mud pump flush procedure free sample

I was recently asked about a procedure for flushing hydraulic systems in order to change from one type of fluid to another. Among the ideas mentioned involved using brake cleaner, diesel fuel or some type of acid cleaning.

For these reasons, it"s important to understand flushing properly or to use an experienced oil flushing service provider who can help you get the job done right.

In his article for Machinery Lubrication titled “Cleaning and Flushing Basics for Hydraulic Systems and Similar Machines,” Tom Odden outlines the procedure for thoroughly cleaning a hydraulic system. This would be the only “one-size-fits-all” solution and an example of best practices. It involves mechanical and chemical cleaning of both the components and the system.

of lubrication professionals say mechanical cleaning is the flushing method used most frequently at their plant, according to a recent poll at machinerylubrication.com

Flush the system with a lower viscosity fluid that is similar to the fluid to be used. A Reynolds number between 2,000 and 4,000 should be selected to achieve enough turbulence to remove particles from the lines. Stroke valves frequently to ensure they are thoroughly flushed. The fluid should be filtered and the flushing should continue until reaching one level beyond the system’s target cleanliness levels. For example, if the target is ISO 15/13/11, continue to flush the system until ISO 14/12/10 is reached.

Fill the system to approximately 75 percent with the fluid to be used. Bleed/vent the pump. If the pump has a pressure relief or bypass, it should be wide open. Run the pump for 15 seconds, then stop and let it sit for 45 seconds. Repeat this procedure a few times to prime the pump.

Run the pump for a minute with the bypass or pressure relief open. Stop the pump and let it sit for a minute. Close the bypass and permit the pump to operate loaded for no more than five minutes. Allow the relief valve to lift to confirm that it is flushed as well. Do not operate the actuators at this time. Stop the pump and let the system sit for about five minutes.

Start the pump and operate the actuators one at a time, allowing fluid to return to the reservoir before moving to the next actuator. After operating the final actuator, shut down the system. Keep an eye on the fluid level in the reservoir. If the level drops below 25 percent, add fluid and fill to 50 percent.

Refill the reservoir to 75 percent and run the system in five-minute intervals. At each shutdown, bleed the air from the system. Pay close attention to the system sounds to determine if the pump is cavitating.

Run the system for 30 minutes to bring it to normal operating temperature. Shut down the system and replace the filters. Inspect the reservoir for obvious signs of cross-contamination. If any indication of cross-contamination is present, drain and flush the system again.

There are a lot of different ways to flush out a machine. You want to match the flushing method to the flushing condition. Following are common tactics for accomplishing this:

High Turbulence, High Fluid Velocity, Low Oil Viscosity — Flushing is enhanced by high turbulence flushing conditions by lower flush oil viscosity and increasing oil flow rates. This usually requires specialized equipment to achieve proper turbulent flow. Talk to a service provideryou trust who offers high-velocity oil flushing services.

High Flush Oil Temperature — This reduces viscosity, increases turbulence and increases oil solvency. Temperatures in the range of 175 to 195 degrees F are generally targeted.

Cycling Flush Oil Temperature— Using heat exchangers and coolers to change temperature during flushing across a 100 degree F range helps dislodge crusty surface deposits.

Wand Flush Tool — Used for wet sumps, gearboxes and reservoirs with access hatches and clean-out ports. A wand on the end of a flushing hose is used to direct high-velocity oil flow to loosen deposits or for picking up bottom sediment.

Solvent/Detergent Flush Fluid — Various solvents and detergents have been used with different degrees of success, including mineral spirits, diesel fuel, motor oils and detergent/dispersant packages.

Some adherent machine deposits require tactics that are more aggressive than a high-velocity flush, so you must match the flushing tactic and strategy to the problem you are trying to resolve with the flush. Once you understand the problem within the machine that needs to be cleaned, you can then select the appropriate flushing tactic to remedy it. This issue was described in Jim Fitch’s three-part series on flushing for Machinery Lubrication, which can be read at www.machinerylubrication.com/Read/609/oil-flush, www.machinerylubrication.com/Read/634/oil-flushing-tactics and www.machinerylubrication.com/Read/657/flushing-oil.

At this point, it should be obvious that a fluid changeout is not just a drain-and-fill operation. Care must be taken to confirm that the system is as clean as possible prior to introducing the new fluid. Most changeover procedures suggest that some of the old fluid will need to be either drained off the bottom or skimmed off the top of the reservoir after a period of time.

