Cryogenic Liquid Storage Tank for LOX, LIN, LAR and LNG

How a Cryogenic Tank Keeps Cold for Months

Two vessels, one inside the other. The inner tank holds the liquid; the outer shell carries the vacuum. Between them sits perlite - expanded volcanic glass - and the annulus is pumped down to high vacuum. Heat can't ride convection through a vacuum, radiation gets intercepted by the multilayer shim, and what's left conducting through support struts and nozzles is what your daily evaporation number is made of: 0.4% a day on a 5 m³ unit, down to 0.23% on a 100 m³ giant. Top that up against your draw-off schedule and a tank can sit unattended for weeks.

Everything Inside the Skid: Nine Systems

A CFL tank is not a vessel with gauges bolted on; it's a mini plant:

1. Liquid filling system
2. Side-fill / topping system
3. Discharge system (pressurized withdrawal)
4. Safety relief - dual rupture disks and relief valves, redundancy by code
5. Vent system with regulators
6. Pressurization system (self-pressurizing via vaporizer coil)
7. Liquid level and pressure measurement
8. Vacuum system - vacuum port for lifetime re-evacuation
9. Spray system for flammable and explosive media (LNG/ethylene spec)

CFL Technical Parameters

Materials and codes

Inner vessel in S30408 austenitic stainless (16MnR for CO₂ duty), outer in Q345R structural steel. Welds get radiographic review under our A1 pressure-vessel manufacturing license; A2 covers the design. Every tank leaves with a full documentation package for your jurisdiction's registration - we've handed sets over on sites in 20+ countries.

Where CFL Tanks Live

Industrial gas supply. Behind every small ASU or VPSA plant we ship, usually several of them, buffering production from truck schedules. LNG filling stations, gasification and storage-distribution stations, peaker stations. The same vacuum-jacketed anatomy serves methane duty with the spray system fitted. Hospital oxygen banks, food and beverage CO₂ fields, laser-cutting shops that want a liquid buffer instead of a cylinder cage.

Installation Notes Most Suppliers Skip

These tanks sit on concrete pads with insulation underneath - ground heat is a real leak path. Orientation is vertical by default; relief discharge routing, oxygen exclusion zones and vaporizer sizing all come in our foundation and P&ID package rather than being improvised by your fitter. First fill is a warm-down conversation we're happy to supervise remotely.

FAQ

Reading A Tank Datasheet Like An Owner, Not A Brochure

Cryogenic tanks look interchangeable until the first month of liquid losses tells you otherwise. Four numbers on the datasheet deserve interrogation before price is ever discussed:

• Static evaporation rate (NER). Our published figures run 0.23-0.4% per day across the CFL range - but insist on the rate for your medium and your fill fraction, not the marketing minimum. A 0.1-point difference on a 100 m³ LNG tank is real money per year; on a small LIN tank it is rounding. Ask for the NER formula and the test basis.
• Annulus vacuum quality. The insulation only works while the annulus holds vacuum. Our tanks ship with a vacuum gauge port and a bake-out record; high-vacuum multilayer units come with argon-ion getter provision. If a supplier cannot show you the vacuum documentation, you are buying a thermos and a hope.
• Inner vessel material and weld documentation. S30408 austenitic stainless inner vessels for every cryogenic service we sell, with A1/A2 licensed weld records. Q345R carries the outer shell because it never sees the product. Anything cheaper is a code conversation you do not want to have in front of your insurer.
• The valve stack. Safety valves, rupture disc, vacuum breaker, fill and drain with super-cold-rated trim. Tanks die from blocked outlets, not from punctures - never let anyone swap your valve schedule to save two hundred dollars.

The Nine Systems That Make It A Plant Component

A storage tank in a working gas site is a system, and the CFL line ships with all nine subsystems piped, tested and documented:

• Liquid fill system with differential-pressure-controlled filling so the inner vessel never thermal-shocks.
• Drain and transfer through the cryogenic pump or pressure-build loop, sized for your tanker-fill or process-feed rate.
• Pressurization system - the small vaporizer loop that builds tank pressure for transfer without a compressor.
• Safety relief - main and auxiliary relief paths sized for the worst credible heat case, per code.
• Level measurement - differential-pressure plus guided-wave options; your DSO operator reads the same number the PLC trusts.
• Pressure instrumentation with cryogenic snubbers so gauge siphons do not freeze mid-read.
• Vacuum maintenance port for re-evacuation campaigns - the system that quietly doubles tank life.
• Strategic spray system for safety relief management in larger installations.
• Foundation and seismic details per your site code; our civil drawings come conditioned to your soil report.

Sizing, Siting, And The Cold-Start Reality

Tank volume is sized against three habits: your peak transfer rate (a tanker or a filling station sets the tempo), your resupply interval (a plant that gets one liquid delivery a week lives in a bigger tank than a daily-resupply site), and standby duty (hospitals and gas companies pay for reserve volume they only touch on emergency weeks).

Commissioning a cryogenic tank is one word: cool-down. Ambient steel cracking open to -196 °C liquid is a fatigue story; our procedure cools in staged lifts with the fill-control loop doing the work. First cool-down of a warm tank takes hours to days depending on volume, and never let a contractor "save time" by pouring liquid onto warm walls.

Shipped as standard horizontal road-transportable units up to our transport-limited sizes, vertical footprint-minimized units for tight sites, and everything in between; rail and barge arrangements quoted for the 50 m³-plus class. Your tank arrives with pressure-vessel certification, the vacuum bake record, and the nine systems wet-tested before the desiccant bags go in.

Ordering A Cryogenic Tank: What We Need From You

A CFL quotation is built from seven inputs, and any buyer who supplies all seven gets an accurate price in one round instead of five:

• Medium and service - LOX, LIN, LAR, LCO₂, LNG or ethylene; each has its own valve trim, code route and safety story.
• Design pressure from your transfer method - pump transfer wants less tank pressure, self-pressurized transfer wants more.
• Volume, sized against resupply interval and standby duty as described above.
• Orientation and site envelope - horizontal runs cheap and road-transportable; vertical buys back floor space.
• Foundation and seismic data - our civil drawings get conditioned to your soil report, not a generic pad.
• Documentation set for your jurisdiction - A1/A2 vessel records travel with the tank; some markets want additional third-party inspection, which we arrange and price honestly.
• Accessories ambition - standard gauge package versus digital level and remote pressure transmission tied to your control room.

Tanks ship internationally as standard road freight within our transport-limited sizes; the 50 m³-plus class goes by barge or rail rig with route surveys we specify. Every tank that leaves Kaifeng carries its pressure-vessel dossier, vacuum bake-out record and the wet-tested valve stack - which is precisely the paperwork your insurer, your safety officer and your next inspection will ask to see.