national mud pump repair free sample
We specialize in complete National restoration of internal wear parts Offering thermal spray coatings and specialty welding processes OD & IS Grinding & Machining To OEM Size.
Periodically we"ll inspect for wear, cracks and damage to critical components such as bearings, bull gear and pinion, conrods and crossheads. We"ll check the condition of your seals and other rubber goods and look for oil contamination. We"ll inspect your frame and ensure your pump is set up as per the manufacturer"s recommended tolerances, providing feedback and detailed reporting.
We keep your National mud pumps running in first class condition - providing onsite inspections, repairs and complete overhaul as well as all associated
National parts including the fluid end, power end, stuffing boxes, plungers, seals, bearings, diesel engines, and natural gas engines. We also have blasting and painting facilities as well as a machine shop. We have many years of experience rebuilding mud pumps
Where National overhaul is required we"ll take care of complete disassembly, cleaning and NDT. Repairs will be made to machined components as necessary. Bearings, seals and other components will be replaced in line with our inspections. Motors will be overhauled, lube systems serviced and pulsation dampeners recertified. We"ll also check your fluid ends are in spec and can repair or replace. Your pump is then fully reassembled and commissioned.
When choosing a size and type of mud pump for your drilling project, there are several factors to consider. These would include not only cost and size of pump that best fits your drilling rig, but also the diameter, depth and hole conditions you are drilling through. I know that this sounds like a lot to consider, but if you are set up the right way before the job starts, you will thank me later.
Recommended practice is to maintain a minimum of 100 to 150 feet per minute of uphole velocity for drill cuttings. Larger diameter wells for irrigation, agriculture or municipalities may violate this rule, because it may not be economically feasible to pump this much mud for the job. Uphole velocity is determined by the flow rate of the mud system, diameter of the borehole and the diameter of the drill pipe. There are many tools, including handbooks, rule of thumb, slide rule calculators and now apps on your handheld device, to calculate velocity. It is always good to remember the time it takes to get the cuttings off the bottom of the well. If you are drilling at 200 feet, then a 100-foot-per-minute velocity means that it would take two minutes to get the cuttings out of the hole. This is always a good reminder of what you are drilling through and how long ago it was that you drilled it. Ground conditions and rock formations are ever changing as you go deeper. Wouldn’t it be nice if they all remained the same?
Centrifugal-style mud pumps are very popular in our industry due to their size and weight, as well as flow rate capacity for an affordable price. There are many models and brands out there, and most of them are very good value. How does a centrifugal mud pump work? The rotation of the impeller accelerates the fluid into the volute or diffuser chamber. The added energy from the acceleration increases the velocity and pressure of the fluid. These pumps are known to be very inefficient. This means that it takes more energy to increase the flow and pressure of the fluid when compared to a piston-style pump. However, you have a significant advantage in flow rates from a centrifugal pump versus a piston pump. If you are drilling deeper wells with heavier cuttings, you will be forced at some point to use a piston-style mud pump. They have much higher efficiencies in transferring the input energy into flow and pressure, therefore resulting in much higher pressure capabilities.
Piston-style mud pumps utilize a piston or plunger that travels back and forth in a chamber known as a cylinder. These pumps are also called “positive displacement” pumps because they literally push the fluid forward. This fluid builds up pressure and forces a spring-loaded valve to open and allow the fluid to escape into the discharge piping of the pump and then down the borehole. Since the expansion process is much smaller (almost insignificant) compared to a centrifugal pump, there is much lower energy loss. Plunger-style pumps can develop upwards of 15,000 psi for well treatments and hydraulic fracturing. Centrifugal pumps, in comparison, usually operate below 300 psi. If you are comparing most drilling pumps, centrifugal pumps operate from 60 to 125 psi and piston pumps operate around 150 to 300 psi. There are many exceptions and special applications for drilling, but these numbers should cover 80 percent of all equipment operating out there.
The restriction of putting a piston-style mud pump onto drilling rigs has always been the physical size and weight to provide adequate flow and pressure to your drilling fluid. Because of this, the industry needed a new solution to this age-old issue.
Enter Cory Miller of Centerline Manufacturing, who I recently recommended for recognition by the National Ground Water Association (NGWA) for significant contributions to the industry.
As the senior design engineer for Ingersoll-Rand’s Deephole Drilling Business Unit, I had the distinct pleasure of working with him and incorporating his Centerline Mud Pump into our drilling rig platforms.
In the late ’90s — and perhaps even earlier — Ingersoll-Rand had tried several times to develop a hydraulic-driven mud pump that would last an acceptable life- and duty-cycle for a well drilling contractor. With all of our resources and design wisdom, we were unable to solve this problem. Not only did Miller provide a solution, thus saving the size and weight of a typical gear-driven mud pump, he also provided a new offering — a mono-cylinder mud pump. This double-acting piston pump provided as much mud flow and pressure as a standard 5 X 6 duplex pump with incredible size and weight savings.
