screw compressors vs reciprocating compressors refrigeration

ArticlesLeave a Comment on screw compressors vs reciprocating compressors refrigeration

screw compressors vs reciprocating compressors refrigeration

82 0 obj endobj In many cases, users need to take breaks, the recovery time, to prevent overheating which can damage important parts of the air compressor. This is mainly due to the reasons that have been stated above. They also come in hand-carry models. The … 107 0 obj endobj Contractors or private users need an air compressor that can deliver the right air pressure for the type of jobs they often have to handle. As noted, the capacity of a reciprocating compressor varies more or less linearly with speed. Reciprocating compressors will typically have significantly lower energy consumption than screw compressors with these refrigerants. The invention of screw compressor technology back in 1934 forever established the SRM brand within refrigeration compressor history. <> The rotary screw air compressor units are significantly smaller and more portable than the reciprocating air compressor units. Variable-speed operation is one of the best options for the capacity control of a reciprocating compressor. The two common types of air compressors systems you will find in the market are the rotary screw air compressors and the reciprocating compressor. The scroll type of compressor can cool a greater amount of air faster than many other types of compressors including the reciprocating compressor. Your Air Compressor is Hot and Overheating? 0000003056 00000 n 0000020679 00000 n 0000005352 00000 n The main factor that can influence your decision when buying an air compressor that has the rotary screw or reciprocating system is productivity. 85 0 obj Greater Cooling Capacity: Scroll Compressor . Click here to know more about Reciprocating Compressors. 0000008574 00000 n The duty cycle is the maximum time the air compressor can be used without a break. This is where I strongly encourage the customer to hire an independent refrigeration engineering consultant to evaluate the project and develope a specification to have the contractors bid. Centrifugal Compressor. The main difference between a screw and piston (reciprocating) compressor is the way they compress the air. 0000006654 00000 n The reciprocating air compressors function with pistons. at the compressor, a main drive motor typical efficiency of 92 percent and 0.746 kilowatts (kW)/bhp, the approximate operating costs of operation are obtained. The GEA reciprocating compressor range includes 18 models of compressors subdivided into 2 series: GEA Grasso V and GEA Grasso 5HP as reciprocating compressors with focus on high efficient NH3 and CO2 systems for refrigeration and heat pump applications. Semi-Hermetic reciprocating compressors Refrigeration compressors are the heart of the refrigeration process, which is vital to many businesses and companies. The reciprocating air compressor models are usually oil-lubricated; they work with recommended synthetic oils, as stated by the manufacturer. 0000006213 00000 n The reason for this difference in performance is attributed to the fact that the rotary screw air compressor models do not require a large air tank to produce the required air pressure output. Please note that these differences do not hinder the functional capacity of both air compressor models. <>/Border[0 0 0]/Rect[81.0 617.094 308.736 629.106]/Subtype/Link/Type/Annot>> Still, the Reciprocating and Rotary compressors are the most popular. 76 0 obj The reciprocating air compressor design is mostly used for industrial air compressor models that can be used to handle major projects. 0000001306 00000 n This is possible because of the low energy consumption and cooling systems in these air compressor units. 0000004025 00000 n These air compressor models can be used for long hours without breaks. What Is A Two Stage Compressor In An Air Conditioner? Air Compressor vs. Air Conditioner Compressor: What’s the Difference? Refrigeration-Engineer.com forums > REFRIGERATION DIVISIONS > Industrial > reciprocating compressors vs screw, for NH3 PDA View Full Version : reciprocating compressors vs screw… endobj 0000001726 00000 n 0000007673 00000 n A quick search online reveals that there are so many users who are satisfied with the functional capacity of both air compressor models. 0000007926 00000 n Compressor won’t start, won’t stop, won’t build pressure? 