mud pump working animation supplier

Product Features Power End The power pump shell is the structure of steel plate welding and has been tested with its intensity by authority. The crankshaft is a composed structure of straight shaft and eccentric wheel. Its airproof part of elastic ripple tube has been awarded a patent certificate by the state. The...

Product Features Power End The power pump shell is the structure of steel plate welding and has been tested with its intensity by authority. The crankshaft is a composed structure of straight shaft and eccentric wheel. Its airproof part of elastic ripple tube has been awarded a patent certificate by the state. The...

Product Features Power End The power pump shell is the structure of steel plate welding and has been tested with its intensity by authority. The crankshaft is a composed structure of straight shaft and eccentric wheel. Its airproof part of elastic ripple tube has been awarded a patent certificate by the state. The...

Product Features Power End The power pump shell is the structure of steel plate welding and has been tested with its intensity by authority. The crankshaft is a composed structure of straight shaft and eccentric wheel. Its airproof part of elastic ripple tube has been awarded a patent certificate by the state. The...

Product Features Power End The power pump shell is the structure of steel plate welding and has been tested with its intensity by authority. The crankshaft is a composed structure of straight shaft and eccentric wheel. Its airproof part of elastic ripple tube has been awarded a patent certificate by the state. The...

Product Features Power End The power pump shell is the structure of steel plate welding and has been tested with its intensity by authority. The crankshaft is a composed structure of straight shaft and eccentric wheel. Its airproof part of elastic ripple tube has been awarded a patent certificate by the state. The...

Product Features Power End The power pump shell is the structure of steel plate welding and has been tested with its intensity by authority. The crankshaft is a composed structure of straight shaft and eccentric wheel. Its airproof part of elastic ripple tube has been awarded a patent certificate by the state. The...

Product Features ● Its compact structure, lighter weight, and small size with high efficiency can be matched with kinds of pump devices according to drilling rig`s requirement and different conditions. ●Its durable and compact structure can ensure the smooth operation of pump, and meet the specific requirements of...

Product Features ● Its compact structure, lighter weight, and small size with high efficiency can be matched with kinds of pump devices according to drilling rig`s requirement and different conditions. ●Its durable and compact structure can ensure the smooth operation of pump, and meet the specific requirements of...

Product Features ● Its compact structure, lighter weight, and small size with high efficiency can be matched with kinds of pump devices according to drilling rig`s requirement and different conditions. ●Its durable and compact structure can ensure the smooth operation of pump, and meet the specific requirements of...

Product Features ● Its compact structure, lighter weight, and small size with high efficiency can be matched with kinds of pump devices according to drilling rig`s requirement and different conditions. ●Its durable and compact structure can ensure the smooth operation of pump, and meet the specific requirements of...

Product Features ● Its compact structure, lighter weight, and small size with high efficiency can be matched with kinds of pump devices according to drilling rig`s requirement and different conditions. ●Its durable and compact structure can ensure the smooth operation of pump, and meet the specific requirements of...

Product Features ● Its compact structure, lighter weight, and small size with high efficiency can be matched with kinds of pump devices according to drilling rig`s requirement and different conditions. ●Its durable and compact structure can ensure the smooth operation of pump, and meet the specific requirements of...

Product Features ● Its compact structure, lighter weight, and small size with high efficiency can be matched with kinds of pump devices according to drilling rig`s requirement and different conditions. ●Its durable and compact structure can ensure the smooth operation of pump, and meet the specific requirements of...

Product Features ● Its compact structure, lighter weight, and small size with high efficiency can be matched with kinds of pump devices according to drilling rig`s requirement and different conditions. ●Its durable and compact structure can ensure the smooth operation of pump, and meet the specific requirements of...

What is a mud pump? A mud pump refers to a machine that transports mud or water and other flushing fluid into the borehole during drilling. Types of mud pumps are an important part of drilling equipment. In the commonly used positive circulation drilling, it is to send the surface flushing medium—clear water, mud, or polymer rinsing liquid to the bottom end of the drill bit through a high-pressure hose, faucet, and drill rod center hole under a certain pressure. Cool the drill bit, remove the cut debris and transport it to the surface.

