What is torque?
Torque is a force tending to rotate a body about an axis.
(Example): force on a wrench tending to rotate a nut around a bolt.
How is Torque expressed?
Torque always has two parts, force and distance, and is expressed as the product of the two.
(Example): Torque = force x distance. Torque = pounds x feet. Torque = Newtons x meters.
Does that express Torque fully?
Well, not quite. Direction such as clockwise or counterclockwise must be included to express torque fully.
(Example): Torque = force x distance. Clockwise. Torque = lbft CW.
Why is Torque expressed as force x distance rather than distance times force?
Torque is expressed as force x distance to distinguish it from Energy which has the same units but is expressed as distance x force.
(Example): 100 lbft Torque. 100 ftlb Energy.
Valve Handwheel Torque and Rim Pull:
Valves are often operated by turning a Handwheel. Operating torque is applied by pulling on the Handwheel Rim. That’s called, Rim Pull. The amount of applied torque depends on the Rim Pull and the Handwheel size. Applied torque = Rim Pull x Handwheel center to Rim distance. Or Torque = Rim Pull x Half the Handwheel diameter. (Example): 80 lb Rim Pull on a 24 inch Handwheel: Torque = 80 lb x 24/2 in = 960 lbin or 960 lbin x ft/12 in = 80 lbft.
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Valtorc Valve News and Industry Related News, How-To's and FAQ's
What is torque?
A butterfly valve is a type of quarter turn valve. A quarter turn valve can open or close whenever the handle is turned 90 degrees (a quarter of a turn). The main function of these valves is to control the flow of liquids through a section of pipe. Butterfly valves are mainly used in waste treatment systems. They are extremely durable and need minimal maintenance.
Butterfly valves operate like other quarter turn valves. Understanding the way a basic butterfly valve works is pretty simple. It can help you to learn more about the components of valves.
Butterfly valves are made of a number of components. The most important one is the metal disc. This metal disc is the one commonly referred to as the butterfly. The butterfly is mounted on a rod and when the valve is closed it blocks passage of fluid. When the valve is fully open, the metal disc or butterfly moves a quarter turn. The passageway is unrestricted allowing fluids or air to pass.
In essence, the movement of the disc will depend on whether the valve is open or closed either partially or completely. If the valve is opened partially, it means that the disc will not be rotated a full one quarter turn, thus it cannot provide unrestricted passage. This means that, smaller amounts of fluid or air will pass through. However, if the valve is opened completely, the disc will be rotated 90 degrees then larger amounts of air or fluid will pass through.
There are many other components that form the butterfly valve. They include the resilient seat, body, packing, a stem and an actuator. The resilient seat is mounted on the body of the butterfly valve in order to provide the proper seal. The packing provides an additional seal especially in case the resilient seat is damaged.
Butterfly valves are configured differently. There are some which operate manually whereas others operate electronically depending on the system. They also come in different styles. There are those which offer high performance in systems like large pump lines and front suctions.
Butterfly vales can also be used in automobile systems. For instance, you will find the butterfly valve inside the carburetor of a car. In this case, the valve is used to control the flow of air to the car’s engine. It can partially open and close to regulate the amount of air passing through.
What is a ball valve? It's a question new customers often ask us at Valtorc, so let's look into this to answer the question and explain what a ball valve is.
A ball valve is described as a mechanical device that directs, guides and modulates the flow of various types of liquids by way of an opening of a ball which has an opening in the middle. The opening is referred to as the port. By turning the handle on the ball valve, this manually opens/closes the port which controls the pressure from the flow of the liquid. Durability and “perfect” shutdown/shutoff are what makes the ball valve advantageous over other type of valves.
Valves are found in our everyday living and may go unnoticed. For example, there are plumbing valves which are at our sinks in our spigots. There are valves inside our washing machines, dishwashers, gas fireplaces, outside water spigots, refrigerators and more. Various types of industries utilize valves for their productions. Such industries include electronics, power, automotive, printing, plastics, textiles, metal, medical, chemical and food, to name a few. The industries that utilize ball valves typically have a need for supporting high pressure and temps exceeding 480 degrees. Ball valves are simplistic to operate and repairs are made easily without being removed from their pipeline.
Being made of steel, brass, iron, bronze or PVC, ball valves can range in sizes from .2 to 11.81 inches. More complex control systems using valves that need to regulate flow through a pipe will need an actuator. The actuator controls the valve pneumatically or is motor-operated and keeps it positioned appropriately so that the flow of the liquid is precise to the changing pressures and flow levels.
