Learn About Valve Options
Mounting: The typical ANSI 150 # and DIN drilling is used as an industry standard for heavy duty and high-performance models. Quick clamps can also be used for applications up to 30PSI (2bar) and port sizes up to 10&#;. For 1&#; to 3&#; VB ball valves NPT, Socket weld and Tri-Clamps connections are options.
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Some valves will include blind tapped holes, which may be a problem if the valve is mating with existing blind tapped holes. Another option is to choose over-sized flanges, which allows for through holes. For regular duty service valves, ANSI and DIN bolting can be overkill and alternative bolting patterns are available.
- No Clamps
- ANSI 150#
- Tri Clamps
- Gemco Mounting
- DN PN10
- Cover Clamps
- NPT
- Socket Weld Connections
Seats: Very abrasive material will tend to dictate using metal seats versus the more commonly used reinforced Teflon seats.
The metal seal will give longer life and can be used at higher temperatures than Teflon but the shut-off sealing is limited to dust tight, ANSI class IV or ANSI class V. Reinforced Teflon can be used up to 450 degrees F (230 C), and provide Class VI shut-off.
- Teflon
- Metal
- Inflatable Seat
Service: Dust tight are used for most gravity feed powder applications where the process is not under vacuum or pressure.
- Dust Tight
- Liquid Tight
- Vacuum
- Low Pressure
- Pressure
- High Pressure
O-Ring Material: Silicone O-rings are typical. Viton and Teflon Encapsulated Silicone are used for specific chemical resistance. Most other materials are available on request.
- Silicone
- Viton
- Teflon encapsulated
Operators (Actuators): Double acting pneumatic operation is the first choice for reliability, speed, weight, and value. Levers and gear drives are also available. Pneumatic operators are available in double acting or single acting (spring return) fail-safe modes. Spring return actuator are slower, bigger, and heavier.
As with other quarter turn valves; levers, gear drives or chain operators are available. Pneumatic and hydraulic, operators are available in double acting or fail-safe modes. Pneumatic operation should be the first choice for price, reliability, and speed. When handling solids a higher factor of safety is used to calculate seat torque requirements. The factor is typically 1.5 instead of the 1.25 used for liquid and gas valve calculations.
For solids that &#;set-up&#; or harden over-sized actuator and specially designed discs that can break through the hardened cake are used. Actuators are typically sized for 80-PSI (5.3 bar) pressure. If the available supply air pressure is dependably higher (100 to 120PSI) or lower (40 to 60 PSI), this will factor in the sizing of the actuator.
For fail-safe operation, spring return actuators are the norm. When a spring return type actuator is used, it is over-sized to compensate for the spring as well as the unseating, run, and seating torque required for valve operation. This can lead to weight and space problems as well as extra cost. An alternate fail-safe option is to use a double acting actuator with a pneumatic accumulator sufficiently sized to close the valve. If there is a loss of pneumatic pressure, a pressure switch activates the accumulator and operates the valve.
- No Operator
- Manual Lever
- Air &#; Double acting
- Air &#; Spring Return
Control: Single solenoid (spring return) fail closed on loss of control signal is typical. Fast acting (1 to 5 seconds), quarter turn valves are ideal for flow control of solids. A pneumatic (3 to 15 PSI) or electro-pneumatic (4 to 20 milliampere) positioner can take a signal from a manual adjusted pressure regulator, or from a computer controller. The pneumatic positioner is often used in manually operated filling stations, while the electro-pneumatic positioner is typical for variable discharge which is often used for automatic loss-in-weight systems.
- No control required
- Solenoid
- Pneumatic Positioner
- Electro-Pneumatic Positioner
Feedback: Typical for automated valves is two mechanical limit switches indicating fully open and fully closed with a visual beacon indicator.
- Position Indicator
- Visible Beacon
Electrical Classes: NEMA 4/IP64 wash down and Explosion proof NEMA 7 and 9 are standard. Other classification including IS Intrinsically Safe are offer as engineered options.
- Wash Down
- X-Proof
- Intrinsically Safe
Voltage: The Voltage of an electrical appliance indicates the voltage at which the appliance is designed to work. Typical power of a single solenoid is 7.2 Watts. The current consumption at that voltage is displayed on a rating plate attached to the appliance.
- 24V DC
- 120V 60
- 240V 50 Hz
Clean in Place (CIP): For automatic cleaning, spray balls or jets should be considered. Another option is the Sani K Valve that can be dismantled by hand for inspection and cleaning. For safety reasons the size of such valves are typically limited to an 8&#; port diameter due to the weight of individual components.
CIP ports is a 1-1/2&#; ferrule fitted with a Teflon plug, cap and quick clamp. Spray ball is supplied with cap and plug to be used if spray ball is removed between cleaning cycles.
- No CIP required
- CIP port
- CIP Spray Ball
Ball valves are versatile flow control devices suitable for extensive industrial applications. They are available in different sizes and designs, making them adaptable to diverse sanitary, petrochemical, and cryogenic applications.
These valves control the flow of fluids through a hollow, pivoting ball that is either a full or reduced port. The dimensions of full port valves are equal to the internal diameters of the adjacent pipelines. The dimension of a reduced port (standard port) valve diameter is one pipe size less than the internal size of the adjacent pipe. For example, a 1&#; reduced port valve will actually use a ball with a ¾&#; port diameter.
Ball valves have several advantages over other industrial valves, with the most notable being:
They provide leak-tight seals.
They can open and close quickly.
They are more durable than most other industrial valves.
There are several ways to categorize valves. Each category or design determines the performance characteristics of the valve. The categories include:
Valve design based on ball movement: Floating and trunnion mounted
Port design: full port, standard, or V-port valve.
Body style: single body, split, top-entry, 3-piece or welded body.