The commonly used mud pump is a piston-type or a plunger type, and the crankshaft of the pump is driven by the power machine, and the crankshaft passes the crosshead to drive the piston or the plunger to reciprocate in the pump cylinder. Under the alternating action of the suction and discharge valves, the purpose of pumping and circulating the flushing liquid is achieved.

During operation, the power machine drives the main shaft and the crank that is fixed thereon by a transmission component such as a belt, a transmission shaft, and a gear. When the crank rotates counterclockwise from the horizontal position from left to right, the piston moves to the power end, the pressure in the liquid cylinder gradually decreases and a vacuum is formed, and the liquid in the suction pool is under the action of the liquid surface pressure, and the suction valve is opened to enter the liquid cylinder. Until the piston moves to the right stop. This working process is called the suction process of the pump.

After the crank completes the above suction process, it continues to rotate counterclockwise. At this time, the piston starts to move toward the hydraulic end (left side in the figure), and the liquid in the cylinder is squeezed. The pressure rises, the suction valve closes, and the discharge valve is closed. Top open, liquid enters the discharge pipe until the piston moves to the left stop. This process is called the pump discharge process. As the power machine continues to operate, the reciprocating pump continuously repeats the process of inhaling and discharging, and the liquid in the suction pool is continuously sent to the bottom of the well through the discharge pipe.

The drilling industry has roots dating back to the Han Dynasty in China. Improvements in rig power and equipment design have allowed for many advances in the way crude oil and natural gas are extracted from the ground. Diesel/electric oil drilling rigs can now drill wells more than 4 miles in depth. Drilling fluid, also called drilling mud, is used to help transfer the dirt or drill cuttings from the action of the drilling bit back to the surface for disposal. Drill cuttings can vary in shape and size depending on the formation or design of the drill bit used in the process.

Watch the video below to see how the EDDY Pump outperforms traditional pumps when it comes to high solids and high viscosity materials commonly found on oil rigs.

The fluid is charged into high-pressure mud pumps which pump the drilling mud down the drill string and out through the bit nozzles cleaning the hole and lubricating the drill bit so the bit can cut efficiently through the formation. The bit is cooled by the fluid and moves up the space between the pipe and the hole which is called the annulus. The fluid imparts a thin, tough layer on the inside of the hole to protect against fluid loss which can cause differential sticking.

The fluid rises through the blowout preventers and down the flowline to the shale shakers. Shale shakers are equipped with fine screens that separate drill cutting particles as fine as 50-74 microns. Table salt is around 100 microns, so these are fine cuttings that are deposited into the half-round or cuttings catch tank. The drilling fluid is further cleaned with the hydro-cyclones and centrifuges and is pumped back to the mixing area of the mud tanks where the process repeats.

The drill cuttings contain a layer of drilling fluid on the surface of the cuttings. As the size of the drill cuttings gets smaller the surface area expands exponentially which can cause rheological property problems with the fluid. The fluid will dehydrate and may become too thick or viscous to pump so solids control and dilution are important to the entire drilling process.

One of the most expensive and troubling issues with drilling operations is the handling, processing, and circulation of drilling mud along with disposing of the unwanted drill cuttings. The drilling cuttings deposited in the half round tank and are typically removed with an excavator that must move the contents of the waste bin or roll-off box. The excavators are usually rented for this duty and the equipment charges can range from $200-300/day. Add in the cost for the day and night manpower and the real cost for a single excavator can be as much as $1800/day.

Using the excavator method explained above, the unloading of 50 barrels of drill cuttings from the half round can take as long as two hours. This task is mostly performed by the solids control technicians. The prime duty for the solids control technicians is to maintain the solids control equipment in good working order. This involves maintenance for the equipment, screen monitoring and changing, centrifuge adjustments, and retort testing to prepare a daily operational summary of the solids control program.

Offshore drilling rigs follow a similar process in which the mud is loaded into empty drums and held on the oil platform. When a certain number of filled drums is met, the drums are then loaded onto barges or vessels which take the drilling mud to the shore to unload and dispose of.