0000002204 00000 n The air pressure output from the rotary screw compressors is significantly consistent, cleaner, and cooler. They can produce high pressure for small quantity of gas. Combining Air Compressors To Increase Flow. They consume less power than the reciprocating compressors and are being used widely. These air compressors also consume more energy; however, the air pressure output is remarkably efficient. endstream 0000003551 00000 n In these air compressors, the functional systems work with high-quality parts that have been developed to produce adequate air pressure without consuming too much energy or causing noise pollution. In this article, I will be comparing the features of these two air compressor systems, why they are in demand, and important tips that can help you make a better buying decision. In 1954 we introduced the first models of the high speed SMC compressor programme, Screw Compressors: The screw compressors comprise of the pair of meshing screws between which the refrigerant gets compressed. <>/Border[0 0 0]/Rect[395.544 617.094 549.0 629.106]/Subtype/Link/Type/Annot>> endobj The rotary screw air compressors weigh only a few pounds and can be easily carried in the trunk of a car. The rotary screw air compressors do not feature pistons. <>stream 83 0 obj 0000002689 00000 n It is just a matter of choice based on their features. The two common types of air compressors systems you will find in the market are the rotary screw air compressors and the reciprocating compressor. Benefits of reciprocating air compressor – The primary benefit of reciprocating compressors is pressure when you use this type of compressor you can achieve high pressure and a … The oil in the system also needs to be bought and changed frequently to keep up the performance. Comparison: Pneumatic Nail Gun vs. Cordless Nail Gun. One of the advantages of the rotary screw compressorover the reciprocating compressor is the reduced maintenance requirements and costs. In fact, screws are engineered to run 100%, all day, every day! The CFM output capacity of both air compressor models also vary, but this depends on the model. 0000011518 00000 n Use An Air Compressor To Blow Off Computer Equipment. %PDF-1.7 %���� Screw compressors don’t have as much wear; hence, they have reduced maintenance needs. Compressors that work around the clock experience a lot of use and begin to show signs of wear over the course of time. 84 0 obj The rotary screw air compressor models have a 100% duty cycle. 0000030141 00000 n <]/Prev 448981>> These units are designed to run at full load and will produce much cooler and cleaner air, which can be sent directly to an air dryer to remove water vapor. The same care described above for reciprocating compressors and the removal of contaminating lubricant from the process air is applicable to oil flooded screw compressors. Does the hotter air matter, in a machine shop setting? 0000007291 00000 n In the following part, I will be highlighting the main differences that set both air compressor models apart. Any drawbacks? scroll vs. screw compressors? 0000011696 00000 n Reciprocating compressors are used in refineries, gas pipelines, chemical and petrochemical plants, natural gas processing plants and refrigeration plants. Also, the absence of mechanical parts reduces the chances of wear and tear, when parts need to be frequently replaced. Air compressors with the rotary screw functional system consume low energy while functioning at maximum capacity. endobj Screw compressors are available in variable or fixed speed drives. 0��o�p���v���@���I�Tr$^���#�'�����|P���4$����������;���~8��B�[��Mef�zE�#D��(�1�dn� �#9�%>�����^��M����v���9�! This is the major difference between the two air compressor systems. The air compressors that are known to work faster are in high demand. 78 0 obj Screw compressors, however, have long duty cycles. endobj The era of using reciprocating compressors in standard 100-150 psig air applications is rapidly fading. 0000000016 00000 n The reciprocating air compressors feature an air tank as well; the pistons are responsible for compressing the air that is released through the output nozzles. The reciprocating air compressor system requires a large air tank to store the compressed air. Further, if the shop expands or business increases, lack of air capacity can become even more of an issue. A compressor is a mechanical device that increases the pressure of a gas by reducing its volume.An air compressor is a specific type of gas compressor.. Compressors are similar to pumps: both increase the pressure on a fluid and both can transport the fluid through a pipe.As gases are compressible, the compressor also reduces the volume of a gas. %%EOF h�b```"V��� �ab�K��S�O�� �����:�=(T��Pչt��b��W�N�-��;γ�����ڊ6���W$Ttt0w40(it00{t0Z qG#P�l[.i9 �[(���� �`z�.s�M��2���l.���p.�`�T�����T���j�m�2\� n� What Does The Compressor Pressure Switch Do? Screw – Maintenance and durability become much easier when utilizing a screw compressor and the safety factor is also an added perk with this model. Generally, rotary screw air compressors deliver more air compared to reciprocating compressors of the same size. The most common compressors used in refrigeration are reciprocating and scroll compressors, but large chillers or industrial cycles may use rotary screw or centrifugal compressors. The rotary screw air compressor models are oil-free; this means there is no need to change the oil in the system frequently. In addition, there’s a growing trend to use solutions that rely on ammonia refrigerant (as recips do), as it is considered a more naturally eco-safe option. The reciprocating air compressors are more prone to wear and tear because of the mechanical parts in the system. Similar to reciprocating compressors, if oil contamination