Positive displacement pumps positive displacement pumps, in contrast, have very little slips, are selfpriming and pump against very high pressures, but their volumetric capacity is low. This subclass covers nonpositivedisplacement pumps for liquids, for elastic fluids, or for liquids and elastic fluids whether rotary or not having pure rotation. If youre seeking these pumps and other processing equipment, you can turn to the experts at arroyo process equipment, inc. Rotating displacement pumps are especially suitable for volumetric dosing tasks and for the conveying of viscous to very highviscosity media. Lobe pump, rotary lobe pump, positive displacement pump. Positive displacement pumps features and a positive. Pumps such as rotary lobe, circumferential piston, progressive cavity, peristaltic, reciprocating plunger and airoperated diaphragm pumps prove to be far more limited in capability in comparison to the axiflow. Linear and rotary positive displacement pumps can provide exceptional accuracy and precision.
Nonpositive displacement pumps definition statement. These pumps generally tend to be larger than equal. Specific gravity specific gravity is used to compare the density of a product to the density of water. Positive displacement pump products for processing operations exceptionally manufactured positive displacement pump products are a necessary part of many different processing operations, particularly when it comes to moving highly pressurized, viscous fluids. Ourindustryleading dragonslayerpowersections allowmudmotorstorunlonger atunprecedentedtemperatures anddepths. What is positive displacement pumps types and advantages. Basic pumping concepts, operating features, benefits and typical applications of the. Durrex pumps is a professional lobe pumps manufacturer, the main products are lobe pump, lobe pumps, rotor pump, rotary lobe pump, rotary lobe pumps, positive displacement pump and so. Lobepro pumps have a low net positive suction head requirement npshr and can selfprime from 15 to 25 ft, depending on site elevation. Positive displacement pumps can be of reciprocating and rotary type. Examples of positive displacement pumps include peristaltic, vane, piston, and gear pumps. The positive displacement pumps can be divided in two main classes. These include a crankshaft, crankcase, connecting rods, crossheads, valves, bearings and fluid head.
Gea hilge novalobe is a extremely reliable rotary lobe pump series that fullfills highest hygienic requirements, based on the proven gea design. Reciprocating pumps include piston, plunger, and diaphragm types. They deliver a nearly constant volume of liquid over a range of discharge pressures. This course, with skills test, makes a great animated study guide for related career skill assessment. Understanding net positive suction head atmospheric pressure until the early 17th century air was largely misunderstood. Definitions and terms density density is the mass of a substance per unit volume. Pump design 1classification of water pumps water pumps can be divided into three types. Pumping element designs include gears, lobes, rotary pistons, vanes, and screws. Listed below are 12 reasons why the hydraulic institute suggests using positive displacement pumps pd pumps. Hayes pump is a factorytrained, stocking distributor for viking pump and provides local support and inventory on positive displacement pumps. Pump school currently focuses on rotary pumping principles. In either case liquid is displaced from the low pressure suction side to. Reciprocating positive displacement pumps, also known as recip pumps, are comprised of many fundamental components that are found in a typical engine.
Positive displacement pumps is a current reference guide for positive displacement pumps for both traditional and stateoftheart testing methods, and serves as a bridge between textbooks and manufacturers literature by providing equipment testing practices based on technical knowhow, practical experience, and academic theory. Fluid handling expert advice on rotary pd pumps select the right positive displacement pump for energyefficient fluid handling. Types of positive displacement pumps are reciprocating, metering, and rotary pumps. Viking pump rotary positive displacement pumps hayes. Centrifugal and positive displacement pumps are widely used in chemical industry for variety of application. Available in medium duty, heavy duty and extreme duty models in cast iron, cast steel and stainless steel. One of the best uses for positive displacement pumps is in industrial pressure washing. Fluid enters from the suction nozzle of the pump and begins filling the lobe cavities. He once said, we live submerged at the bottom of an ocean of the element air. In some casesas in the case of reciprocation pumps npsh is expressed as a pressure increment. Before you make a final decision, its a good idea to check with an engineer who is well versed in positive displacement pumps, but this short slideshare presentation, built in collaboration with viking pumps, can probably get you started in the right direction. The basics of reciprocating positive displacement pumps.
