1m³ cryogenic liquid storage tank

| Product Overview

The Micro Tank is the heavy-duty evolution of the 1m³ platform. The tank itself is slightly taller: 1300×1300×2600 mm, with tare weights rising from 1068 kg (1.6MPa) to 1227 kg (3.4MPa). The critical difference is that the Micro Tank is not just a storage vessel—it is a complete functional station. Each unit ships with a 40 Nm³/h ambient-air cascade vaporizer and a 20 Nm³/h pressure-building circuit as standard equipment. The vaporizer is a finned aluminum heat exchanger that converts liquid cryogen to ambient-temperature gas using atmospheric heat alone—zero electrical power, zero moving parts. The pressure-building circuit is a small self-contained loop that draws liquid from the tank bottom, vaporizes it in a small PB coil, and returns the gas to the tank headspace to maintain delivery pressure as liquid is withdrawn. These two subsystems transform the Micro Tank from a passive storage container into an autonomous gas supply station: connect a downstream pressure regulator and flow meter, and the system delivers continuous gaseous product without external pumps, external heaters, or operator intervention.

The three pressure tiers across the Micro Tank 1m³—1.6 MPa, 2.5 MPa, and 3.4 MPa working pressure—correspond to different end-use pressure requirements. The 1.6 MPa tier is the general-purpose industrial grade (laser cutting, welding shield gas, laboratory central supply). The 2.5 MPa tier accommodates medium-pressure distribution networks where gas must travel through extended pipe runs with non-trivial line loss. The 3.4 MPa tier serves high-pressure applications such as LNG vehicle refueling buffer storage, high-pressure cylinder filling manifolds, and processes requiring elevated delivery pressure without a downstream compressor.

Safety architecture is dual-redundant on the inner vessel: a spring-loaded safety relief valve (set at approximately 106% of design pressure, specific to each pressure tier) provides the primary overpressure protection with automatic reseating capability, while a rupture disc (set at approximately 106–111% of safety valve set pressure) serves as the non-reclosing secondary defense. The outer jacket carries its own vacuum safety valve at 0.18 MPa—a low-pressure device that protects the jacket from positive pressure in the unlikely event of an inner-vessel leak into the annulus, while also serving as the vacuum pump-out port during initial evacuation and periodic vacuum maintenance.

Media compatibility spans the full industrial gas spectrum: LOX (liquid oxygen), LIN (liquid nitrogen), LAr (liquid argon), LCAR (liquid carbon dioxide, 2.5MPa tier), and LNG (liquefied natural gas, 3.4MPa tier for the Micro Tank). The inner vessel material—022Cr19Ni10 (S30408)—is the Chinese standard equivalent of AISI 304L, selected for its combination of deep-cryogenic toughness (Charpy V-notch > 27J at −196°C), weldability without post-weld heat treatment, and universal chemical compatibility with the target media. The S32168 (06Cr18Ni11Nb, a niobium-stabilized 304 equivalent) variant is offered for LNG service where the risk of sensitization from repeated thermal cycling is higher.

| Working Principle

A 1m³ cryogenic liquid storage tank is a double-walled, vacuum-insulated pressure vessel whose function is to store a cryogenic liquefied gas at its boiling point (typically −183°C for LOX, −196°C for LIN, −186°C for LAr, −162°C for LNG) and deliver it either as liquid (for transfer to another vessel) or as ambient-temperature gas (for process consumption).

Insulation and the Zero-Boil-Off Illusion:

The tank does not maintain temperature actively—there is no refrigeration system. Instead, it relies on passive super-insulation to minimize heat ingress from the ambient environment. The insulation system is a three-layer composite: (1) the annular vacuum space between the inner and outer vessels, evacuated to ~10⁻³ Pa or lower, eliminating convective and conductive gas-phase heat transfer; (2) multiple layers of reflective foil (typically aluminum-coated Mylar) wound around the inner vessel, reducing radiative heat transfer—each additional layer reflects ~95% of the incident thermal radiation; and (3) perlite powder (expanded volcanic glass) filling the remaining annulus volume, providing a microporous barrier that suppresses residual gas conduction and acts as a secondary radiation shield. The combined effective thermal conductivity of this composite is on the order of 1 × 10⁻⁴ W/m·K—roughly 10,000× lower than solid stainless steel.

