For tanks TK-102 / TK-102Zs. (Tank hydrocarbons four atoms; C4 Monomer as usual) tank TK-501 / TK-501Zs. (Tank hydrocarbons four atoms; C4 Raffinate as usual) tank can withstand voltage, over-voltage 2.5-fold by checking with the water pressure and the pressure of 1.7 times the pressure of the gas when the tank there. Pressure increased to 3.85 kg / cm2 can be extended up to the control room and the staff will stop adding chemicals. By stopping the pump into the tank When the pressure of the tank up to the control at 4.0 kg / cm2 alarm from the control room. The pump will stop the flow of chemicals into the tank automatically to prevent pressure increase.