12 Units 80m3 LPG Storage Tanks Are Ready for Delivery

Recently, 12 units of 80,000 litre LPG storage tanks finished production and testing at our Suizhou works and are now waiting for transport. The tanks were built to one specification on one order: ground mounted pressure vessels with a water capacity of 80 cubic metres each, designed to hold liquefied petroleum gas at a working pressure of 17.7 bar.

Eighty cubic metres sounds abstract until you convert it. Propane is filled by mass ratio, 0.42 kg per litre of water capacity, so each tank legally carries about 33.6 tonnes of LPG. Twelve of them together hold more than 400 tonnes, which is not a fuel dump. That is a filling plant.

Key specifications

What went into the build

Plate, thicker where the stress goes

The shell is 16 mm Q345R and the heads are 18 mm. The heads take the extra 2 mm because that is where forming stress concentrates, so the difference is not a rounding error. Q345R is the workhorse steel for pressure vessels in China, and it was chosen here for the same reason it is chosen everywhere: it holds its strength across the whole working temperature range of the tank.

Tested a quarter above its working pressure

Every tank was hydrostatically tested at 22.2 bar, about 25% above the 17.7 bar working pressure, and held. Welds are radiographed before the pressure test, not after it. A tank that passes pressure while hiding a slag inclusion in a seam will not stay passed for 20 years.

The fittings that make it a plant, not a shed

A 450 mm manhole on top for internal inspection. Rochester level gauge, pressure gauge, thermometer, safety valve and an emergency shut off valve. Around the outside, a galvanized water spray pipe for emergency cooling, lifting lugs for placement, and an earthing copper strip so a transfer does not turn static electricity into a spark.

A coating sized for two decades outdoors

80 microns of zinc rich primer, then two epoxy coats adding another 140 microns, 220 microns in total. On a tank that stands in the open for 20 years, coating thickness decides whether you repaint in year 6 or in year 15.

How it differs from an ordinary fuel storage tank

That last row is why the paperwork matters more than the price. A fuel tank built to a wrong specification leaks slowly. A pressure vessel built to a wrong specification does not get the chance to leak slowly.

Where these tanks go

1. Cylinder filling plants, where 80 cubic metres is enough inventory to keep a medium filling line running between road tanker deliveries.

1. Autogas stations, as motor fuel storage feeding the dispensers.

1. Industrial users such as ceramics kilns, glass furnaces, metal cutting and crop drying, wherever a process burns propane by the tonne.

1. Regional depots that tranship between coastal import terminals and inland markets.

Precautions before and during use

Commission with nitrogen. Purge the tank with dry nitrogen and keep the oxygen content under 3% before the first LPG goes in. Air mixed with propane vapour is the one mixture nobody wants inside a vessel.

Respect the filling ratio. The tank is rated at 0.42 kg per litre of water capacity. Liquid propane flashes to vapour at roughly 300 to 1 by volume, and a tank filled to the top on a cool morning becomes an overfilled tank on a hot afternoon.

Put the safety fittings on a calendar. The safety valve, pressure gauge and thermometer all carry inspection dates. Write those dates into the maintenance plan at commissioning rather than waiting for the first annual inspection to remind you.

Use the earth strip. Connect the earthing copper strip before any liquid transfer, every time, without exceptions.

Keep water behind the spray pipe. The galvanized deluge ring only helps if the pump and the water supply behind it are maintained, so test the spray system on the same schedule as the safety valves.

Closing

Twelve tanks, one specification, and a full set of test records for each unit. Chusheng holds the special equipment design and manufacturing licences in its own name, so the design, the welding and the hydrostatic test all happen inside our own works in Suizhou. If you are planning an LPG storage project, send us the capacity you need and the ambient temperature range at your site. We quote FOB, CIF or CFR, and we will tell you honestly when a budget and a pressure rating do not match.