The basic types of ball valves include Full Port, Reduced Port, V-port, Multi-port, Standard Port and Cavity Filler ball valve. There are 3-way and 4-way ball valves. Depending on the application would determine the type of ball valve being used. The specifications to be considered for determining the appropriate ball valve would be the temperatures and pressure, number of ports, valve size, type of body material, end connectors and configurations.
There are various butterfly valves being utilized in every industry imaginable. The butterfly valve, aka quarter-turn valve, is one of the most popular and economical valves. You may not realize it, but you encounter butterfly valves on a daily basis. These valves, made of carbon steel, cast iron, stainless steel or plastic, are being utilized in many applications where assorted types of fluids, gas, air, steam are being controlled by shut-off or throttling. This valve is excellent for shut-off applications and the disk can completely block the passageway for fluids.
The body of a butterfly valve is comprised of a metal disk with a rod that runs through the disk. The rod is connected to an actuator or a manual lever which controls the disk turning it parallel or perpendicular to the flow. Depending upon the application, the disk can be made of plastic, steel, carbon steel or stainless steel. There are different options of actuators for this valve: pneumatic, electric and electro-hydraulic, manual and a gear type.
There are 3 types of butterfly valves. The standard butterfly valve is the concentric butterfly valve. The disk is metal with a rubber seat. Next, is the doubly-eccentric butterfly valve consists of various types of material for the disk and seat. This one is more of a high-performance valve. Lastly, the triply-eccentric butterfly valve (known as triple offset butterfly valve) is utilized when the application requires tight shut-off when gas or oil are involved. Being the most of expensive of the butterfly valves, the seats are typically laminated or metal in design.
Butterfly valves can be wafer or lug style. You will see wafer style valves installed when the valve is between pipe flanges. Lug style simply means that there are holes machined so that it can be bolted to the flange. These valves are typically used in HVAC applications, water systems, OEM, or irrigation for positive shut-off. Lug style will be a bit more expensive and are used at the end of the line.
When it comes to ordering butterfly valves for your specific application, you want to make sure that you are ordering from reputable and experienced company such as Valtorc International. Before you order, please know what element(s) you are dealing with, know the size needed, type of material and pressure flow, if possible. We can offer an assortment of trim features to ensure a perfect match for your particular valve needs.
What is a V-Port Ball Valve? When it comes to ball valves, the V-port ball valve plays an important role in the valve world. This V-shaped ball or V-shaped seat is utilized with higher velocity applications that would otherwise damage a normal ball valve. These ¼ turn control valves can be flanged or non-flanged. The seats can be rigid or flexible metal or PTFE which is a synthetic fluoropolymer better known as Teflon. The V-port ball valve is also used when precision cannot be sacrificed because corrosive liquids (clean or dirty) or gases going through the piping system need to be sustained to critical and controlled specifications.
It is imperative that you provide the following specifications to a quality and knowledgeable valve company so not to over or under-size your V-port ball valve:
- Description of your application
- Type & pressure of media
- Flow Rate
- Inlet pressure
- Line Size
- Pressure Drop
Failure to report accurate specs can risk the success of your line. If you over-size your valve, the pressure drop will not be accurate and will affect the flow through your handling system. If under-sized, you will over work the pump on the system.
Valtorc International is a leader in the industry when it comes to the V-port ball valve. Our valves are ARRA compliant and range in size from ½” to 12” and available in carbon steel, stainless steel, brass and cast iron.
Valve actuators are of various types namely electrically operated , pneumatically operated.
- Pneumatically operated actuators can be diaphragm operated for globe , gate valves.
- Pneumatic actuators can be quarter turn type for ball or butterfly valves.
- Pneumatic actuators can be cylinder operated for say Knife gate valves.
- Actuators are again single acting spring return type or double acting.
- Again electric actuators can be classified as on-off type or control ( modulating type).
On- off pneumatic actuators can be operated with solenoid valves . As you mention the fluid to be natural gas, you have to select solenoid valves which are intrinsically safe at the same time these valves may be placed at a safe distance from the valves and piping. These valves are again actuated by controllers( on -off , PID) connected to the level switches, pressure sensors or temp sensors as the case may be.
To control flow rates, you need to use a pneumatic control valve with a pneumatic positioner operating on (0.2-1 kg/cm2) with current to pressure convertor or an electroneumatic positioner ( 4-20mA control signal). These can be used to control flow rate or downstream pressure. Other elements required are pressure or flow sensors, PID controllers.