Despite this insulation, heat ingress is never zero. For a 1m³ tank with a surface area of approximately 7–8 m² and a typical heat leak of 1–2 W/m² for vacuum-perlite insulation, the total heat ingress is 7–16 W continuous. For liquid nitrogen, this translates to a boil-off rate of approximately 0.5–1.0% of tank volume per day under static (no withdrawal) conditions. The boil-off gas accumulates in the headspace, raising the tank pressure. When the pressure reaches the pressure-building regulator set point (for tanks equipped with the PB circuit), or ultimately the safety valve set point, the excess pressure is vented.

The Gas Delivery Cycle — Micro Tank Variant:

The Micro Tank 1m³ operates as a complete liquid-to-gas conversion station through three interacting circuits:

 Liquid withdrawal circuit: When the downstream gas-use valve opens, the tank's headspace pressure forces liquid through the bottom liquid outlet, up the internal withdrawal tube, and into the ambient-air vaporizer. The vaporizer is an array of vertically oriented finned aluminum tubes connected in series—the liquid enters at the bottom, progressively warms and vaporizes as it rises, and exits at the top as ambient-temperature gas. The energy for this phase change comes entirely from natural convection of ambient air over the fins; no external heat source is involved. The 40 Nm³/h specification means the vaporizer is sized to deliver 40 normal cubic meters of gas per hour continuously under rated ambient conditions (typically 20°C, 60% RH).

Pressure-building circuit:  As liquid is with drawn, the tank pressure would drop if uncompensated—the headspace volume increases but the mass of gas in the headspace does not. The PB circuit counters this: a small bleed of liquid is drawn from the tank bottom, passed through the PB coil (a smaller finned heat exchanger, 20 Nm³/h), vaporized, and returned to the tank headspace as pressurized gas. A pressure-building regulator controls this loop, opening when headspace pressure falls below the set point and closing when pressure is restored. This maintains a stable delivery pressure throughout the entire withdrawal cycle, from full tank to near-empty.

Safety relief circuit:The inner vessel carries two overpressure protection devices in series-parallel logic. The spring-loaded safety valve (set at ~1.7/2.6/3.5 MPa per tier) is the primary—it opens on overpressure, vents until pressure falls to its 85%+ reseat point, and closes automatically. The rupture disc (set at ~1.92/2.9/4.0 MPa) is the secondary—a non-reclosing, frangible metal diaphragm that bursts at a specific differential pressure and provides a definitive, cannot-fail-to-open last-resort defense. The outer jacket carries its own vacuum safety valve at 0.18 MPa to protect against an inner-vessel leak into the annular space.

The Electronic Scale Advantage — Mini Tank Variant:

Traditional cryogenic tanks use differential-pressure (DP) level gauges: a high-pressure tap at the tank bottom, a low-pressure tap at the headspace, and a DP transmitter that converts the hydrostatic head ρ·g·h to a level reading. This works adequately when the liquid density ρ is known, but cryogenic liquid density varies with saturation pressure, temperature stratification, and media type—a 10% density error yields a 10% level error. The Mini Tank's electronic scale bypasses this: by measuring the total tank mass and subtracting the known tare weight (750 kg), the remaining liquid mass is known directly. For liquid nitrogen at 808 kg/m³ saturation density, a 1000L nominal tank containing 700 kg of liquid is at approximately 87% fill—and this number is trustworthy regardless of the liquid's thermodynamic state.

| Application Fields

Scientific Research & Laboratory

It provides a stable supply of liquid nitrogen and liquid argon to university laboratories and enterprise R&D centers, supporting low-temperature physics experiments, material characterization, and biological sample preservation.

Metal Processing & Welding

In cold assembly processes, it uses low-temperature shrinkage to assist in the installation of precision parts. It also provides protective gas for high-precision welding such as argon arc welding, ensuring welding quality and stability.

Small-Scale Food Processing

It supplies liquid nitrogen to small food factories and dessert shops for quick freezing of pastries, ice cream, and fresh ingredients, locking in the original flavor and nutritional value of food.

Emergency Medical Support

It can be used as a mobile oxygen supply device in remote areas and emergency rescue sites, providing timely oxygen support for medical treatment.

Electronics Manufacturing

It provides a low-temperature and oxygen-free environment for the production of electronic components and semiconductor chips, improving product yield and reliability.

| Operation & Safety Guidelines

Pre-use Inspection

Check the appearance of the tank for damage, confirm the vacuum degree of the interlayer is normal, and verify that the pressure gauge, safety valve, and other accessories are in good condition. Ensure the installation site is well-ventilated and away from flammable and explosive materials.