Oil field drilling operations produce a tremendous volume of drill cuttings that need both removal and management. In most cases, the site managers also need to separate the cuttings from the drilling fluids so they can reuse the fluids. Storing the cuttings provides a free source of stable fill material for finished wells, while other companies choose to send them off to specialty landfills. Regardless of the final destination or use for the cuttings, drilling and dredging operations must have the right high solids slurry pumps to move them for transport, storage, or on-site processing. Exploring the differences in the various drilling fluids, cutting complications, and processing options will reveal why the EDDY Pump is the best fit for the job.

The Eddy Pump is designed to move slurry with solid content as high as 70-80 % depending on the material. This is an ideal application for pumping drill cuttings. Drill cuttings from the primary shakers are typically 50% solids and 50% liquids. The Eddy Pump moves these fluids efficiently and because of the large volute chamber and the design of the geometric rotor, there is very little wear on the pump, ensuring long life and greatly reduced maintenance cost for the lifetime of the pump.

plumbed to sweep the bottom of the collection tank and the pump is recessed into a sump allowing for a relatively clean tank when the solids are removed. The Eddy Pump is sized to load a roll-off box in 10-12 minutes. The benefit is cuttings handling is quicker, easier, safer, and allows for pre-planning loading where the labor of the solids control technician is not monopolized by loading cuttings. Here, in the below image, we’re loading 4 waste roll-off bins which will allow the safe removal of cuttings without fear of the half-round catch tank running over.

Mud cleaning systems such as mud shaker pumps and bentonite slurry pumps move the material over screens and through dryers and centrifuges to retrieve even the finest bits of stone and silt. However, the pump operators must still get the raw slurry to the drill cuttings treatment area with a power main pump. Slurry pumps designed around the power of an Eddy current offer the best performance for transferring cuttings throughout a treatment system.

Options vary depending on whether the company plans to handle drill cuttings treatment on-site or transport the materials to a remote landfill or processing facility. If the plan is to deposit the cuttings in a landfill or a long-term storage container, it’s best to invest in a pump capable of depositing the material directly into transport vehicles. Most dredging operations rely on multiple expensive vacuum trucks, secondary pumps, and extra pieces of equipment.

Using an EDDY Pump will allow a project to eliminate the need for excavators/operators to load drill cuttings, substantially lowering both labor and heavy equipment costs. The EDDY Pump also allows a company to eliminate vacuum trucks once used for cleaning the mud system for displacing fluids. Since the pump transfers muds of all types at constant pressure and velocity throughout a system of practically any size, there’s little need for extra equipment for manual transfer or clean up on the dredge site.

The EDDY Pump can fill up a truck in only 10 minutes (compared to an hour) by using a mechanical means such as an excavator. For this reason, most companies can afford one piece of equipment that can replace half a dozen other units.

This application for the Eddy Pump has the potential to revolutionize the drilling industry. Moving the excavator out of the “back yard” (the area behind the rig from the living quarters) will make cuttings handling a breeze. Trucking can be easier scheduled during daylight hours saving on overtime and incidences of fatigued driving. Rig-site forklifts can move the roll-off boxes out of the staging area and into the pump loading area. The operator can save money on excavators rental, damages, and keep the technician operating the solids control equipment.

The EDDY Pump is ideal for drilling mud pump applications and can be connected directly onto the drilling rigs to pump the drilling mud at distances over a mile for disposal. This eliminates the need for costly vacuum trucks and also the manpower needed to mechanically move the drilling mud. The reasons why the EDDY Pump is capable of moving the drilling mud is due to the hydrodynamic principle that the pump creates, which is similar to the EDDY current of a tornado. This tornado motion allows for the higher viscosity and specific gravity pumping ability. This along with the large tolerance between the volute and the rotor allows for large objects like rock cuttings to pass through the pump without obstruction. The large tolerance of the EDDY Pump also enables the pump to last many times longer than centrifugal pumps without the need for extended downtime or replacement parts. The EDDY Pump is the lowest total life cycle pump on the market.

GPM International is a supplier of durable oilfield replacement parts for a wide variety of drilling mud pumps. Inventory products including mud pump fluid end parts, handling tool, etc. All of our products are fully exchangeable with O.E.M. standards.

