation: Atmospheric tanks operate at 0 psi ambient pressure without internal compression systems. Pressurized tanks maintain 7-60+ psi compressed air systems through bladder technology for consistent water delivery.
Distribution Method: Atmospheric tanks utilize gravity-fed flow requiring elevated positioning above distribution points. Pressurized tanks provide pressurized delivery to multiple outlets through compressed air pressure mechanics.
Installation Requirements: Atmospheric systems require elevated positioning with gravity feed lines and structural mounting support. Pressurized systems allow ground-level installation with pressure monitoring equipment and shut-off valve connections.
Capacity Applications: Atmospheric tanks range 15-1,000+ gallons for bulk storage applications including irrigation and fire protection. Pressurized tanks span 4-120 gallons for on-demand residential and commercial systems.
Maintenance Protocols: Atmospheric tanks require periodic cleaning and outlet inspection for sediment buildup. Pressurized tanks need pressure testing, bladder replacement cycles, and air valve service for optimal performance.
Cost Considerations: Atmospheric systems offer lower initial cost with minimal operating expenses for basic storage needs. Pressurized systems involve higher equipment cost with ongoing pressure maintenance requirements but eliminate pump systems.
Material construction spans high-density polyethylene for atmospheric tanks and steel/fiberglass for pressurized vessels with FDA compliance standards.
Which Storage Tank Distribution System Works Best?
3 application factors determine optimal storage tank selection: water demand patterns, distribution pressure requirements, and installation constraints.
Choose Atmospheric Vertical Storage Tanks When: Bulk water storage exceeding 500 gallons suits gravity-fed distribution systems and agricultural irrigation applications. These tanks comply with USDA/FDA standards for food processing requirements while offering cost-sensitive installations.
Choose Pressurized Water Storage Tanks When: On-demand water delivery requires multiple outlet distribution points through residential reverse osmosis systems. Commercial applications demand consistent pressure delivery in space-constrained installations.
Technical Application Examples: Atmospheric 1000-gallon tanks handle industrial process water storage with 73-inch diameter capacity. Pressurized 20-gallon tanks provide residential RO water delivery through 1-inch MPT connections. Atmospheric 500-gallon systems support agricultural chemical mixing with 2-inch FNPT outlets. Pressurized 80-gallon units serve commercial food service applications with butyl aircell construction.
Installation Considerations: Atmospheric tanks require minimum 8-foot elevation for adequate pressure distribution through gravity flow mechanics. Pressurized systems need electrical connections for pressure switches maintaining 7-60 psi operating ranges. Both systems require proper foundation support and freeze protection through insulation materials.
High-density polyethylene atmospheric tanks span 15-1,000 gallon capacities. Steel/fiberglass pressurized vessels range 4-120 gallons with NSF-58 certification standards ensuring water quality compliance.
Conclusion
Storage tank selection between atmospheric and pressurized systems depends on application requirements, pressure needs, and capacity demands. Atmospheric tanks excel in bulk storage applications exceeding 500 gallons while pressurized systems provide on-demand distribution for residential and commercial installations. Both tank types serve critical roles in water treatment systems when properly sized according to technical specifications and USDA/FDA standards. Proper system design ensures optimal performance and compliance with industrial water storage requirements. AXEON Supply provides comprehensive storage solutions supporting diverse water filtration applications across residential, commercial, and industrial markets.