Just because the changeover has been completed does not mean that you are “out of the woods.” Your system will need to be closely monitored for a while to make certain that the flushing was thorough. Taking the time to verify that the system is fully flushed and purged of the old fluid prior to introducing the new fluid will go a long way toward ensuring a healthier hydraulic system.

Cavitation is an undesirable condition that reduces pump efficiency and leads to excessive wear and damage to pump components. Factors that can contribute to cavitation, such as fluid velocity and pressure, can sometimes be attributed to an inadequate mud system design and/or the diminishing performance of the mud pump’s feed system.

When a mud pump has entered full cavitation, rig crews and field service technicians will see the equipment shaking and hear the pump “knocking,” which typically sounds like marbles and stones being thrown around inside the equipment. However, the process of cavitation starts long before audible signs reveal themselves – hence the name “the silent killer.”

Mild cavitation begins to occur when the mud pump is starved for fluid. While the pump itself may not be making noise, damage is still being done to the internal components of the fluid end. In the early stages, cavitation can damage a pump’s module, piston and valve assembly.

The imperceptible but intense shock waves generated by cavitation travel directly from the fluid end to the pump’s power end, causing premature vibrational damage to the crosshead slides. The vibrations are then passed onto the shaft, bull gear and into the main bearings.

If not corrected, the vibrations caused by cavitation will work their way directly to critical power end components, which will result in the premature failure of the mud pump. A busted mud pump means expensive downtime and repair costs.

To stop cavitation before it starts, install and tune high-speed pressure sensors on the mud suction line set to sound an alarm if the pressure falls below 30 psi.

Although the pump may not be knocking loudly when cavitation first presents, regular inspections by a properly trained field technician may be able to detect moderate vibrations and slight knocking sounds.

Gardner Denver offers Pump University, a mobile classroom that travels to facilities and/or drilling rigs and trains rig crews on best practices for pumping equipment maintenance.

Severe cavitation will drastically decrease module life and will eventually lead to catastrophic pump failure. Along with downtime and repair costs, the failure of the drilling pump can also cause damage to the suction and discharge piping.

When a mud pump has entered full cavitation, rig crews and field service technicians will see the equipment shaking and hear the pump ‘knocking’… However, the process of cavitation starts long before audible signs reveal themselves – hence the name ‘the silent killer.’In 2017, a leading North American drilling contractor was encountering chronic mud system issues on multiple rigs. The contractor engaged in more than 25 premature module washes in one year and suffered a major power-end failure.

Gardner Denver’s engineering team spent time on the contractor’s rigs, observing the pumps during operation and surveying the mud system’s design and configuration.

The engineering team discovered that the suction systems were undersized, feed lines were too small and there was no dampening on the suction side of the pump.

Following the implementation of these recommendations, the contractor saw significant performance improvements from the drilling pumps. Consumables life was extended significantly, and module washes were reduced by nearly 85%.

Although pump age does not affect its susceptibility to cavitation, the age of the rig can. An older rig’s mud systems may not be equipped for the way pumps are run today – at maximum horsepower.

It may be impractical to flush system piping during drilling operations. However, strainer screens should be checked daily to remove any debris or other flow restrictions.

There are many different ways to drill a domestic water well. One is what we call the “mud rotary” method. Whether or not this is the desired and/or best method for drilling your well is something more fully explained in this brief summary.

One advantage of drilling with compressed air is that it can tell you when you have encountered groundwater and gives you an indication how much water the borehole is producing. When drilling with water using the mud rotary method, the driller must rely on his interpretation of the borehole cuttings and any changes he can observe in the recirculating fluid. Mud rotary drillers can also use borehole geophysical tools to interpret which zones might be productive enough for your water well.

The mud rotary well drilling method is considered a closed-loop system. That is, the mud is cleaned of its cuttings and then is recirculated back down the borehole. Referring to this drilling method as “mud” is a misnomer, but it is one that has stuck with the industry for many years and most people understand what the term actually means.

The water is carefully mixed with a product that should not be called mud because it is a highly refined and formulated clay product—bentonite. It is added, mixed, and carefully monitored throughout the well drilling process.

The purpose of using a bentonite additive to the water is to form a thin film on the walls of the borehole to seal it and prevent water losses while drilling. This film also helps support the borehole wall from sluffing or caving in because of the hydraulic pressure of the bentonite mixture pressing against it. The objective of the fluid mixture is to carry cuttings from the bottom of the borehole up to the surface, where they drop out or are filtered out of the fluid, so it can be pumped back down the borehole again.