LLC «Intech GmbH» has been successfully working with different Russian industrial enterprises at the local market for many years having effected over 100 major deliveries of pump equipment to Russian plants.

Today our company is in search of pump equipment producers who consider Russian market attractive and want to boost their sales in the region, as well as expand their field of activities.

We are interested in cooperation with the manufacturers of mud pumps, who are looking for official distributors (representatives) to supply their equipment to the industrial plants in Russia.

Our service engineers are available for supervision and commissioning of pump equipment as well as warranty maintenance in strict compliance with the manufacturer’s recommendations.

Our company is closely cooperating with many engineering institutes of Russia, which gives us an opportunity to include your mud pumps into prospective projects in different industrial fields.

expertise for obtaining local TR CU 010 and TR CU 012 certificates, which will enable your pumps to be used at all the industrial plants of the Customs Union countries (Russia, Kazakhstan, Belarus, Kyrgyzstan).

registration of delivery and subsequent customs clearance of mud pumps, registration of transaction certificates for currency control purposes in Russian banks for payments in foreign currency in accordance with legislation of Russia and Customs Union countries.

Piston membrane pumps are our business. Our only business! We make them Robust & Tough! Josef Emmerich founded the company in 1945 and still today the company is privately owned with a manufacturing facility composed of meticulous craftsmen. Exactly as you would expect from Germany.

Emmerich Manufactured Pump Parts such as Multi-safe Membranes, diaphragms for diaphragm pulsation dampeners, valve seats, sealing rings, etc. are made from a wide variety of materials such as Perbunan (NBR), Neoprene (CR), Hypalon (CSM), Viton (FPM) and Vulkollan (AU).Since 1975, JOSEF EMMERICH PUMPENFABRIK GmbH has had its own in-house production of rubber parts.

Design and manufacture of pumps are by means of state of the art processes and certification to DIN ISO 9001 guaranteed quality. Product development is formed by innovative design and material technology utilizing individual customer requirements.

All manufactured pumps are checked on the processor controlled test stand. Automatically recorded reports of performance are provided to the customer.

The 2,200-hp mud pump for offshore applications is a single-acting reciprocating triplex mud pump designed for high fluid flow rates, even at low operating speeds, and with a long stroke design. These features reduce the number of load reversals in critical components and increase the life of fluid end parts.

The pump’s critical components are strategically placed to make maintenance and inspection far easier and safer. The two-piece, quick-release piston rod lets you remove the piston without disturbing the liner, minimizing downtime when you’re replacing fluid parts.

A Mud Pump may have many changeable parts, such as liner, piston, extension rod, pulsation dampener, valve, clamp, etc. Lake Petro could provide 100% interchangeable parts of many common brands of pump. We offer Liners with Ceramic (Zirconia and Aluminium oxide) and Steel (Metal and Bi-metal) materials. Piston assembly is the important spare parts and expendable parts of oil drilling mud pumps. Mud pump valve assy include valve body, valve seat, valve insert (valve rubber ). Pulsation Dampener is usually installed on the discharge line to reduce the fluctuation of pressure and displacement of the drilling mud pump. Fluid End Module is an important component of the hydraulic pump end of the mud pump.

Mud Pump Pulsation Dampener is usually installed on the discharge line to reduce the fluctuation of pressure and displacement of the drilling mud pump.

Mud Pump Pulsation Dampener is a pneumatic device built into the outflow line of each UUD pump to dampen the pressure fluctuations resulting from the action of the pump. Although presented as a surge tank, this device is really a device that can be tuned to greatly diminish the output pulsations transmitted downstream from the mud pump. Unfortunately, the effectiveness of the pulsation dampener is a function of both output pump pressure and frequency of the pump pulsations.

Drilling consumables such as mud pump systems and their components can drastically increase your uptime while reducing costs and health/safety/environmental (HSE) risks. To support your drilling needs, Forum’s patented P-Quip® mud pump system offers a single-source solution that integrates high-quality fluid end components for maximum longevity and performance.

