When selecting a ball valve, it is important to consider safety, reliability, media compatibility, suitability for the environment and other application criteria. It is the installer’s and/or system designer’s responsibility to ensure that these valves are installed in accordance with current ANSI B31 standards.
Manual Ball Valves
Air Actuated Ball Valves
Electric Actuated Ball Valves
Valve Port Size
Flow Rate (Cv)
Pressure/Temperature Limits
Fluid Compatibility
Pressure Relief
Installation
Manual Ball Valves
Ball Valves are reliable and simple to use shut-off valves. Manual valves require just a quarter turn of the handle to open or close the valve. Handle position lets you see the valve’s position. Manual valves are not designed for throttling. Ball valves are available in a variety of materials including bronze, carbon steel and stainless steel.
Air Actuated Ball Valves
Air actuated ball valves offer the following advantages over many standard solenoid valves – higher flow rates, lower resistance to flow resulting in lower pressure drop, higher pressure ratings, wider range of media compatibility, no minimum pressure requirements for the media (differential pressure) and smoother operation (reducing water-hammer). Single-acting spring return actuators will return the ball valve to the normal position in the event of an air system or power failure, a small 3-way pilot valve is required to control this operation. Double-acting actuators use air pressure to both open and close the ball valve; typically a 4-way valve is used to control this operation. Solenoid air pilot valves can be direct mounted to the actuator or supply an air pilot signal from a remote location. The cycle time for the air actuator to open or close is often under one second.
Electric Actuated Ball Valves
Electric actuated ball valves offer the following advantages over many standard solenoid valves – higher flow rates, lower resistance to flow resulting in lower pressure drop, higher pressure ratings, wider range of media compatibility, no minimum pressure requirements (differential pressure), and smoother operation (reducing water hammer). An electric motor and gear drive within the electric actuator rotate the ball within the valve. Two electrical circuits are required – one for opening and one for closing the valve. The valve will not return to a safe position in the event of a power failure. Electric actuators offer the advantage of operation using electricity only, no pneumatic signals required.
Valve Port Size
Most of our ball valves use the standard NPT (National Pipe Thread) pipe port connection. In addition to the valve pipe size, the port size (orifice or flow path) through the valve may also vary. Ball valves will have one of the following port sizes – standard port, full port or reduced port. Factors influencing the selection of pipe and port size include the system’s existing or designed pipe connection sizes and the flow requirements (Cv) of the application.
Flow Rate (Cv)
The Cv (flow factor) is used as a method of rating the valve capacity in terms that relate to all operating conditions. The Cv value is the number of GPM of water (at 60 F) that, when flowing through the valve, causes a pressure drop of 1 PSI.
Pressure/Temperature Limits
The maximum working limit of the ball valve is marked on the valve body. Never exceed this “WOG” (water, oil, air or inert gas) rating which is specified up to 100 degree F. Temperatures higher than 100 degree F decrease the maximum working pressure limit of the ball valve. Refer to the appropriate pressure/temperature chart included with the technical specifications of each valve. Provide a means to protect valves from freezing and bursting with liquids. When selecting an air or electric actuated valve, consider in addition to the ball valve temperature, the working temperature range of the actuator.
Fluid Compatibility
Consider the corrosive, erosive and adhesive effects of fluids on the valve and piping components. Ensure that the valve body, seals and other materials of construction are compatible with the fluid media and the environment.
Pressure Relief
Determine and provide corrective action against excessive pressure build up in the valve or piping system due to thermal expansion. Thermal expansion can create extreme pressures well above the working pressure limit of the valve, which can cause leaking or bursting of the valve.
Installation
The use of PTFE pipe tape as a sealant is acceptable for threaded valves when making joints. Correct lubrication of stainless steel pipe threads is especially important to prevent thread galling. Do not apply excessive torque when installing the valve to prevent distortion or damage to the valve.
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