Liquid Filling Operation

Connect the cryogenic liquid filling hose to the tank filling port, and open the valve slowly to control the filling speed. Stop filling when the liquid level reaches the rated capacity, and close the filling valve tightly.

Gas Supply Operation

Adjust the self-pressurization valve to reach the required working pressure, and open the gas outlet valve to supply gas to the equipment. Monitor the pressure and liquid level changes in real time during operation.

Safety & Maintenance

Operators must be trained and qualified before operation, and wear professional cryogenic protective equipment. Regularly check the vacuum degree and replace the sealing parts. Conduct a pressure test every year to ensure safe operation.

| Production Process

Container Forming---Insulation System Installation---Accessory Assembly & Debugging---Final Testing & Delivery

1.The inner container is processed from S30408 stainless steel plates through cutting, bending, and welding. The outer shell is made of Q345R steel, and both containers are subject to flaw detection to ensure no welding defects.

2.Multi-layer insulation materials are wound around the inner container, and the inner and outer containers are assembled with support devices. The interlayer is evacuated using a high-vacuum pump to achieve the required insulation effect.

3.Install the charger, vaporizer, electronic scale, and pipeline system on the tank body. Conduct commissioning of the self-pressurization system and remote monitoring system to ensure all functions operate normally.

4.Carry out strict performance testing, including pressure resistance, vacuum tightness, and evaporation rate tests. After passing all tests, issue a qualification certificate and arrange packaging and delivery.

| FAQ

1. Why does the Micro Tank have both a safety valve and a rupture disc? Isn't one enough? 

A: The two devices address different failure modes. The safety valve is a reclosing device—it opens, vents excess pressure, and then closes. This works perfectly for thermal expansion events (sunlight heating the tank, pressure rising slowly). However, a safety valve can fail due to: spring fatigue, ice-locking of the seat at cryogenic temperatures, external mechanical damage, or sticking from corrosion/contamination after extended service. The rupture disc is a non-reclosing device—a metal diaphragm that bursts precisely at a set differential pressure. It cannot clog, has no moving parts to jam, and does not depend on spring force. But once burst, it stays open, venting the entire tank contents.

The dual configuration (safety valve + rupture disc) provides defense-in-depth: normal overpressure events are handled by the safety valve, which reseats and vents only what is necessary. If the safety valve fails, or if the pressure rise rate exceeds the safety valve's discharge capacity (e.g., fire impingement), the rupture disc serves as the non-failing ultimate protection. A burst disc indicator or pressure gauge between the safety valve and rupture disc is needed to detect whether the safety valve has leaked/opened—otherwise there is no way to know if the interspace pressure downstream of the safety valve has risen.

2. What does "standard vaporizer 40 Nm³/h" mean, and is it sufficient? 

A: 40 Nm³/h means the vaporizer can continuously deliver 40 normal cubic meters of gas per hour under rated ambient conditions (~20°C, moderate humidity). Converting to equivalent liquid consumption: 1 Nm³ of gaseous nitrogen ≈ 1.25 L of liquid nitrogen, so 40 Nm³/h ≈ 50 L/h liquid draw rate. For a 1 m³ (1000 L) tank, this represents approximately 20 hours of continuous gas supply at full load. For a typical small factory—several laser cutters or a welding station—40 Nm³/h is more than adequate. If sustained demand is higher, additional vaporizer modules can be added in parallel; the 1 m³ tank's liquid withdrawal rate is not the limiting factor (the bottom liquid valve port diameter easily supports flow rates far exceeding 50 L/h).

3. Mini or Micro: which 1m³ tank should I choose? 

A: Already have an external vaporizer / pressure builder and only need storage + low-pressure liquid withdrawal → Mini Tank (300+ kg lighter, 274 mm shorter, lower cost)

No existing gas supply infrastructure, need a turnkey liquid-to-gas conversion station → Micro Tank (complete vaporization + pressure-building circuit included)

Need electronic scale precision metering → Mini Tank (this configuration is not listed for Micro)

Need 3.4 MPa high pressure or LNG service → Micro Tank only

Installation door clearance < 2.4 m → Mini Tank (2326 mm passes through standard 2.4 m door opening)

4. How is the electronic scale better than a differential-pressure level gauge? 

A: A DP level gauge measures ΔP = ρ·g·h and solves for h. The problem is ρ—saturated cryogenic liquid density varies with tank pressure (higher saturation pressure = warmer liquid = lower density). For LIN between 0.1 MPa and 1.6 MPa saturation pressure, density drops from ~808 kg/m³ to ~700 kg/m³—a 13% shift. If the DP instrument was calibrated at 0.1 MPa using ρ = 808, it will under-read by approximately 13% after the tank is pressurized to 1.6 MPa. The electronic scale measures total mass, which is completely decoupled from density. The trade-off is cost—load cells + mounting structure are more expensive than a DP transmitter—and sensor drift requires periodic calibration (though modern digital load cells drift less than 0.1% per year).