With more than 20 years of successful operation in severe environments, P-Quip offers a proven track record for the lowest cost of ownership in the industry. As part of our commitment to quality, our mud pump parts use patented Banded Bore™ technology that significantly reduces stress concentrations and leads to longer module life.

Progressive cavity pumps, also known as PC pumps, progressing cavity pumps, eccentric screw pump and mono pumps are a type of rotary positive displacement pump designed for the conveying of liquids and sludges from 1cst to 1Million. They handle not only viscous fluids and solids but also gassing or multiphase liquids containing gas slugs typical during crude oil extraction.

The volume of liquid pumped is proportional to speed providing a linear predictable pumping rate across a range of pressures. This technology delivers one of the highest flow and pressures available from a positive displacement pump being up to 600M³H and 48bar, with efficiency ranging from 55% to 75%. This technology is most suited for fluids more viscous than 5cst.

The design consists of a motor at the drive end which is connected to a gearbox as pc pumps operate at low rpm compared to centrifugal pumps. The output shaft from the gearbox connects to a rotor via a universal pin joint which rotates a metallic rotor within a rubber stator. Stators contain cavities, and the rotor pushes fluids through the cavities in a slow rotating fashion.

A pumps pressure generating ability will depend on the number of cavities within the pump, with high pressure designs often consisting of more than one stator and rotor. Each rotor will typically produce 6 bar enabling pressures up to 48 bar to be achieved through its modular design.

This design of pump is better suited for viscous lubricating fluids, which can contain solids. Short stator life can be experienced with abrasive slurries at which point a peristaltic pump can be a preferred option. Eccentric Screw Pumps viscosity handing is unrivalled, and they are usually specified when there are no other suitable options.

Stator designs consist of two types - equal and non-equal walled. Equal walled stators ensure a lower starting and running torque, lower pulsations and reduced power consumption, high volumetric pumping efficiency, and lower replacement costs. Materials are usually types of rubber being NBR, FKM but not PTFE meaning solvents cannot be handled.

·Oil & Gas – Cutting Transfer, Drilling Mud transfer and recovery, Separator Feed, Crude Oil Transfer, MOL (Main Oil line Pump), Multiphase transfer and injection in remote areas.

Low shear -Ensures gentle handling of the most difficult to pump fluids such as resins, viscous foods, oil and water emulsions without change in consistency to the liquid. They are often use in oily water separators as the design ensures oil droplets remain intact and was rated by SPE (Society of Petroleum Engineers) in Paper SPE18204 as the preferred pump to use for oil droplets which were disturbed the least during handling and a comparison of lobe, vane and screw technology.

Reversible – Units are reversible with reduced output pressure as standard meaning hoses can be emptied, or if blockages are encountered pump can be reversed to assist with clearing. It also enable the pump to be versatile for situations such as tanker loading and offloading.

Wide fluid handling capabilities –Designs can handle viscous liquids, large solids, abrasive materials, fibrous solids and gas slugs without issue making it one of the most versatile pumps available. This design has Unparalleled Viscosity handling viscosities from 1cst to 1Million means there are no comparable pumping technologies.

High Accuracy –Due to flow being directly proportional to pump speed, and due to its cavity design, it enables flows to be very predictable enabling it to be used in metering and dosing applications

Hopper Pump –A pump is fitted with a hopper of various designs, designed for viscous liquids, materials containing high amounts of dry matter, large solids requiring breaking up and materials which plasticise

Multiphase Design -Baseplate mounted unit for multiphase boosting, with accessories allowing pump to handle viscous oil, gas slugs, sand and water, with automatic remote operation.

Bridge Breaker –For the breaking up of large solids within dehydrated sludge. Motorised paddles rotate within the hopper ensuring particles are broken into sizes which can be accommodated by the pump preventing blockages

Motorised wheel – Feeding of liquids with high dry solid content and materials which plasticize into the main pump. When materials such as liquid mortar, resins, mud, blocks of fat, or butter are pumped they can plasticise meaning they change shape rather than break up. To ensure they are fed into the rotor and stator, a motorised wheel ensures materials are broken up when other technologies may mean materials clog.