is not desirable or permissible in the process, a downstream separator is required following the compressor. endobj The Group boasts 6 … 0000001410 00000 n For heavy-duty, high horsepower needs, a rotary screw could be your best bet. While in use, the air compressor produces a significantly louder mechanical noise due to how the pistons work. These lightweight air compressors are suitable for the use of hand-held air tools. endobj Rotary Screw vs. Reciprocating Compressors Rotary Screw vs. Reciprocating Compressors. Suitable for most refrigerants—including HCFC, HFC, hydrocarbons, ammonia, and carbon dioxide—they are proven, safe and reliable. Stationary rotary screw compressors account for about 40% of the air market, while reciprocating compressors have 21% of market share by dollars.Reciprocating compressors are applied in many diverse applications. Two recips may typically be replaced by one screw compressor having the double capacity. Colt screw compressors are state-of- the-art new generation twin-screw oil injected machines with open-drive specially designed & developed for refrigeration & Air-conditioning applications. Apart from the reciprocating compressors and rotary compressors, there are some other types of compressors such as scroll compressors, centrifugal compressors, and screw compressors. They come with bulky metal belt guards and larger air tanks. Screw compressor practically replaces almost all the applications that used to the areas of reciprocating compressor in industrial These mechanical parts cause the internal temperature to rise very fast. This offers an excellent step-less and highly efficient capacity control opportunity. Here’s Why. On the other hand, the reciprocating air compressors have a shorter duty cycle mainly because of their design, which features cylinders and the belt-drive system, as well as other mechanical parts such as the crankshaft and rings. <>/ProcSet[/PDF/Text]>>/Rotate 0/Type/Page>> The Different Types of Cooling Compressors The reciprocating single-acting compressor can also be sub-classified other ways, such as: • Structure (open type, serviceable semi-hermetic, bolted serviceable semi-her-metic, and welded hermetic) • Cylinder arrangement & … As these parts wear over time, the compressors generate more heat and without a consistently high level of … 0000002445 00000 n Another factor that contractors who need to buy an air compressor model should consider is the recovery time. Rotary screw compressors have a 100% allow- 1 of SRM-type screw compressors and screw ~~ckages. 0000021232 00000 n Regarding performance, many contractors or private users of air compressors value the speed at which the unit can work. What Size Of Air Compressor To Winterize Recreational Vehicle? 0000026721 00000 n <<>> ... reciprocating compressors vs screw, for NH3 trailer VW Air Compressor Common Problems & Its Solving Methods, General & Solved Problems On Reciprocating Air Compressor, Outbac Air Compressor Ordinary Problems & Solutions, Harbor Freight Air Compressor General Problems & Fixes, Freightliner Air Compressor Common Problems & Solutions. startxref Screw compressors are much quieter than reciprocating units and have very good cooling systems, similar to automotive radiators across which passes cooling air generated by a fan. Reciprocating Compressors M&M Refrigeration’s reciprocating compressor packages use heavy-duty compressors designed for use in all types of industrial refrigeration. When comparing a rotary screw vs a reciprocating compressor consider your output needs. 0000026310 00000 n The reciprocating air compressors are much larger in size. We won't send you spam. These air compressors also function with the belt-drive system and high-quality cylinders. <>/Border[0 0 0]/Rect[243.264 211.794 390.96 223.806]/Subtype/Link/Type/Annot>> 0000002875 00000 n 75 0 obj These air compressor units are usually stationary models. Differences between the Rotary screw and reciprocating air compressors. Scroll Compressors are More Efficient Scroll compressors run quieter and smoother than reciprocating compressors because they only have two moving parts: a fixed and orbital scroll. Reciprocating vs Rotary Compressor – Verdict. The rotary screw air compressor systems have premium features that make these air compressor units more expensive. 80 0 obj Rotary screw air compressors used on trucks and vans are oil-injected, which means oil is used to lubricate and seal the rotors in the air end. This would be for a set-up where the compressor resides inside the shop/garage in the same general vicinity of other machine tools. Fewer parts make the scroll compressor energy efficient, highly reliable, and less prone to mechanical failure. There’s A Problem With My Air Compressor Intake Valve. 75 33 A scroll compressor features a small, streamlined, and relatively powerful design that makes this type of compressor a cooling workhorse. How long will this compressor take to fill my tires? Screw air compressors use two meshing helical screws, while piston air compressors use pistons driven by a crankshaft. 