In Refinery and Chemical plants explosive hazards occur if air enters tanks containing volatile flammable liquids during pumping operations. When liquid is removed from a tank or ambient temperature reduces, vacuum may be developed.

Hence, for optimum protection of tank, contents and the environment, a low positive constant gas pressure is maintained in the vapour space of a storage tank. A blanketing gas, nitrogen being the most popular, serves to reduce the oxygen content in the vapour space, making it inert and eliminating the possibility of combustion. This prevents the ingress of air and moisture from entering the storage vessel. When liquid is removed from a tank or ambient temperature reduces, vacuum may develop. Blanketing system prevents any vacuum from developing and maintains the desired blanket pressure. In addition to this, a blanket gas pressure, reduces the evaporation of the stored product to a negligible amount. The result not only conserves product but also greatly reduces emissions. Quality of chemical, which get affected by contact of moisture or oxygen is protected by blanketing. These advantages are in addition to the fire protection that is provided.

Hundreds of tanks blanketed successfully for years together. Our clientele includes well known leaders in the field of Refineries , Petrochemicals, Pharmaceuticals & Pesticides, Fertilizers & other process industries.
Some of the fluids blanketed are:-
Acetic Acid, Orthoxylene, Chloroxylene, Ethylene, Naphtha, NGL, Benzene, Hexane, Cyclo - Hexane, Toluene, Methanol, Ethanol, Xyelene, Styrene, Ethyl Acetate, Ethylene Dichloride (EDC), Ethylene Oxide, Carbon Sulfide, Aniline, Kerosene, Phynol, VCM, Mercaptan, Iso Propyl Alcohol (IPA), Acetonitrile, Acetone etc.

The complete station is required if nitrogen from high pressure cylinders (140 barg.) is used. The Nitrogen high pressure reducing station includes manifold system having provision for connecting number of cylinders. Each cylinder is connected through an isolating valve. Pigtails with proper adapters for connecting cylinder to the manifold are also supplied. The manifold is complete with pressure gauge assembly and low pressure alarm (optional).

The cylinder pressure of 2000 psig is reduced in two stages by PCV-1 and PCV-2 to the required header pressure (typically 2 to 5 barg.) Safety Valves SRV-1 and SRV-2 are connected at the outlets of PCV-1 and PCV-2 respectively to relieve excess pressure in case of contingency.
The Nitrogen header either from the high pressure reducing station or Nitrogen generation plant is taken on top of each tank.

Here the pressure is reduced to few inches of water column & supplied to the tank. These systems are available in either pilot- operated B3/-Series or self-operated DL-Series models. Each system offers distinct advantages.

This is pressure relief valve which does not allow pressure at its inlet to rise above a set value. Thus, this is used to protect the vessel from excess pressure during tank filling. Outlet of valve can be connected to the condenser for vapour recovery.

Breather Valve i.e. Pressure cum vacuum relief valves are the valves which not only relieve excess pressure in the tank but also breath in external air when pressure in the tank goes below atmospheric pressure.

If the chemical is drawn from the tank additional nitrogen pressure is fed to the tank by the blanketing regulator system. In case, if the nitrogen is not available from the source, then the tank may go under negative pressure and vacuum is created in the tank. Due to this the tank may collapse. To avoid such accidents vacuum relief valve breathes in atmospheric air and protects the tank from further damage.

These valves are used to provide an easy access to tank and to ensure a large emergency relief opening in case of exposure to fire.