Liquid injection port –Typically used for the biogas sector, this unit has a separate injection port for accepting liquid manure which is combined with materials in the inlet containing high dry solids content (such as digestate, straw, corn, grass, rye, vegetable and food waste ) ensuring pumpability.

PC Pump curves are different to a centrifugal curve as it is linear demonstrating the units ability to handle liquids of varying viscosities with little impact on pump performance, with the bottom axis being speed rather than flow as flow is proportional to speed. Unit speed is much lower than centrifugal, operating from as little as 50rpm

Not suitable for solventsAll metal parts means solvents can be transferred, although some designs may have bearings within liquids and should be avoidedAll metal parts means solvents can be pumped.

Slurry pumps are mainly used in industrials of mining, metallurgy, dredge, power, coal and other solid slurry transport. Mud pumps are mainly used for drilling, pharmaceutical, brewing, paper, and other industries, which used to transport suspension.

The slurry pump is mainly used in the mining industry, its wear resistance is strong. So It conveys slurry that containing slag, but it can conveys mud. The mud pump is usually made of cast iron, the wear resistance of the pump is low. So the mud pumps often used for conveying mud or slurry containing suspended particles. When the slurry pump working, pump parts are easy to be impacted, wear, and corrosion, etc. Therefore, the liner of the slurry pump uses wear-resistant material, such as high chromium alloy, rubber. The wear-resistant materials can effectively reduce the wear parts of the pump. So most of the slurry pump is a wear-resistant slurry pump in the current market.

The mud pump is the motor driving the piston move through the link mechanism. Then causes the change of the volume of the sealed chamber of the mud pump. and the pressure difference between inside and outside of the pump change. Finally, the process of absorbing water and draining water is complete. When slurry pump working, which is the motor drives the impeller rotation. That is the impeller on the slurry work which increases the kinetic energy of the slurry. At the same time, the slurry flows to the edge of the impeller due to inertia and is discharged from the discharge pipe at a high speed.

The Mud pumps need to be equipped with auxiliary equipment, but slurry pumps not. They often need to use with high-pressure water pump when mud pump working. The high-pressure pump sent the water that larger than the mud pump pressure to the leakproof packing. Then protect the packing. Otherwise, it is easy to make the seal part wear. But the wear-resistant slurry pumps can complete the transportation work independently, which not need to equip other auxiliary equipment.

In a word, the wear-resistant properties of the slurry pumps are stronger, and the ability to convey particles is also stronger. Generally, the capacity of the slurry pump is larger than the mud pump, which is mainly used for coal and metal ore washing. The mud pumps are more suitable for abrasive slurry is not very strong.

1. The two types of pumps are all centrifugal pumps in the working principle. They are machines that increase the energy of solid and liquid mixtures by means of centrifugal force (the rotation of the impeller of the pump). A device that converts electrical energy into kinetic and potential energy of a medium.

Mud hog pump is used to circulate oil drilling mud on a drilling rig at high pressure. Drilling fluid or oil drilling mud is circulated down through the drill string, to help cool, lubricate and clean the drill head, and back through the annulus at high pressures. The drilling mud is also used to suspend and carry out drill cuttings from the drill head as it is brought in and out of the hole.

We can provide more types of mud pumps than other oil well drilling equipment suppliers, and the classification methods are different. There are roughly the following types:

According to the number of times a piston reciprocates in a cylinder to inhale or discharge liquid once, it is divided into sing-acting pump and double-acting pump.

According to different driven method, it is divided into diesel mud pump and electric mud pump.It depends on fuel or energy which is available on around area of drilling rigs.

The mud pump is a reciprocating plunger pump, which converts the rotation of the motor into the reciprocating linear movement of the crosshead and the piston through the crank connecting rod mechanism, and compresses the low-pressure mud into high-pressure mud. During the construction of directional drilling, the high-viscosity, high-density and high-sand-content mud is conveyed into the cave at high pressure to cool the drill bit, wash the hole wall, break the rock, and carry out cuttings when returning from the cave. It is directional One of the most important equipment for drilling construction.