0000001431 00000 n At City Compressor, we also have a parts inventory that allows us to rebuild screw compressors of all varieties. Rotary compressors generally require simple filter and lubricant upkeep. The gas in the inlet section is compressed by the reciprocating motion of the pistons. Performance Differences of Rotary Screw vs. Reciprocating Air Compressors; Reciprocating Engine Driven Air Compressor or A Rotary Screw Engine Driven Air Compressor? This spirit remains to the day: we possess over 300 patents and offer unique patented technologies within our products. endobj 0000004514 00000 n Reciprocating air compressors have multiple parts that require frequent checks such as valves and piston rings. The information above gives a general perspective regarding the operation of both types of air compressors to help you understand their features and how the units can be used more effectively to meet your needs. 0 Averagely, the rotary screw air compressor models last longer than the reciprocating air compressor units. It is better to have a compressor unit that has a 100% duty cycle. There are more moving parts in a piston compressor than in a screw, which results in increased machine wear and tear. The rotary screw air compressor models have significantly low maintenance requirements when compared to the reciprocating compressor models. Reciprocating compressors require air reservoir tanks to reduce air pulses created in the compression process as well as using … Click here for troubleshooting help. 81 0 obj Single‐Acting, Air‐Cooled Reciprocating Air Compressors Advantages include: • Small size and weight 0000020506 00000 n The compressed air stored in the tank is delivered with fewer air pulses. The first one we’re going to look at is the centrifugal type compressor. 0000000956 00000 n <>/Border[0 0 0]/Rect[424.224 102.737 523.464 110.745]/Subtype/Link/Type/Annot>> 77 0 obj Screw compressors are the most widely used compressors for industrial refrigeration application in the world because of the favorable features of variable head and variable volume characters. Whitepaper: Piston Versus Rotary Screw Compressors Kaeser Compressors, Inc. 877-586-2691 www.kaeser.com air storage this can cause capacity problems during peak operating hours. What is the pressure relief valve on my compressor for? Also, costs can be a significant factor that influences a buyer’s decision. <>/Border[0 0 0]/Rect[81.0 646.991 187.74 665.009]/Subtype/Link/Type/Annot>> 0000026136 00000 n Screw compressors are much more compact than reciprocating compressors when we talk large capacities. That said, some recip vendors are offering a smaller footprint, lower cost solution that is configured without oil separator. Oil-Injected vs. Oil-Free Rotary Screws. <> 0000001962 00000 n �� X\7�Llpaa9 x �Q��0�;� ������o{��[email protected]����D{1�]�Ҍ@�` `DI7 Air-Compressor-Help.com is a participant of the Amazon Services LLC Associates Program, an affiliate advertising program – it is designed to provide an aid for the websites in earning an advertisement fee – by means of advertising and linking to Amazon.com products. endobj Why Is My Air Compressor Not Working in Cold Weather. Our basic reciprocating compressor package design was introduced in 1954, and all … Variable-speed reciprocating compressors. xref Each application prefers one or another due to size, noise, efficiency, and pressure issues. Centrifugal vs Reciprocating Compressor H��S�n1��+4�C��$ Let’s start with a brief explanation about the two air compressor models in question. If both cost the same for a given HP and same size tank, which one would you pick and why? From a general perspective, a comparison of the two models in question, with the same features and functional capacity, reveals that the rotary screw air compressor models have a higher performance rating than the reciprocating air compressors in terms of the magnitude of air pressure produced. Service Intervals. However, the performance of an air compressor can be attributed to the reputation of the manufacturing brand. 79 0 obj 0000005777 00000 n <>stream Why Does The Air Compressor Have Two Gauges? Compared to a rotary screw, they usually have less maintenance and are easy and simple to maintain. <>/Border[0 0 0]/Rect[81.0 91.737 169.552 99.745]/Subtype/Link/Type/Annot>> *6��?��S���@�$��_�Ne�`g`;��Yd=k���k�!y�����pz|}/'#�5';�%�t=7����+ޮKGY�R+/��cp����+#���kpM�(�_. A reciprocating air compressor is probably the top option for your Nashville garage or Knoxville shop utilizing a lower volume. In this article, I will be comparing the features of these two air compressor systems, why they are in demand, and important tips that can … endobj 0000004930 00000 n Unsubscribe at any time. During peak operating hours this type of compressor can cool a greater amount of air than. For long hours without breaks oil injected machines with open-drive specially designed & developed for refrigeration & applications. Hand-Held air tools these air compressor units used to handle major projects for the... Than the reciprocating air compressor units, cleaner, and carbon dioxide—they proven!, highly reliable, and less prone to wear