Pressurized Tanks

Pressurized tank consists of an inner pressure vessel, outer vessel, insulation and one or two necks with the valves, flanges or unions. The valves are used for filling and dispensing the cryogenic liquid, and a pressure-control valve with a brittle rupture-disk for backup protection.

A pressurized tank stays outside the cryosauna. It is connected with a hose which should be  provided by your nitrogen supplier (if not, you can buy a 2-meter hose from us). Nitrogen flow is regulated by a cryogenic valve which opens at regular intervals when a session starts, with pressure pushing nitrogen through the hose into the cryosauna. The pressure in the tank should be between 1.5 and 2.5 bar. 

There are some signs that could indicate that a pressure tank is bad and not suitable for use:

• the tank has visible signs of damage or modifications;
• there is no date stamp or code that inspection was carried out or it is overdue (inspection period of usually 5 years);
• there is no identification and rating label along with the manufacturer’s name and or logo and that it is suitable for the gas type.
• It does not comply with the local standards for pressure regulators and gauges are not marked to comply with the appropriate local standards;
• the tank connection is dirty with oils, greases, solvents or debris and it is not perpendicular to the regulator body.
• the pressure rating is not suitable for the cylinder pressure;
• the pressure relief valves are damaged and modified.

In order to avoid any problems with pressurized tanks, choose a trusted supplier and follow all safety rules when using it.

Talking about pressurized tanks for nitrogen storage, there are two types of tanks depending on pressure: low pressure tanks and high pressure tanks.

Low pressure tanks have a working pressure range of 1.5 bar and in some cases up to 4 bar for the withdrawal of liquid nitrogen. Usually these stainless steel vessels are movable with rotating casters, but in some cases it can be a stainless steel transport cart with air tyres or pallet frame. Optionally, these pressure tanks can come with a pressure building device and/or capacitive probe for level measurement.

High pressure tanks have a working pressure range of 4 bar and in some cases up to 37 bar for the withdrawal of gaseous nitrogen. Often these tanks are with larger volumes starting from 180-230 liters and going up to 600-1000 liters and more.

We provide only pressurized tanks with a pressure-building system, which ensures maximum operating pressure of 4 bar.

Pressurized tanks are portable, safe, and convenient storage of high volumes of liquid nitrogen. All tanks are equipped with a pressure-building system, which ensures maximum operating pressure of 4 bar. There are regulators that don’t allow pressure to rise, but what about losing pressure?

If your pressure tank starts to lose pressure, that means that the conditions of transportation or storage have been violated and there is a leak of the gas. To avoid this, you need to comply with the rules for the storage of pressurized tanks:

• always read the container label prior to use;
• pressure tanks must always be stored in the upright position;
• pressurized tanks should only be moved with proper handling equipment;
• prior to use, ensure the fittings on the regulator match the fittings on the liquid container;
• never use adaptors;
• never attempt to change or remove any fittings.
• don’t try to modify a pressurized tank by yourself.

These rules will help you to prevent any problems with pressure tanks while using.

Purchase cryogenic pressure tanks only from trusted manufacturers. In case of any problems, contact your seller. Don’t try to solve the problem by yourself, it could be dangerous!

A big advantage of pressurized tanks is that the nitrogen will stay in them for years, they hold proper pressure and volume, regardless of time. It will always be ready to go in an instant (if the valves work). However, the pressurized tank owner (if you rent it) usually charges a rental fee for the tank, and that can be expensive over time. If you have a possibility, it is better to purchase a pressurized tank and refill it when needed. 

Pressure tanks should be tested every 5 years and they are date stamped for the last test. Refilling stations may not refill if the test period is beyond the nominal test date.

When you buy a new pressurized tank, it is essential that the three safety inspections listed below are carried out:

1. Color coding and labels. Although cylinders are color coded, this should not be relied upon to identify the contents. The label affixed to the cylinder must always be used as the primary means of contents identification. Cylinders without labels or where the label doesn’t match the color coding should not be used. Contact your supplier on that issue.

Having determined the contents of the cylinder, it is then necessary to check that the gas is suitable for the application. The pressure of the gas in the cylinder should not be greater than the regulator fitted.

2. Tank valve. The tank valve comes fitted to the cylinder when it is delivered. It is basically an open or closed valve operated with a key/spanner. The pressure regulator is then fitted to this. If the valve is on a newly filled, unused cylinder it should have a factory sealing cap in place. Checks should be carried out to ensure the fitting is undamaged and contaminate free. 

3. Check the pressure regulator:

• should be the date stamp or code (the inspection period of usually 5 years);
• make sure that the identification and rating label is in place along with the manufacturer’s name and logo;
• If it complies to local standards for pressure regulators and gauges are marked to comply with the appropriate local standards;
• If there are any signs of damage or modifications.
• if the regulator gauges are in place and of the correct type for the gas and scales suitable for the gas pressures. 

In case you suspect that something is wrong with your tank, it is best to call in specialists for a thorough check.

The place where the pressure tank is going to be located, should confirm several requirements:

• it should be well-ventilated;
• the pressure tank should be at a safe distance from combustible materials, ignition sources, or intense heat;
• the pressurized tank must be kept away from electrical circuits, open flames, sparks, etc. because it is metal and conducts electricity;
• the temperature in this place must not exceed +52°C. The gas expands when heated and increases pressure in the tank, increasing the risk of explosion;
• there should be no direct sunlight for the reason mentioned above;
• tanks should be stored away from heavily traveled areas and emergency exits;

Summarizing, nitrogen pressurized tanks should be stored upright in a well-ventilated, dry, cool, secure area that is protected from the weather and preferably fire-resistant. 

A liquid nitrogen in a pressurized tank will stay for years if all the storage requirements are met. Tank holds proper pressure and volume, regardless of time. It will always be ready to go in an instant (if the valves work). 

To ensure that your pressure tank is ready to use and it works properly, it should be tested every 5 years.

There are some cases when your pressure tank should be removed: 

• It is empty (before they reach 30 bar);
• You suspect gas leaks;
• The tank has signs of damage or modification;
• If your pressure regulator is not working properly.

So if you suspect that something is wrong with your pressure tank, it should be replaced and checked by specialists. Remember that using a bad pressure tank could be dangerous for you and your clients.