Traditionally, we divide the mud pump into two parts: the hydraulic end and the power end. The power end is used to transmit power and convert movement modes and speeds. Provide suitable power for the liquid end; the liquid end is used to convert mechanical energy into liquid internal energy to transport mud.

The volume of medium discharged by the pump in a unit time is called the theoretical average displacement of the pump, which is referred to as the theoretical displacement of the pump, and is represented by Q.

The energy transferred from the power machine to the pump drive shaft per unit time is called the input power of the pump; the input power when the pump is working and the rated stroke is called the rated power of the pump, expressed in N;

The energy that the liquid increases after the action of the pump per unit time is called the effective power, also called the water power, expressed in Nr, and the efficiency of the pump is the ratio of the effective power to the input power.

Mud pump is an important equipment for directional drilling construction. It transports circulating high-pressure mud into the hole during work, flushes the hole wall, breaks the rock, cools and lubricates the drill bit, and carries the cuttings back out of the hole.

The installation position of the pump should be as low as possible, and the position of the mud pool should be increased as much as possible to improve the suction efficiency of the mud pump.

The inlet end of the suction pipe of the pump should be about 300mm higher than the bottom of the mud tank, and the inner diameter of the suction pipe must be the same.

Firmly support all suction and discharge pipelines so as not to subject them to unnecessary stress. At the same time, it is also to reduce vibration. Never let the pipeline hang on the pump due to insufficient support.

Correct and timely maintenance of the mud pump is a necessary measure to ensure the normal operation of the mud pump and prolong its life. For the use of any pump, this link should be paid attention to.

Observe the working conditions of the cylinder liner and piston. If the leaked mud is found to exceed the normal limit, new cylinder liners and pistons must be replaced.

Check whether the water in the water tank of the spray pump is sufficient and replenish it in time, replace the cooling water when it is contaminated, and clean the water tank at the same time.

It is recommended to conduct a comprehensive inspection of the entire pump every two or three years. Check whether the main bearing, eccentric wheel bearing, crosshead bearing, pinion shaft bearing are worn or damaged. If they cannot be used, they must be replaced with new ones.

If a pump is located beneath the level of the liquid to be pumped, gravity and air pressure ensure that it is constantly filled with the liquid and there can be no ingress of air into the pump or suction line.

In many applications, a pump has to be placed above the level of the liquid, for example, when emptying an underground storage tank. At start-up, there will be air in the suction line and before the pump can discharge the liquid, this air must be evacuated or displaced. Pumps are optimised to move a particular liquid; evacuating a gas is a very different challenge.

Various methods can be used to get around this problem. A secondary pump can be used to evacuate the suction line. A non-return (foot) valve or evacuation tank can be used to stop fluid draining from the suction line when the pump is stopped. However, these solutions all involve extra equipment, piping and processes. Ideally, for these applications, a pump is required that can evacuate air from the suction side at startup before commencing its normal pumping mode. Such a pump is considered to be self-priming.

As a pump evacuates air from the suction side, liquid is forced into the suction line by the pressure of the surrounding air. This process can only continue until the head of liquid balances the local air pressure. With water, for example, it is theoretically possible for a perfectly efficient pump to self-prime to a height of only about 10m from its source. The precise limit is affected by altitude and temperature and will be different for other liquids.

In principle, all positive displacement pumps are self-priming. In particular, this includes rotary gear pumps (internal and external), lobe pumps, vane pumps and diaphragm pumps. A common feature of all positive displacement pumps is the use of close-tolerance parts to prevent fluid returning from the discharge to the suction side. Depending on the effectiveness of these seals created by these close-tolerance parts, a positive displacement pump is capable of venting air from its suction line to some extent. However, under dry running conditions, a pump may overheat and this can cause seal wear and pump failure.

With reciprocating pumps, there is also a danger of cavitation occurring at the point when liquid starts to enter the pump and there is a liquid/air mixture. Under these conditions, vapour bubbles form and expand on the suction side of the pump. Upon reaching the high pressure, discharge side of the pump, the bubbles collapse violently causing vibration and damage to the pumping elements.

For these reasons, it is important to refer to the manufacturer before using a positive displacement pump in an application where it must self-prime and, of necessity, be run dry for any period.

