Technical specifications of ball valve

Leakage class - determines the maximum allowable leakage through the closed ball valve with atmospheric pressure on one side and water pressure of 1.1*PN on the other side. The water temperature during testing should be in the range of 5 to 40°C.

• Class A - no leakage
• Class B - no more than 0.0006*DN(mm) cm³/min
• Class C - no more than 0.0018*DN(mm) cm³/min
• Class D - no more than 0.006*DN(mm) cm³/min

Most ball valves have leakage class A.

DN - nominal diameter - is used to indicate the size of piping components, has no dimension, and the numerical value of DN approximately equals the internal diameter of the connected pipeline in millimeters. The nominal diameter is applied to all elements of piping systems except pipes and components characterized by an external diameter.

PN - nominal pressure - is the maximum excess pressure of the working medium at a temperature of 20°C, at which continuous operation of the ball valve is allowed.

Test pressure - is the excess pressure used to conduct hydraulic testing for strength and tightness with water at a temperature of 5 to 70°C, unless a different test temperature is specified in the ball valve documentation or regulatory documents.

Working pressure - is the maximum excess pressure at which the specified operating mode of the shut-off valve is ensured, taking into account the temperature of the working medium. The working pressure value is usually lower than the nominal pressure value, so simultaneous operation at the maximum working temperature and nominal pressure is not allowed.

Kvs - flow coefficient - is numerically equal to the water flow rate in m³/h at a temperature of 20°C, with a pressure loss on the valve of 1 bar. The flow coefficient is used in hydraulic calculations to determine pressure losses in the elements of piping systems.

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