Control ball valves
NPS DN 6”…28” Class 150…900
API 6D
NPS DN 6”…28” Class 150…900
API 6D
MAIN CHARACTERISTICS
Control Ball Valves are designed to control working medium parameters (pressure, flowrate) by throttling flow at pipelines.Working medium: natural gas, oil, oil products and other gaseous and liquid media at temperature from -15 °C to +250 °C.
Depending on their application the following ball valves can be manufactured:
RATINGS: #150-#300-#600-#900
Installation type: aboveground or underground.
Actuator type: electric actuators.
Connection to the pipeline: RF/RTJ (ASME 16.47, ASME 16.5) or BW (ASME 16.25)
Depending on their application the following ball valves can be manufactured:
- Control ball valves;
- Shut-off control ball valves.
RATINGS: #150-#300-#600-#900
Installation type: aboveground or underground.
Actuator type: electric actuators.
Connection to the pipeline: RF/RTJ (ASME 16.47, ASME 16.5) or BW (ASME 16.25)
MATERIAL SPECIFICATION
CAPACITY
DESIGN FEATURES
Control valve has all the advantages of ball valves as a standard: reliability; ergonomic design, ease of installation, stable tightness index of shut-down element, and suitability for different types of medium.
1. UNIQUE DESIGN OF CONTROL VALVE CLOSURE Control element of control valve (the ball) is designed to ensure a wide range
of control and high flowrate capacity with minimal pipeline pressure
reduction. Low resistance factor is achieved by parallel leveling of the inner
grids of the ball with working medium flow in the “open” position
minimizing obstruction surface at the way of the flow. This design has been
developed to allow smooth control of pressure drop while maintaining
anti-cavitation effect, which allows to reduce significantly the noise levels.
High flowrate is maintained due to the minimum resistance surface of the
obturator to the working medium. System of protection against impurities
inside the valve is provided by ball design: ball valve performs the function
of self-cleaning by the medium flow in the “open” position.
2. TRUNNION MOUNTED BALL
Control Valves are develope basis PTPA High Performance Trunnion
Mounted Ball Valves having the same design, features and high reliability.
3. SPLIT-BODY DESIGN
Split-body design increases valve maintainability, allows to use it at aggressive working medium and conduct:
- components replacement;
- maintenance without dismantling.
4. STEM DESIGN
Stem design allows replacing of the upper gasket while pipeline continues
its operation. Antistatic feature is provided in seals design.
5. METAL-TO-METAL SEAT DESIGN
CAVITATION-FREE OPERATION
Cavitation may appear during control valve operation. Cavitation is a process of vaporation and the following devaporation of air and gas bubbles in the liquid flow which are deteriorated coming to the area of high pressure. Cavitation may seriously damage hard surfaces and become the reason of loud noise. In order to solve this problem grid blocks are provided at the inner grids of the ball of PTPA shut-off control ball valves. These grid blocks divide medium flow and suppress cavitation effect.
Information concerning adjustable measure of valve cavitation in required technological conditions for all modes - KCS should be submitted to manufacturer for identification of possible cavitation in control valves. Adjustable measure of the beginning of valve cavitation - KC is identified by experiment or calculations while adjustment of a control ball valve.
The condition of cavitation-free operation of control valves is that cavitation measure does not exceed the factor of the appearing of cavitation in working conditions (for all modes): Kcs < Kc
Methods of identification of control ball valve hydraulic and cavitational characteristics are based on ST Central Design Bureau of Automatic equipment 029. Methods of calculation of ball valve hydraulic and cavitational characteristics ensuring cavitation-free operation is based on ST Central Design Bureau of Automatic equipment 040.
HYDRAULIC PARAMETERS AND CHARACTERISTICS
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