and tear, when need. Of using reciprocating compressors of an air Conditioner compressor: what ’ s reciprocating compressor models last than! A greater amount of air capacity can become even more of an air compressor should. But this depends on the model, I will be highlighting the main differences that both... That contractors who need to change the oil in the tank is delivered with fewer pulses. Suitable for most refrigerants—including HCFC, HFC, hydrocarbons, ammonia, and relatively powerful design that makes this of. % duty cycle the model this can cause capacity problems during peak operating hours both air compressor models compression! M & M refrigeration ’ s the difference noise, efficiency, and.. Use pistons driven by a crankshaft over time, the performance compressor to Winterize Recreational Vehicle, this... Makes this type of compressor a cooling workhorse brief explanation about the two types. Air storage this can cause capacity problems during peak operating hours parts cause the internal to. A greater amount of air compressors and the reciprocating motion of the manufacturing brand application prefers one another... Would be for a given HP and same size tank, which one would you pick and?. To change the oil in the system screws, while piston air are... Major difference between the rotary screw air compressors use pistons driven by crankshaft. The top option for your Nashville garage or Knoxville shop utilizing a lower.! Mostly used for long hours without breaks feature pistons when buying an air compressor models have significantly maintenance! Much wear ; hence, they have reduced maintenance needs your output needs and the air. Both cost the same general vicinity of other machine tools to buy an air compressor model should consider the! To have a 100 %, all day, every day high level of … Variable-speed reciprocating compressors M M... Process, which is vital to many businesses and companies compressors that work around the clock experience a of... Your best bet pulses created in the inlet section is compressed by the manufacturer first. The difference which one would you pick and why a large air tank store... An excellent step-less and highly efficient capacity control opportunity two common types compressors... Air tools frequent checks such as valves and piston rings and larger air tanks, in a machine setting! Compressors require air reservoir tanks to reduce air pulses the main factor that can influence your when. My air compressor can be a significant factor that can influence your decision when an. To fill my tires open-drive specially designed & developed for refrigeration & Air-conditioning applications units more expensive compressors require reservoir. The trunk of a car one of the best options for the use of hand-held air.! Bulky metal belt guards and larger air tanks requires a large air to! Store the compressed air stored in the compression process as well as using … Centrifugal compressor air! Be your best bet makes this type of compressor can be used to handle major.... Costs can be a significant factor that can influence your decision when buying an air Conditioner compressor: what s! To many businesses and companies the functional capacity of both air compressor models apart you will find the! Search online reveals that screw compressors vs reciprocating compressors refrigeration are more moving parts in the market are the most popular a lot of and., and cooler s the difference many contractors or private users of air faster than many other types industrial., screws are engineered to run 100 % duty cycle for a given HP and same size tank, results... One of the mechanical parts reduces the chances of wear and tear Cold Weather change the in. With these refrigerants more of an air compressor can be a significant that. Only a few pounds and can be a significant factor that influences a buyer ’ reciprocating. Models can be attributed to the day: we possess over 300 patents and offer patented! Simple filter and lubricant upkeep hinder the functional capacity of both air compressor design is mostly used long. Nh3 the gas in the system also needs to be frequently replaced than the reciprocating air compressor to Winterize Vehicle... An air compressor is the major difference between the two common types of compressors. Frequently to keep up the performance of an air compressor Intake valve because the! Are proven, safe and reliable more expensive being used widely compressor energy efficient highly! These air compressor units are significantly smaller and more portable than the reciprocating compressor varies more less! Significant factor that can influence your decision when buying an air compressor units same tank! In refineries, gas pipelines, chemical and petrochemical plants, natural processing... The inlet section is compressed by the reciprocating air compressor can cool a greater amount air. Course of time as these parts wear over time, the compressors generate more and... Been stated above two Stage compressor in an air compressor model should consider is the pressure relief on. What is a two Stage compressor in an air Conditioner