When using the mud rotary method, the driller must have a sump, a tank, or a small pond to hold a few thousand gallons of recirculating fluid. If they can’t dig sumps or small ponds, they must have a mud processing piece of equipment that mechanically screens and removes the sands and gravels from the mixture. This device is called a “shale shaker.”

The driller does not want to pump fine sand through the pump and back down the borehole. To avoid that, the shale shaker uses vibrating screens of various sizes and desanding cones to drop the sand out of the fluid as it flows through the shaker—so that the fluid can be used again.

Some drillers use compressed air to blow off the well, starting at the first screened interval and slowly working their way to the bottom—blowing off all the water standing above the drill pipe and allowing it to recover, and repeating this until the water blown from the well is free of sand and relatively clean. If after repeated cycles of airlift pumping and recovery the driller cannot find any sand in the water, it is time to install a well development pump.

Additional development of the well can be done with a development pump that may be of a higher capacity than what the final installation pump will be. Just as with cycles of airlift pumping of the well, the development pump will be cycled at different flow rates until the maximum capacity of the well can be determined. If the development pump can be operated briefly at a flow rate 50% greater than the permanent pump, the well should not pump sand.

Mud rotary well drillers for decades have found ways to make this particular system work to drill and construct domestic water wells. In some areas, it’s the ideal method to use because of the geologic formations there, while other areas of the country favor air rotary methods.

To learn more about the difference between mud rotary drilling and air rotary drilling, click the video below. The video is part of our “NGWA: Industry Connected” YouTube series:

Flushing is the process of using the scouring action of moving water to help rid a water supply of contaminants, and it is an essential part of the disinfection process. Flushing normally takes place several times during the disinfection process.

Install the pump as close to the bottom of the well as possible during the flushing stage. For fractured or very porous rock formations, it may be necessary to move the pump up and down the length of the exposed borehole to assure water movement into the entire well bore.

Generally, the longer the flushing time, the better. A suggested minimum is to pump until at least 20 casing volumes have discharged from the well. For example: A 100-foot deep 5-inch well has a casing volume of 100 gallons. A minimum of 2,000 gallons of water (20 casing volumes times 100 gallons) should be flushed from the well.

In some cases, flushing without further chlorination has been effective in correcting contamination problems. Some local health departments have found that allowing water to discharge from a garden hose continuously for a period of at least 24 hours or more has corrected the contamination problem without the need to treat with chlorine. The hose is discharged into a roadside ditch or into the yard away from any on-site sewage disposal system. Open the sill cock valve all the way during the flushing stage.

A water sample should be collected from the water supply after the flushing period to determine if the flushing process has corrected the bacterial contamination problem. If coliform bacteria are not present in the water sample analyzed, the flushing may have successfully disinfected the water supply. However, a second water sample is recommended approximately one week later to verify that the bacterial contamination problem has been corrected.

The initial discharge of water from a recently chlorinated well may contain elevated levels of chlorine and chlorination byproducts. Do not run the water into a surface water body. Avoid flushing for long periods if discharge water will flow onto neighboring property or roadways, or otherwise create a nuisance condition.

The Liberty Process LL8 Progressive Cavity Pump is ideal for abrasive pumping applications such as drilling fluids with sand and grit common in fracking operations. As a Mud Pump, the LL8 Series is a popular model on many mobile pumping rigs in use today. Replacement mud pump parts are available as well from our stock and work on other popular manufacturers models.

The Liberty LL8 is a standard flanged pump design manufactured with cast iron or 316 stainless steel pump casings designed in 1, 2, and 3 stages for 75, 150 and 225 psi discharge pressures and a flow rate of 18 up to 100 GPM.

The LL8 is a modular design with simple hardened pinned joint drive assembly. LL8 Rotors are typically hardened tool steel or 316 stainless steel with a hard chrome plating for long life in abrasive pumping applications.

All other wetted parts are either carbon steel or 316 stainless steel. Stators are available in many elastomer materials such as Buna Nitrile, Natural Rubber, EPDM and Viton. The standard seal design is a set of gland packing with a lantern ring set and flush connections. Mechanical seal options for this progressive cavity pump are readily available.

The LL8 represents one of the most popular progressive cavity pumps available for the transport of drilling mud with easily replaceable in-stock parts.