The control again depends on how the plant is operated ie DCS or PLC controlled.
If it a simple requirement then the actuatar can be made to operate on a system of limit switches. While selecting an actuator the fail safe mode ( in case of power, signal or air failure) should also be taken into consideration , which is specified by words like normally open or normally closed etc.
If you are in the valve world at all, you know that the plug valve oftentimes gets a bad rap. There are different reasons for this. One being that the maintenance for these valves is greater than that of other valves. They need to be lubricated while out in the field and more times than not, this is overlooked.
Secondly, due to the corrosiveness and high temperatures of the substances flowing through the plug valves, they tend to wear much quicker than that of some other valves. This means they require patching and maintenance on a regular basis.
Lastly, the plug valve is not the valve of choice when it comes to throttling. You will want a v port, butterfly or ball valve in those types of applications.
On a good note, the plug valve does not clog. And one of the most common uses for a plug valve would be in our homes or businesses where we utilize gas services. The brass, 2 port valve, which is used in gas lines, is conically shaped and its structure bares a handle. When the handle is turned to 90 degrees from the inlet and outlet ports of the valve, the valve flow is shut off. For the gas to flow though the pipes, the handle and plug would need to line up with the inlet and outlet ports of the valve body.
A straightforward description of a plug valve is best described as a rotational valve with a tapered disk resembling that of a plug.This plug or disk sits “long ways” in the valve and has a passageway bored through the center in order to accommodate passing air or fluids. This type of control for corrosive or high temperature air/liquids is economical and simple. With a 2 port valve there are two positions, open and shut. There are also multi-port valves available in the plug valve for different more complex type applications. In applications where there are more than 2 ports, you may have a need for a soft rubber overlay for a sure-tight shut off.Different types of seals are based upon gaskets. Some plug valves close against the gasket and some close directly on the seat.
Many oil field service companies, vacuuming devices and applications which are dealing with glassware stopcocks which create glass products, still utilize plug valves. It does indeed seem to be a dying breed of valves, but with the right material, the proper gasket/seat in a particular application, you may see that a plug valve can be successful for you…especially when expenses plays a factor in your decision.
To assist you better with your valve decision, make sure you contact your Valtorc sales specialist today. They can better educate you on what’s best for you and your application to obtain the maximum results of success.
We all know that valves are present in our everyday lives, but valves work a lot “behind the scenes”—controlling what might seem like the “uncontrollable”. Without valves, we would have engineering issues on how to regulate and control steam, water, air, corrosive liquids, gases and other materials. You can already see WHY valves are important, but WHERE did valves originate, you ask? Good question…
Maybe ancient man watched the beaver as he built his dam across the river. In ancient times, man used tree trunks, thick grasses, rocks, boulders and branches to regulate water. The Egyptians and Greeks also designed valves to lead water to irrigate their crops and provide water to their villages. However, the Romans were the ones to truly develop their canal systems and had a higher engineered technology behind those systems. Due to various country invasions, one may be led to believe that the Romans stole some of their technologies that they utilized. Either way, the Romans took their technology findings on to further develop the bronze plug valve which enabled them to distribute water to buildings.
It was not until the Industrial Revolution that valves really evolved to the next level. Steam was the power required to reform and strengthen this era and replaced muscle or “horse” power. Valves along with the patented steam engine made it possible to pump water out of mines. During this time, the US was able to increasingly provide mining jobs to those out of work. Mining, agriculture, textile mills, manufacturing plants, steel production, transportation and many other industries were emerging quickly. The economy exhibited unprecedented growth and life was getting better financially for most. Water and steam along with the evolution of the valve, contributed highly to the success of the Industrial Revolution industries.
Today, there are diverse types of valves made of materials such as stainless steel, carbon steel, cast iron, bronze, brass, PVC, CPVC and other alloy materials. Valves can be very small in size or up to 102 tons, which is the largest valve in the world! (See http://www.valveworldexpo.com/cipp/md_valve/custom/pub/content,oid,1943/lang,2/ticket,g_u_e_s_t/local_lang,2) The application determines what type of valve you would need in order for your line to be successful. When ordering your valves, you want to ensure that you work with a reputable company such as Valtorc International. They will want to know all aspects of your application to determine which type of valve(s) would be best suited for your needs. Here is something else to think about—ask the supplier/manufacturer if their products are made in the US. Let’s strengthen our economy and keep sales in our country when we can!