5. Does a 1 m³ tank need a foundation? 

A: Yes. Even though the Mini Tank is only 750 kg empty, fully loaded with LOX (1140 kg/m³ × 1.0 m³ = 1140 kg) brings the total to approximately 1890 kg. This is distributed over a 1300×1300 mm (1.69 m²) footprint, producing a ground bearing pressure of approximately 11 kPa (0.11 kg/cm²)—well within the capacity of ordinary concrete flooring, but the tank must be level. The manufacturer typically recommends a minimum 150 mm thick reinforced concrete pad extending at least 500 mm beyond the tank base dimensions on all sides. The Micro Tank consists of five modules: the tank itself, vaporizer, pressure builder, piping, and valve manifold, so the pad must accommodate the entire skid layout, not just the tank base.

6. How long does the perlite vacuum last? Does it need re-evacuation?

A: When manufactured correctly, the vacuum retention life of a perlite-filled vacuum annulus is 15–20+ years. Vacuum degrades over time due to: (1) outgassing from annulus structural materials (primarily the perlite powder and metal surfaces), and (2) trace atmospheric ingress through micro-leaks. The manufacturer mitigates this by heating the annulus to 300°C+ and holding for several days during the evacuation process (high-temperature bake-out), which desorbs moisture and gases adsorbed in the perlite micropores that would otherwise slowly release over subsequent years. Vacuum quality is monitored via a vacuum gauge on the jacket safety valve port. If the vacuum degrades above ~10⁻¹ Pa, the boil-off rate—indicative of insulation performance degradation—will increase significantly. At that point, the annulus can be re-evacuated using a mobile vacuum pump cart connected to the jacket safety valve port—typically a 2–4 hour procedure that does not require emptying the inner vessel.

7. What are the real cost savings of a small tank (1 m³) versus cylinder-pack supply? 

A: Take a small laser cutting workshop consuming 300 Nm³/month of gaseous nitrogen (~10 Nm³/day) as an example.

Cylinder-pack approach: A standard 40 L, 15 MPa high-pressure cylinder contains approximately 6 Nm³ of usable gas when filled to 150 bar. Two cylinders are needed per day. Wholesale cylinder gas costs approximately 30–50 RMB per cylinder (varies by region). Daily cost: 60–100 RMB. Monthly: 1,800–3,000 RMB. Additional costs to factor in: cylinder delivery charges (~200–500 RMB per delivery; assuming weekly deliveries, approximately 1,000–2,000 RMB/month), manual handling labor, manifold rental, production downtime during cylinder changeovers, and reverse logistics for empty cylinder returns.

1 m³ Mini Tank approach: A single 1 m³ LIN fill contains approximately 800 L × 0.808 kg/L ÷ 1.25 Nm³/kg ≈ 517 Nm³ of usable gas. At 10 Nm³/day consumption, one fill lasts approximately 52 days. Liquid nitrogen wholesale price (tanker delivery) is approximately 0.8–1.5 RMB per Nm³-equivalent. Cost per 1 m³ fill: 517 × 1.0 ≈ 517 RMB. Add monthly depreciation amortization (assuming 3-year, 50,000 RMB capital cost: monthly amortization ~1,400 RMB). Total monthly cost: 517 + 1,400 = ~1,917 RMB. This is at or below the cylinder scheme's ~3,000 RMB/month—while eliminating virtually all cylinder-handling labor and completely removing cylinder-changeover downtime between refill cycles. For heavier users consuming 5+ cylinders per day, the 1 m³ tank savings become overwhelming.

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Need a compact and efficient cryogenic gas storage solution? Our 1m³ Cryogenic Tank is in stock with 1000 units available, supporting fast delivery and on-site installation guidance. Contact us now to get a detailed product manual and exclusive preferential price!