Pneumatic Actuators – Enolgas USA

FEATURES OF BALL VALVES

Vittorio Bonomi — Sun, 15 Jul 2018 13:52:58 +0000

NOMINAL DIAMETER

The nominal diameter is indicated on the body of the valve in inches or by “DN” followed by the value is mm unit of measure, which corresponds to the size expressed in the inches, e.g.: DN20 is equivalent to ¾ inch NPT or BSP connection.

2. EFFECTIVE DIAMETER

The effective diameter indicates the actual port diameter in the ball. This equals the nominal diameter of the ball only in the case of a full-bore valve. In case the actual port diameter in the ball is one size smaller than the valve’s size, (e.g.: ¾” ball valve with ½” port in the ball) the valve is referred as “reduced-bore.” While in case the actual port diameter in the ball is in between the valve’s size and the one size smaller, (e.g.: ¾” ball valve with 5/8” port in the ball) the valve is referred as “standard-bore.”

3. FLOW COEFFICIENT

The CV value is an indication of the capacity of a valve and is often used to describe the performance of control valves. The CV coefficient is often used to describe the hydraulic characteristics of elements in a pipeline. The definition of CV is the number of U.S. gallons per minute (GPM) of 60 F water flowing through a valve results in a 1 pound per square inch (psi) pressure drop across the device.

4. USE

It is essential that the limits set by the manufacturer are observed to achieve the best results from the valve. If are used higher temperatures and pressures, than recommended, the natural elasticity of the Teflon will be exceeded, and permanent deformation will result in leakage.

5. RESISTANCE TO CORROSION

The table of chemical compatibilities indicates the suitability of brass material and other materials for use with various fluids. However, the table is not designed to provide a complete answer to all applications. Please contact your Enolgas USA Inc. representative or directly Enolgas USA Inc. for clarifications.

6. PRACTICAL TESTS

In the circumstances involving unusual applications, it is often safer to carry out a practical test to determine the compatibility of the fluid to the brass and Teflon. Obviously, there are instances where theoretical information and experience are not available as a guide.

In ball valves, the loss of head is increased by the square of the reduction bore; this means that a small bore reduction will result in a large loss of head.

However, the situation is not improved by using a hollow ball. Head loss becomes greater due to turbulence within the ball. Tests show that in a hollow full-bore valve the loss head is 42% greater than a standard full-bore valve. A ¾” valve, (DN 20), hollow full bore ball is capable of passing less volume of fluid in one hour than a DN15 valve with regular full bore ball. (i.e., one size smaller has larger capacity).

7. PERFORMANCES

The performances of ball valves are shown in the diagrams with the interaction between temperature and pressure. The horizontal line indicates the temperature and the vertical axis indicates the pressure in PSI/BAR (atmospheres). Each co-ordinate delimits the field of use of a given size of the valve.

8. CHOOSING A BALL VALVE

When selecting an item, it is essential that both quality and price factors are considered. If two products appear visually similar, there is a natural tendency to select the product with the lower price. However in the case of a ball valve the external appearance is not the most important aspect (assuming that the finish and thickness of materials are similar) in selecting the correct valve to give trouble-free long life. Therefore it is preferable to determine the level of quality and then compare the costs.

FACTS ABOUT BALL VALVES

Vittorio Bonomi — Thu, 12 Jul 2018 12:28:40 +0000

2-way brass ball valve with iso top flange Enolgas USA

Ball valves with Teflon seals have some unique characteristics that you cannot find in other types of traditional valves, such as butterfly valves, plug valves, gate valves, solenoids valves, etc. Ball valves have the best ratio among pressure, flow rate and price.

The specific characteristics of ball valves are:

THE SECURITY OF SEAL

The seal is hermetic under normal conditions. Teflon seals can adapt to the relevant surface due to the precise loading, which can be obtained. Once operative the seal remains constant and the wear is limited, due to self-lubricating properties of the material. Teflon seal is elastic and can re-adapt to its original shape, provided expansion or contraction of the valve keeps the deformation within acceptable limits. Unlike most valves, the ball valve obtains a secure seal due to the inlet pressure of the fluid, compressing the ball against the opposite seal proportional to the actual inlet pressure.

VARIETY OF APPLICATIONS

Ball valves with Teflon seals are suitable to most fluids, which are compatible with brass, e.g.:

Gases: Methane, Ethane, Propane, Butane, Argon, Freon, Oxygen, etc.
Oils: vegetable, mineral, synthetic, hydrocarbons in general and all carbon fuel derivations such as Diesel, Petrol, Kerosene, etc.
Sundry: air, cold and hot water, low-pressure steam to a maximum of +248°F (+120°C)

VERSATILITY

Ball valves are suitable for low and medium pressures as well as vacuum conditions. They are ideal for both low and high temperature from -4°F +302°F (20°C to + 150°C) respectively.