There are a few questions that industrial engineers must ask before choosing ball valves. Finding answers to these questions guides the experts through the challenging valve selection process and helps select reliable ball valves that satisfy the requirements of the piping system. What are these questions?
1. What type of media will flow through the ball valve?
The first question that the engineers must address is the type of fluid that passes through the pipeline. Is it a liquid, gas or semi-solid (slurry)? Understanding the physical and chemical characteristics of the fluid helps analyze its behavior as it flows past the valve. Understanding the nature of the service fluid is vital for making decisions about valve materials, port designs and valve sizes. For example, when choosing a gas ball valve we must take into account its performance and reliability issues when working with combustible gases, like hydrocarbons, liquified natural gas or chemical vapors.
2. Which actuation methods will you use?
Pipeline designers must specify the type of valve actuation that will complement flow control operations. There are piping systems that require frequent valve operation and high precision levels. Other flow operations require a one-off activation of the ball valve. When choosing ball valves, the designer needs to quantify the frequency of valve operations. They also need to evaluate the energy requirements and complexity of actuation technologies. The available actuation methods for ball valves include:
Pneumatic actuation
Electric actuation
Manual operation
Hydraulic actuation
Evaluate additional actuation options like spring return or double-acting actuators as well. Understand the impact of add-ons like limit switches or pilot valves on the reliability of valves.
In processes that demand fast cycle times, pneumatic actuation for ball valves seems to be the most suitable choice. Engineers can install manually-operated ball valves in strategic pipe locations to facilitate pipeline isolation for maintenance or inspection. These low-cycle valves require operation a few times a year.
3. What are the temperature and pressure ratings of the pipeline?
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Specifying the pressure and temperature conditions of the service fluid and the working environment is critical when selecting ball valves. The temperature ranges of the service fluid can alter the mechanical strength of the valve. If the temperature fluctuations are too high, the valve experiences non-uniform expansion and contraction that may lead to surface fractures with time.
Ball valves should sustain the pressure of the service fluid. Exceeding the designed pressure limits affects sealing quality and can cause premature wear. Select a ball valve with temperature and pressure ratings equal or higher to the ratings of the pipeline.
4. What are the estimated annual cycles?
The frequency of valve cycling affects the durability of a ball valve. Engineers should estimate annual operating cycles to determine the durability of different ball valves in the piping system. Other factors like maintenance and media abrasion affect the reliability of valves throughout their lifecycle.
The designers should estimate life expectancy of ball valves before choosing the actuation mechanism. If properly specified, ball valves can survive several tens of thousands of operations without failure. After understanding the cycling requirements, the engineers may settle on pneumatically actuated valves that guarantee better durability and reliability than electrically actuated counterparts.
5. How do you intend to use the ball valve?
While there are different types and brands of ball valves in the market, each has a definite application area. For instance, a steel ball valve for a chemical processing facility may not meet the specifications for use in a sanitary application. Ball valves provide shut-off for pipelines and can also provide directional control of fluids. When making selections for application-specific valves, the designer should understand whether:
The valve exclusively shuts off the flow.
The valve switches flow between sources.
Splits flow from one source to two different destinations (applies to 3-way ball valves).
Industrial applications operate under different pressure and temperature conditions. There are strict emission and leakage control requirements attached to diverse classes of ball valves. When selecting the ball valve, ensure that it meets minimum system requirements and regulatory specifications.
7. Which materials are used to manufacture the valve?
The type of valve materials comes down to the properties of the service fluid. When evaluating valve materials, engineers should verify:
The most common materials for ball valve bodies are brass, stainless steel, plastic, Monel, Inconel, Molybdenum, Chromium alloys, nickel alloys or copper. Severe service ball valves require materials with better strength and corrosion resistance values like Monel or Inconel.
When examining valve materials, the designers should pay attention to the composition of seal materials. Soft-seated ball valves may use rubber seals or PTFE seals. For extreme fluid service, the ball valves feature metal-to-metal seats.
Which testing and quality assurance procedures does your valve vendor use?
When working with vendors or manufacturers, the company should request information about testing protocols and quality assurance measures that they use. Testing procedures analyze the performances of different ball valves, leak and emission tests and pressure tests to ensure valves are safe for specific applications.
Do not purchase ball valves because they are the cheapest in the market. Take an extra step to evaluate the quality assurance criteria and standardization marks on the valve body or packaging. There is no point in purchasing ball valves in bulk, only for them to fail after a few working cycles.
8. What certifications should the valve have?
The application of ball valves spans different industries. In each sector, appointed organizations certify products to verify compliance with health and safety regulations. Depending on the type of application, ball valves and their actuators are subject to the following certifications:
ANSI certifications: Determines the pressure and temperature ratings for pipe flanges.
NEMA certifications: Sets the standards for the design of electrically actuated ball valves.
NSF certifications: Provide guidelines for selecting ball valves in food, beverage and drug production facilities.
Ball valves should have certifications relevant to the fluid applications you are running within the facility.
9. What are the maintenance requirements for ball valves?
Ball valves do not typically require a high volume of maintenance interventions. They have simple flow control mechanisms and are less likely to fail. However, that does not preempt the fact that industrial valves, at times, will require maintenance. When selecting valves, establish a plan for inspection and maintenance. Maintain a lean inventory of repair and replacement parts like seals for valves and consumables for actuators. Manual ball valves may require fewer maintenance interventions than actuated valves.
Conclusion
Selecting ball valves for different industrial applications is not a simple process. It requires a careful review of the technical specifications of the pipeline, a balanced selection of manufacturing materials, and research on the different valve industry codes and standards. By answering the above questions, engineers and pipeline designers can make informed decisions and select reliable ball valves that provide long-term service.
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