Daily Archives: April 24, 2017

Cassette Sprocket Buying Guide

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What is a bicycle cassette?

A bicycle cassette is the cluster of sprockets on your bike. The cassette is normally situated on the rear hub of your bike; slotting onto a freehub body, and held firmly in place with a threaded cassette lockring. Depending on the ‘speed’ of your bike, your cassette could have anything between a 5 and 12 sprocket; most modern bicycle drivetrains utilize either 9, 10 or 11 speed cassettes.

 

Why are cassettes important?

Cassette sprockets provide you with a range of gearing options that your chain can run on. The range of gear ratios allows you to vary your pedaling cadence (revolutions per minute), to achieve optimum efficiency.

 

Running your chain on one of the larger sprockets (more teeth) on the cassette will provide an “easier” gear; letting you turn your legs faster. Running your chain on a sprocket with a lower number of teeth, will allow you to keep pushing power through your drivetrain, without “spinning out” (pedaling at an uncomfortably high number of revolutions) on a downhill section or sprint. A good range of gears on your cassette, therefore allows you to select the optimal gear to use; to keep your pedaling as smooth and as fluid as possible.

 

How do you choose the right cassette sprocket for your bike?

The choice of a cassette sprocket can appear overwhelming at first glance. There are different combinations of sprockets, to suit different tastes and terrains; with a significant difference between the cassettes you would use for a triathlon bike, compared to a mountain bike cassette.

 

The main thing to consider is the spread of gears on the cassette sprocket. The closer the highest and lowest number of teeth is, the smaller the jump between gears; facilitating a smoother gear change. However, having closer geared sprockets will normally decrease the size of the largest sprocket on the cassette; leaving you with a gear ratio that may be less suited to climbing and tough terrain.

 

G-MA Engineering Co., Ltd. provides wide range of bicycle parts for clients. Cassette sprocket, bike seat post, MTB crankset, and so on titanium bike parts all can be found on our website. If you are interested in G-MA’s cassette sprocket or other products, welcome to browse our website or contact with G-MA directly!

 

 

Article Source: http://guides.wiggle.co.uk/cassette-buying-guide

Optimum Flow Control Contributes Towards Reducing Manufacturing Costs

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Oil and gas companies around the globe face the challenge of increasing production and delivering quality products while reducing resources and manufacturing costs. Process control has a financial impact and so reducing process variability is, therefore, a key factor in maximizing quality output and reducing costs. Comprehensive studies of control systems have shown that up to 80% of control loops have not performed satisfactorily in reducing process variability. In most instances, the control valve was found to be the major cause of the problem. Despite this, the impact of the flow control valve on dynamic performance is often overlooked.

 

Optimum flow control is imperative; choke and control valves are subject to a variety of technical phenomena and careful selection of the right control valve for each application is crucial.

 

Superior design features include the valve material, which should be resistant to the chemical composition of the flow medium. For example, discs and internals made of solid Tungsten Carbide, renowned for its erosion and cavitation resistant properties. Industrial diamond facings inserted on the discs have also produced some very good results under severe conditions. The sealing surface must not be in contact with the flowing medium to ensure seat tightness can be guaranteed for a longer period of time. The construction of the internals should ensure that the downstream of the back disc is abrasive resistant. This removes the majority of cavitation and erosive material from the sealing surfaces as well as from the valve body. The design of the internals must be able to absorb turbulence in the flow so that the outgoing flow is more laminar. Rotating choke disc valves are recommended for extremely severe applications.

 

Flow control valves are also optimized by using different shaped and sized throttling orifices in the rotating discs. This affects the Cv value of the valve and has a crucial impact on process control. The right valve size and trim must be chosen to match the process conditions.

 

For both new and existing applications, to ensure downtime is kept to an absolute minimum and additional costs are not incurred, flow control valves should ideally be engineered to fit with no modifications to existing pipework. This also ensures that any replacements can be made efficiently.

 

Ultimately, these design features coupled with repairable internals and easy maintenance maximize production output, lower life-cycle costs and extend the mean time between failures, providing an overall reduction in total cost of ownership.

 

Found in 1984, ASHUN has established a fine reputation worldwide. Our professional R & D team develops new products continuously to meet our customers’ needs. If you need more information about flow control valves or other valves, welcome to browse our website or contact with ASHUN directly!

 

 

Article Source: http://EzineArticles.com/7478601