API SPEC 6D
Specification for Pipeline Valves. API Specification 6D is an adoption of ISO 14313: 1999, Petroleum and Natural Gas Industries-Pipeline Transportation Systems-Pipeline Valves. This International Standard specifies requirements and gives recommendations for the design, manufacturing, testing and documentation of ball, check, gate and plug valves for application in pipeline systems.
Bolted Bonnet Steel Gate Valves for Petroleum and Natural Gas Industries - Modified National Adoption of ISO 10434:1998.
Metal Plug Valves - Flanged, Threaded and Welding Ends. A purchase specification that covers requirements for metal plug valves with flanged or butt-welding ends, and ductile iron plug valves with flanged ends, in sizes NPS 1 through NPS 24, which correspond to nominal pipe sizes in ASME B36.10M. Valve bodies conforming to ASME B16.34 may have flanged end and one butt-welding end. It also covers both lubricated and nonlubricated valves that have two-way coaxial ports, and includes requirements for valves fitted with internal body, plug, or port linings or applied hard facings on the body, body ports, plug, or plug port.
Compact Steel Gate Valves - Flanged, Threaded, Welding, and Extended-Body Ends. The standard covers threaded-end, socket-welding-end, butt-welding-end, and flanged-end compact carbon steel gate valves in sizes NPS4 and smaller.
Corrosion-Resistant, Bolted Bonnet Gate Valves - Flanged and Butt-Welding Ends. The standard covers corrosion-resistant bolted bonnet gate valves with flanged or butt-weld ends in sizes NPS 1/2 through 24, corresponding to nominal pipe sizes in ASME B36.10M, and Classes 150, 300, and, 600, as specified in ASME B16.34.
Butterfly Valves: Double Flanged, Lug- and Wafer-Type. The standard covers design, materials, face-to-face dimensions, pressure-temperature ratings, and examination, inspection, and test requirements for gray iron, ductile iron, bronze, steel, nickel-base alloy, or special alloy butterfly valves that provide tight shutoff in the closed position and are suitable for flow regulation.
API STD 594
Check Valves: Flanged, Lug, Wafer and Butt-welding. API Standard 594 covers design, material, face-to-face dimensions, pressure-temperature ratings, and examination, inspection, and test requirements for two types of check valves.
Valve Inspection and Testing. The standard covers inspection, supplementary examination, and pressure test requirements for both resilient-seated and metal-to-metal seated gate valve, globe valve, plug valve, ball valve, check valve, and butterfly valves. Pertains to inspection by the purchaser and to any supplementary examinations the purchaser may require at the valve manufacturer's plant.
Fire Test for Soft-Seated Quarter Turn Valves. The standard covers the requirements for testing and evaluating the performance of straightway, soft-seated quarter-turn valves when the valves are exposed to certain fire conditions defined in this standard. The procedures described in this standard apply to all classes and sizes of such valves that are made of materials listed in ASME B16.34.
Specification for Fire Test for Valves. The standard covers the requirements for testing and evaluating the performance of API Spec 6A and Spec 6D valves when exposed to specifically defined fire conditions.
Metal Ball Valves - Flanged and Butt-Welding Ends. The standard covers Class 150 and Class 300 metal ball valves that have either butt-welding or flanged ends and are for use in on-off service.
A full port ball valve has an oversized ball so that the hole in the ball is the same size as the pipeline resulting in lower friction loss. Flow is unrestricted, but the valve is larger.
A standard port ball valve is usually less expensive, but has a smaller ball and a correspondingly smaller port. Flow through this valve is one pipe size smaller than the valve's pipe size resulting in slightly restricted flow. In reduced port ball valves, flow through the valve is one pipe sizes smaller than the valve's pipe size resulting in restricted flow.
A v port ball valve has either a 'v' shaped ball or a 'v' shaped seat. This allows the orifice to be opened and closed in a more controlled manner with a closer to linear flow characteristic. When the valve is in the closed position and opening is commenced the small end of the 'v' is opened first allowing stable flow control during this stage. This type of design requires a generally more robust construction due to higher velocities of the fluids, which would quickly damage a standard valve.
A trunnion ball valve has a mechanical means of anchoring the ball at the top and the bottom, this design is usually applied on larger and higher pressure valves(say 4 inch and above 600 psi and above)
Manually operated ball valves can be closed quickly and thus there is a danger of water hammer. Some ball valves are equipped with an actuator that may be pneumatically or motor (electric) operated. These valves can be used either for on/off or flow control. A pneumatic flow control valve is also equipped with a positioner which transforms the control signal into actuator position and valve opening accordingly.