With centrifugal pumps, the pumping action is generated by the transfer of rotational energy from the impeller to the liquid. There are no seals between the suction and discharge sides of the pump. This means that centrifugal pumps are ineffective with gases and are not capable of evacuating air from a suction line when the liquid level is below that of the impeller. In such cases, the pump is said to be air-bound and there is a danger of overheating: generally, pumps rely on the pumped fluid to lubricate and cool the pump’s bearings.

However, with a few modifications to the basic design, a centrifugal pump can be self-priming. The impeller and volute casing is essentially surrounded by a tank so that it can always be immersed in a liquid sufficient to get the pump started and provide the pump with lubrication and cooling – provided the time taken to prime the pump is not excessive.

It is important that a self-priming centrifugal pump’s reservoir is filled correctly with liquid after installation. "Self-priming" in this context means that the pump has the ability to use liquid stored in its housing to generate a vacuum on the suction line. Even a ‘self-priming’ centrifugal pump will not operate when dry. With appropriate bearings and seals, a centrifugal pump can tolerate dry running for a limited time but this is not recommended for extended periods.

In its priming mode, the pump essentially acts as a liquid-ring pump. The rotating impeller generates a vacuum at the impeller’s ‘eye’ which draws air into the pump from the suction line. At the same time, it also creates a cylindrical ring of liquid on the inside of the pump casing. This effectively forms a gas-tight seal, stopping air returning from the discharge line to the suction line. Air bubbles are trapped in the liquid within the impeller’s vanes and transported to the discharge port. There, the air is expelled and the liquid returns under gravity to the reservoir in the pump housing.

Gradually, liquid rises up the suction line as it is evacuated. This process continues until liquid replaces all the air in the suction piping and the pump. At this stage, the normal pumping mode commences, and liquid is discharged.

When the pump is shut off, the design of the priming chamber (normally involving a ‘goose-neck’ on the suction piping) ensures that enough liquid is retained so that the pump can self-prime on the next occasion it is used. If a pump has not been used for a while, it is important to check for losses from the casing due to leaks or evaporation before starting it.

It is possible to use compressed air, instead of a liquid charge, to prime a pump. Compressed air is blown through a jet into a tapered tube to create a vacuum. Air from the pump casing and suction line is drawn in with the compressed air and vented. A check valve seals the discharge line, allowing liquid to enter the pump body. This method has the advantages that the potential for blockages is reduced (because there is no priming chamber) and the pump can be run dry safely.

The ability of a pump to self-prime can be affected by several factors. The discharge line must not be pressurised or blocked. With all types of pump, the suction line must be air-tight. If air continues to be drawn into the pump, the pressure is never reduced and fluid is not drawn up the suction line.

It is also important that the volume of the suction-side pipework is minimised to reduce the priming time. With excessive priming times, there is a danger that the liquid charge will evaporate before the pump is primed. The consequential dry-running may then cause damage to the pump.

In the case of centrifugal pumps, anything that affects the efficiency of the impeller will limit the self-priming ability. If the liquid contains any solids, debris may collect in the recirculation port, impeding the circulation of fluid and the generation of the liquid ring. Debris collecting on the impeller itself will reduce its ability to generate a low pressure region at the eye. Also, as a pump ages and succumbs to wear, the clearances between the impeller and volute case increase and the pump is less able to generate a low pressure zone. Internal clearances can also be affected by incorrect assembly after maintenance.

When pumping water in cold environments, it’s important, if the temperature may fall below freezing, to drain a pump or to provide some form of heating. Damage may occur if water freezes in the pump or pipework.

Self-priming pumps are necessary if a pump has to be located above the level of the liquid to be pumped. A self-priming pump must be capable of evacuating air from the suction line, thereby drawing liquid into the pump. When this has been achieved, the pump can revert to its normal pumping mode.

Most types of positive displacement pumps are self-priming but care must be taken to avoid overheating, seal wear or cavitation during the dry-running, priming phase. Centrifugal pumps can be modified to be self-priming with a surrounding ‘tank’ to retain some of the fluid. Before use, it is crucial that the pump is filled correctly and not allowed to run dry at any stage.