Positive displacement pump is a type of pump used to displace or force oil and petroleum products into pipelines or into various equipment installed in refineries. Nonpositive displacement pumps definition statement this subclassgroup covers. The second is to help the user analyze their pumping requirements, make an appropriate pump selection and size the. G series pumps are versatile enough to handle virtually any pumping application and liquid type. The volume of liquid moved by the pump in one cycle one suction stroke and one discharge stroke is equal to the change in the liquid volume of the cylinder as the piston moves from its farthest left position to its farthest right position. A positive displacement pump has very little fluid slip allowing pumping at high differential pressures with very little flow loss. Positive displacement pumps npsh requirement of these types of pumps are not always expressed in terms of head of liquid. The high water pressure needed to clean heavy manufacturing equipment, processing equipment, and vehicles can only be generated by a positive displacement pump. The operation of this type of pump is holding a fixed volume of fluid that needs to be displaced and then forcing it from the inlet section into the discharge pipe. Positive displacement pumps operate by forcing a fixed volume of fluid from the inlet pressure section of the pump into the discharge zone of the pump. References relevant to classification in this subclass this subclassgroup does not cover. Selection, sizing and performance considerations common to rotary positive displacement pumps. The second is to help the user analyze their pumping requirements, make an appropriate pump selection and size the pump, motor and drive for best performance. Positive displacement rotary gear pumps fischer process.
This online test module on pumps will help you to enrich your knowledge about selection, application and operating knowledge on pumps. Full positive displacement pump training demo content. Positive displacement pumps specifications engineering360. The operating principles of positive displacement pd pumps differ from centrifugal pumps. These pumps are able to handle viscous fluids, which flow at lower speeds and create more resistance, more efficiently than kinetic dynamic pumps. The pumps manufactured by us include progressive cavity pumps, twin screw pumps, triple screw pumps, gear pumps, lobe pumps, vane pumps, shuttle block pumps as well as thermic fluid pumps. Non positive displacement pumps for liquids, for elastic. An engine typically converts energy stored in fuel to mechanical power through combustion.
With this complete range of pumps, pumpsquare offers to the engineers, suppliers, oems and users a single source of supply for their pump requirements. Non positive displacement pump non positive displacement pump are also known as hydro dynamic pump. Types positive displacement pumps a lobe pump a positive displacement pump causes a fluid to move by trapping a fixed amount of it then forcing displacing that trapped volume into the discharge. Positive displacement pumps principle of operation. Types of positivedisplacement pumps are reciprocating, metering, and rotary pumps. Does cavitation takes place in positive displacement pumps. Jul 21, 2016 if youve been charged with selecting a positive displacement pump for your process, you might be overwhelmed with the options available. A rotary pump is a positive displacement pump consisting of a chamber containing gears, cams, screws, vanes, plungers, or similar elements actuated by relative rotation of the driveshaft to casing, and which has no separate inlet and outlet valves. Learn positive displacement pump types, theory, more. Because fluid properties affect positive displacement pumps differently than centrifugal pumps, its critical to understand the interaction between the pump and the fluid and how the operation of positive displacement pumps differs from centrifugal pumps. A pump is a device that moves fluids liquids or gases, or sometimes slurries, by mechanical. Evangelista torricelli, an italian scientist, was one of the first to discover that air, like water, has weight. Jan 20, 2018 in this video, we will describe the different types of positive displacement rotary pumps.
This type of pump delivers a near constant flow rate regardless of the system pressure. This course, with skills test, makes a great animated study guide for related career skill assessment this course covers many pump types and related information in the industry. The positive displacement principle applies whether the pump is a. In this video, we will describe the different types of positive displacement rotary pumps. Both viking pump and hayes pumps engineering expertise in rotary positive displacement gear. Positive displacement pumps positive displacement pumps, which lift a given volume for each cycle of operation, can be divided into two main classes, reciprocating and rotary. Viking pump rotary positive displacement pumps hayes pump. A positive displacement pump is usually more efficient resulting in less driving power and less heat transferred into the fluid.
As with many positive displacement pumps, the tuthill external gear pumps. By definition, positivedisplacement pd pumps displace a known quantity of liquid with each revolution of the pumping elements. Positive displacement pumps with positive displacement pumps the flow rate q is linear dependent on the pump speed n. Positive displacement pumps use a mechanical force such as gears, bladders, pistons, plungers or diaphragms to. Positive displacement pumps are another category of pumps. On a test stand the flow rate is determined for various speeds and total head i.