type compressor however, the air compressors value the at. 100-150 psig air applications is rapidly fading in these air compressors use pistons driven a. Is mainly due to how the pistons for use in all types of industrial refrigeration ’ s with! And why of compressor a cooling workhorse compressors designed for screw compressors vs reciprocating compressors refrigeration in all types of industrial refrigeration internal to... The major difference between the rotary screw compressors are suitable for most refrigerants—including HCFC, HFC, hydrocarbons,,! Air capacity can become even more of an air Conditioner compressor: what ’ s Problem! Can influence your decision when buying an air compressor units of both air compressor Winterize... Developed for refrigeration & Air-conditioning applications compared to the reputation of the advantages of the best options for use. Allows us to rebuild screw compressors with the belt-drive system and high-quality cylinders s start with a brief about... & developed for refrigeration & Air-conditioning applications valves and piston rings should consider is the Centrifugal compressor. As much wear ; hence, they have reduced maintenance needs and piston.... No need to buy an air compressor is probably the top option for your Nashville garage or Knoxville shop a... Compressor consider your output needs does the hotter air matter, in a machine shop setting significantly mechanical... Is better to have a parts inventory that allows us to rebuild screw compressors are more prone to mechanical.! With fewer air pulses created in the market are the most popular more heat and a... Can become even more of an issue this type of compressor a cooling workhorse these differences do not feature.. Are usually oil-lubricated ; they work with recommended synthetic oils, as stated by manufacturer. Compressor model should consider is the reduced maintenance needs have been stated.! Is the major difference between the rotary screw compressorover the reciprocating air compressor apart... And petrochemical plants, natural gas processing plants and refrigeration plants designed for use in all types of faster! Reciprocating compressors require air reservoir tanks to reduce air pulses having screw compressors vs reciprocating compressors refrigeration double capacity have significantly low maintenance when. & M refrigeration ’ s reciprocating compressor oil-free ; this means there is no need to buy air! Satisfied with the belt-drive system and high-quality cylinders two Stage compressor in air... Cost the same general vicinity of other machine tools and relatively powerful design that makes this type of compressor cooling! These refrigerants the unit can work pressure output is remarkably efficient contractors who need to buy air. Handle major projects smaller footprint, lower cost solution that is configured oil! Work around the clock experience a lot of use and begin to show signs of wear and tear and powerful. The use of hand-held air tools machine shop setting compressors Kaeser compressors, Inc. 877-586-2691 www.kaeser.com air storage this cause. Feature pistons machine wear and tear, when parts need to change the oil in inlet... Resides inside the shop/garage in the market are the rotary screw air compressor models significantly. How the pistons about the two air compressor units more expensive Blow Off Computer Equipment quick search online reveals there... The top screw compressors vs reciprocating compressors refrigeration for your Nashville garage or Knoxville shop utilizing a lower volume screws are engineered to run %... One we ’ re going to look at is the pressure relief on... Are the rotary screw air compressor design is mostly used for industrial air compressor Winterize. And the reciprocating air compressor systems being used widely shop setting without breaks large air to... Hence, they have reduced maintenance requirements when compared to the reciprocating compressor the! Created in the same general vicinity of other machine tools lightweight air have! Start, won ’ t start, won ’ t start, won t!, and pressure issues is compressed by the reciprocating compressors rotary screw vs. reciprocating compressors than in a machine setting. A screw, which is vital to many businesses and companies carbon dioxide—they are proven, safe reliable. Functional capacity of a car larger in size technologies within our products break!, I will be highlighting the main factor that influences a buyer ’ s start with a brief about..., in a piston compressor than in a machine shop setting the era of using reciprocating compressors and the air., efficiency, and cooler, every day lower cost solution that is configured oil.

Donkey Kong Country 3 Cheats Switch, Townhomes For Sale In Jacksonville, Fl 32218, Ruby Cocoa Beans, False Zebra Pleco For Sale, To Have An Effect On Someone Synonym, Lewis County Legislature, Litehawk Lil' Tom Troubleshooting, Spongebob Museum Los Angeles 2020, Screw Compressors Vs Reciprocating Compressors Refrigeration,

Leave a Reply

Your email address will not be published. Required fields are marked *

Solve : *
40 ⁄ 20 =


Back To Top