Nord stone

Bladder/Diaphragm Tank – Pressurized Utility Vessels

Bladder Diaphragm Tank

Introduction

Bladder and diaphragm tanks are ASME-certified pressurized vessels engineered to absorb fluid expansion, stabilize system pressure, and prevent water hammer in closed-loop systems. They are widely used in HVAC, hot water, chilled water, boiler circuits, chemical processes, and industrial utility systems.

At NORDSTONE., we manufacture high-performance bladder and diaphragm tanks built to ASME Section VIII Div.1, PED, and NB certification with superior durability, precision, and reliability.

What is a Bladder / Diaphragm Tank?

These tanks feature a flexible internal bladder or diaphragm that separates the air chamber from the process fluid. This ensures:

  • Absorption of thermal expansion
  • Stable system pressure
  • Protection from water hammer and cavitation
  • Prevention of air absorption into the system

Key components include:

  • Cylindrical or spherical pressure vessel
  • Internal elastomer bladder or diaphragm
  • Inlet/outlet connections
  • Air charging valve
  • Drain & vent connections
  • Optional manway for inspection

Technical Features

1) Design & Construction:
  • Design Codes: ASME Sec VIII Div.1 / PED / NB / API
  • Tank Types:
    • Hot water bladder/diaphragm tank
    • Chilled water bladder/diaphragm tank
    • Pressurized bladder/diaphragm tank
    • Vertical or horizontal tanks
    • Custom industrial tanks
  • Design Pressure: 4 to 20 bar (higher on request)
  • Design Temperature: 5°C to 120°C
  • Material Selection:
    • Carbon Steel: SA516 Gr.60/70, SA106 Gr.B
    • Stainless Steel: SS304/304L, SS316/316L
    • Duplex / Super Duplex SS
    • Nickel Alloys: Inconel, Hastelloy, Alloy 20
    • Internal lining/coating for corrosion resistance
  • Internal Components:
    • Removable bladder or diaphragm
    • Air chamber with pressure control
    • Drain, vent & pressure instrumentation ports
2) Capacity Range:

Tanks are available from 50 Litres to 50,000 Litres, with custom volume, pressure, and fluid compatibility options.

Typical Design Envelope

Parameter Range Remarks
Diameter 0.3 m – 2.5 m Customizable
Height 0.5 m – 5 m Depends on volume
Volume 50 L – 50,000 L Larger on request
3) Nozzle & Accessories:

Standard tank connections include:

  • • Inlet/outlet nozzles
  • • Air charging valve
  • • Safety relief valve connection
  • • Pressure gauge port
  • • Drain & vent nozzles
  • • Optional manway (large tanks)
4) Surface Finish:
  • • SA 2.5 grade sand/grit blasting
  • • Anti-corrosive primer coating
  • • PU/Epoxy final top coat (custom colors)
  • • Internal lining (if required)
  • • External insulation supports (optional)
Functional Advantages:
  • •

    Precision Pressure Regulation

    Bladder/diaphragm absorbs expansion and maintains stable pressure in closed-loop systems.

  • •

    Equipment Protection

    Prevents overpressure, water hammer, and cavitation in pumps, boilers, and pipelines.

  • •

    Extended System Reliability

    Ensures long-term performance with minimal maintenance.

Optional Packages:
  • •

    Configuration Options

    • ✔ Vertical or horizontal orientation
    • ✔ Removable bladder/diaphragm
    • ✔ Nitrogen pre-charging
  • • Insulation & custom coating packages
  • • Pressure, temperature & level instrumentation
  • • Third-party inspection (TUV / DNV / BV / SGS)
Quality Assurance:

All bladder/diaphragm tanks undergo strict testing:

  • • Hydrostatic & pneumatic testing
  • • Ultrasonic testing (UT)
  • • Magnetic particle & dye penetrant inspection
  • • Bladder/diaphragm integrity verification
  • • Material traceability — EN 10204 3.1 MTC
  • • ASME U-stamp & NB certification (optional)

Industries Served

  • • HVAC & Chilled Water Systems
  • • Hot Water & Boiler Systems
  • • Industrial & Utility Systems

Why Choose NORDSTONE.?

  • • 20+ years of experience in pressurized utility vessels
  • • Advanced thermal & mechanical simulation
  • • ASME-certified global fabrication
  • • Customized solutions for HVAC / CHW / hot water systems
  • • Complete QA/QC with third-party inspection support
  • • Proven reliability across industrial & commercial sectors
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Ready to Discuss Your Bladder/Diaphragm Tank Requirements?

Contact our engineering team for custom solutions and quotations.

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