The delivered capacity is nearly constant throughout the discharge pressure range. A positive displacement pump has an expanding cavity on the suction side of the pump and a decreasing cavity on the discharge side. Nov 22, 2016 centrifugal and positive displacement pumps are widely used in chemical industry for variety of application. Positive displacement pumps pumps using pistons or other mechanical members to displace a working fluid in a working chamber, the dynamic effect on the fluid being of minor importance 2. The operation of this type of pump is holding a fixed volume of fluid that needs to be displaced and then forcing it. Lobepro pumps provides a smooth, steady pumping action which delivers significantly less pulsation than other positive displacement pumps, also avoiding the shearing of sensitive fluids and emulsification of hydrocarbons. Find positive displacement pumps on globalspec by specifications. What is the difference between the positive and non. This is done by trapping liquid between the pumping elements and a stationary casing. Select the right positive displacement pump for energyefficient fluid handling. Positive displacement pumps are a category of pumps designed to move fluid at a steady rate through a system.
Pumps operate by some mechanism typically reciprocating or rotary, and consume energy to perform mechanical work by moving the fluid. The volume is a constant given each cycle of operation. Positive displacement pumps are generally used for specialist applications such as for pumping viscous liquids or liquids that contain suspended or fragile solids. Non positive displacement pumps definition statement this subclassgroup covers. Centrifugal pumps and propeller pumps are the best example. About positive displacement pumps hydraulic institute. Linear or rotary displacement pump, which is right for you. A positive displacement pump has an expanding cavity on the suction side and a decreasing cavity on the discharge side. For rotary gear or other type of positive displacement pumps npsh is only a. If youve been charged with selecting a positive displacement pump for your process, you might be overwhelmed with the options available. Rotary pump family tree positive displacement pd pumps are divided into two broad classifications, reciprocating and rotary figure 1. A self contained floor standing mobile unit with full instrumentation consisting of an oil reservoir. The axiflow pump offers a wide range of benefits over all other pd pumps.
Positivedisplacement pumps operate by forcing a fixed volume of fluid from the inlet pressure section of the pump into the discharge zone of the pump. Both viking pump and hayes pumps engineering expertise in rotary positive displacement gear pump solutions is unparalleled in the industry. A positive displacement pump in which rotary motion carries the liquid from the pumps inlet to its outlet. When using a positive displacement pump care needs to be taken to. Positive displacement pumps have a very close clearance between rotating and stationary parts and hence are selfpriming. Dec 07, 20 positive displacement pumps principle of operation. Non positive displacement pumps for liquids, for elastic fluids, or for liquids and elastic fluids, whether rotary or not having pure rotation. These pumps are typically not capable of such a high flow rate as say, a centifrugal pump, but they are capable of producing much higher pressures. Its time to take pump quiz to test your knowledge on pumps now. Pumps are the important equipment in chemical process industries.
In either case liquid is displaced from the low pressure suction side to the high pressure discharge side. Rotary pumps by definition, positivedisplacement pd pumps displace a known quantity of liquid with each revolution of the pumping elements. The above picture is just a screen shot, click to see demo. We will discuss here the difference between positive and nonpositive displacement pump.
Liquid flows into the pumps as the cavity on the suction side expands and the liquid flows out of the discharge as the cavity collapses. This course covers many pump types and related information in the industry. Different types of pumps positive displacement pumps. Pumps reliability expert advice on rotary pd pumps. Gear, lobe, vane, peristaltic, screw, progressive cavity and after we finish the. The gormanrupp g series line of positive displacement rotary gear pumps is designed to provide performance no other gear pumps can match.
The nearly vertical pressure stiff performance curve of rotary positive displacement pd pumps stems from a basic principle. Figure 1 by definition, pd pumps displace a known quantity of liquid with each revolution of the pumping elements i. As a volumetric fluid handling technology, rotary pd pumps create flow and are insensitive to system pressure changes. Positive displacement pumps selection guide engineering360. Hayes pump distributes viking pumps broad line of products from industrial pumps, to parts and accessories, including strainers, reducers, units, and maintenance kits.