Cargo tank pressure/vacuum valve, also known as high speed relief valve or P/V valve, is a necessary control type relief system for current oil tankers and chemical tankers.
Our series DF-ISO high speed relief valve is a new generation of non-oscillation and non-impact product. It has the maximum safety for oil tankers and chemical tankers.
Standards：
DF-ISO pressure/vacuum valves (also known as high-speed relief valves) are designed, manufactured and tested according to the following standards and specifications.
1.IMO.MSC/Circ.677 Revised Standards of Designing, Testing andInstalling the Device that can Stop the Flame into the Liquid CargoTank;
2.ISO15364 Ships and Marine Technology-Pressure/Vacuum Valvefor Cargo Tank;
3.IMO.MSC/Circ1324;
Applications：
Refer to EN12874-2001 “Performance requirements, test methods and scope of use of flame arresters”.
The pressure vacuum valve is installed at the top of each compartment as the only outlet and inlet of air for oil tankers and chemical tankers. When the liquid cargo tank is loaded, the pressure valve automatically discharges the mixed gas in the tank vertically upward at a speed of more than 30m/s; when discharging, the vacuum valve automatically replenishes the air in the tank to save the liquid cargo tank from overpressure and loss of pressure. The pressure vacuum valve made according to the above standard can prevent flames from entering the cargo tank even in working condition.
The test of our cargo tank pressure/vacuum valve is carried out in the laboratory approved by the national authority, and we have passed the test of all the following items according to the above-mentioned standards, and obtained the approval of China Classification Society and some foreign classification societies.
1.Fire Resistant Test; 2.Re-burning Test; 3.Frozen Test; 4.Corro-sion Resistant Test; 5. Flowing Test.
Main Characteristics：
Series DF-ISO pressure vacuum valve DF50, DF65, DF80, DF100, DF125, DF150, DF200, DF250, due to the special design of the pressure valve valve, the valve will be fully opened only when the system pressure steadily reaches the set opening pressure. Under the normal loading rate, after the valve is opened, the system pressure in the pipeline and cabin will drop about 20%~50% and then it can work stably and maintain the outlet flow rate of 30m/s. During operation, it will not cause sudden increase or decrease of system pressure. The high-speed outlet valve will not crash or oscillate at the minimum to maximum flow rate allowed for loading. The series valves can also be fitted with a magnetic control mechanism to handle valve chattering during navigation, which minimizes vapor loss during navigation.
The series DF-ISO pressure vacuum valve has basically zero leakage at 80% of the set working pressure, and can be selected for loading goods requiring zero leakage, which is one of the few most advanced valves in the world.
The series valves can work normally under the environment of -20℃~+60℃, and they can work normally even after the ice is broken when the valve port is frozen。