PORT CAPACITY

Ball valves have a port with a circular section equal to the tube; therefore there is no turbulence in the flow, and this, in turn, reduces the loss of pressure head.

FUNCTION

Ball valves give the operator an immediate visual position of the valve status even at a distance. When the handle is parallel, to the valve and pipe, the valve is open. When the handle is at a right angle, (perpendicular) to the valve and pipe the valve is closed. The on/off operation is quickly and positively achieved by a ¼ turn of the handle, and therefore confusion and mistakes are minimized. Rotation of the ball in operation continually cleans the surface and therefore eliminates contaminants, which could cause a leak in conventional valves.

MAINTENANCE-FREE

Ball valves eliminate the need for lubricating materials due to the self (dry) lubricating properties of Teflon. Therefore a contaminant-free environment exists, and possible causes of leakage are reduced to a minimum. Because the valve and seals are constructed to close tolerances, it is unnecessary to carry out adjustments (or maintenance) during the life of the valve.

DESIGN

Ball valves are designed and constructed to fit comfortably into a pipeline, with a minimum of bulk, while retaining strength and durability for the life of the valve. The handle operation of a ball valve can be made left or right hand, while the flat handle can be replaced with a tee-handle the clearance is a problem in cramped spaces.

For an more information, visit www.enolgasusa.com or the Enolgas USA blog, Facebook, Linkedin, Twitter and YouTube.

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Flow Simulations

Vittorio Bonomi — Mon, 12 Feb 2018 14:00:48 +0000

Computational fluid dynamics (CFD) is a branch of fluid mechanics that uses numerical analysis and data structures to solve and analyze problems that involve fluid flows. Computers are used to perform the calculations required to simulate the interaction of liquids and gases with surfaces defined by boundary conditions. With high-speed supercomputers, better solutions can be achieved. Ongoing research yields software that improves the accuracy and speed of complex simulation scenarios such as transonic or turbulent flows. Initial experimental validation of such software is performed using a wind tunnel with the final validation coming in full-scale testing.

At Enolgas USA, CFD is available for specific process and requests. Check out our Technical Support, the Conversion Calculator and the Flow Coefficient Calculator.

Different Types of Actuators

Henry Nigel — Fri, 15 Dec 2017 14:53:13 +0000

Actuators are mechanical or electro-mechanical devices that provide controlled movements to a connected mechanism or a linear or rotary system. However, the system needs a power source to function properly. Here’s a list of the different types of actuators, their uses, and how each works.

Hydraulic Actuators

A hydraulic actuator uses pressurized liquid to facilitate mechanical operations in many industrial settings. Because liquids are incapable of being compressed, hydraulic actuators can supply force far beyond that of any other type of actuator, often up to 4,000 pounds per square inch (PSI). Because hydraulic actuators use pressurized liquid, they can supply power even from a far distance. As a result, these actuators are usually used for offshore drilling and exploration.

Electric Actuators

Powered by a motor that converts electric into mechanical torque, electric actuators are the most popular type of actuator. Electric actuators don’t require oil, so they’re much cleaner than some of their counterparts. In addition, electric actuators are easily reprogrammed and networked, offering immediate feedback for diagnostics and maintenance.

Electric actuators come in both linear and rotary format, and each serves a different purpose. A linear electric actuator moves valves and other mechanisms in a straight line using belts, screws, and coils. Typical uses for these actuators include locking doors, braking machine motions, and opening and closing dampers. Electrical rotary actuators provide rotational movement applications. A range of industries uses this type of electrical actuator, especially in the robotics industry.

Pneumatic Actuators

Pneumatic actuators convert energy formed by air or a vacuum into linear or rotary motion. The air in these types of actuators comes from an external compressor or a manual pump that forces air into a cylinder with a piston. The piston then begins to move, creating the energy needed to move valves open or closed.

The easiest way to understand a pneumatic actuator is to think of it as a hydraulic actuator that uses air instead of liquid. These actuators are efficient, creating huge changes in the system from small alterations in pressure, and also operate more quietly than hydraulic actuators.

Mechanical Actuators

A mechanical actuator is the simplest of all actuators, using physical parts to convert rotational to linear motion. Rack and pinion steering on cars or turning an outdoor faucet on or off are the most common examples of this type of actuator.

Thermal/Magnetic Actuators

A thermal or magnetic actuator uses either heat or magnets to turn an electric current into mechanical energy. Most often, these actuators use shape memory alloys, which are metals that can return to their original shape even after heating or distortion. These actuators tend to be economical, lightweight, and easy to construct, so they are applicable to a variety of industries.

When you need actuators for any type of project, Enolgas USA is the only company you need to get in touch with. We provide a massive selection of actuators, as well as product knowledge so you can get the job done. Make sure to contact us today for all of your actuator needs.