The true innovation was providing the well driller a solution for their mud pump requirements that was the right size and weight to integrate into both existing and new drilling rigs. Regardless of drill rig manufacturer and hydraulic system design, Centerline has provided a mud pump integration on hundreds of customer’s drilling rigs. Both mono-cylinder and duplex-cylinder pumps can fit nicely on the deck, across the frame or even be configured for under-deck mounting. This would not be possible with conventional mud pump designs.
The second generation design for the Centerline Mud Pump is expected later this year, and I believe it will be a true game changer for this industry. It also will open up the application to many other industries that require a heavier-duty cycle for a piston pump application.
Many things go into getting the most life out of your mud pump and its components — all important to extend the usage of this vital piece of equipment on an HDD jobsite. Some of the most important key points are covered below.
The most important thing you can do is service your pump, per the manufacturer’s requirements. We get plenty of pumps in the shop for service work that look like they have been abused for years without having basic maintenance, such as regular oil changes. You wouldn’t dream of treating your personal vehicle like that, so why would you treat your pump like that.
Check the oil daily and change the oil regularly. If you find water or drilling mud contamination in the oil, change the oil as soon as possible. Failure to do so will most likely leave you a substantial bill to rebuild the gear end, which could have been avoided if proper maintenance procedures would have been followed. Water in the oil does not allow the oil to perform correctly, which will burn up your gear end. Drilling mud in your gear end will act as a lapping compound and will wear out all of the bearing surfaces in your pump. Either way it will be costly. The main reasons for having water or drilling mud in the gear end of your pump is because your pony rod packing is failing and/or you have let your liners and pistons get severely worn. Indication of this is fluid that should be contained inside the fluid end of your pump is now moving past your piston and spraying into the cradle of the pump, which forces its way past the pony rod packing. Pony rod packing is meant to keep the oil in the gear end and the liner wash fluid out of the gear end. Even with brand new packing, you can have water or drilling fluid enter the gear end if it is sprayed with sufficient force, because a piston or liner is worn out.
There is also usually a valve on the inlet of the spray bar. This valve should be closed enough so that liner wash fluid does not spray all over the top of the pump and other components.
Liner wash fluid can be comprised of different fluids, but we recommend just using clean water. In extremely cold conditions, you can use RV antifreeze. The liner wash or rod wash system is usually a closed loop type of system, consisting of a tank, a small pump and a spray bar. The pump will move fluid from the tank through the spray bar, and onto the inside of the liner to cool the liner, preventing scorching. The fluid will then collect in the bottom of the cradle of the pump and drain back down into the collection tank below the cradle and repeat the cycle. It is important to have clean fluid no matter what fluid you use. If your liners are leaking and the tank is full of drilling fluid, you will not cool the liners properly — which will just make the situation worse. There is also usually a valve on the inlet of the spray bar. This valve should be closed enough so that liner wash fluid does not spray all over the top of the pump and other components. Ensure that the water is spraying inside the liner and that any overspray is not traveling out of the pump onto the ground or onto the pony rod packing where it could be pulled into the gear end. If the fluid is spraying out of the cradle area and falling onto the ground, it won’t be long before your liner wash tank is empty. It only takes a minute without the cooling fluid being sprayed before the liners become scorched. You will then need to replace the pistons and liners, which is an avoidable costly repair. Make a point to check the liner wash fluid level several times a day.
Drilling fluid — whether pumping drilling mud, straight water or some combination of fluid — needs to be clean. Clean meaning free of solids. If you are recycling your fluid, make sure you are using a quality mud recycling system and check the solids content often throughout the day to make sure the system is doing its job. A quality mud system being run correctly should be able to keep your solids content down to one quarter of 1 percent or lower. When filling your mud recycling system, be sure to screen the fluid coming into the tanks. If it is a mud recycling system, simply make sure the fluid is going over the scalping shaker with screens in the shaker. If using some other type of tank, use an inline filter or some other method of filtering. Pumping out of creeks, rivers, lakes and ponds can introduce plenty of solids into your tanks if you are not filtering this fluid. When obtaining water out of a fire hydrant, there can be a lot of sand in the line, so don’t assume it’s clean and ensure it’s filtered before use.
Cavitation is a whole other detailed discussion, but all triplex pumps have a minimum amount of suction pressure that is required to run properly. Make sure this suction pressure is maintained at all times or your pump may cavitate. If you run a pump that is cavitating, it will shorten the life of all fluid end expendables and, in severe cases, can lead to gear end and fluid end destruction. If the pump is experiencing cavitation issues, the problem must be identified and corrected immediately.
The long and the short of it is to use clean drilling fluid and you will extend the life of your pumps expendables and downhole tooling, and keep up with your maintenance on the gear end of your pump. Avoid pump cavitation at all times. Taking a few minutes a day to inspect and maintain your pump can save you downtime and costly repair bills.
Adjust or replace these bearings at first sign of wear. The bearings in the crank end are babbitt lined steel shells, adjustable for wear by removing shims and easily replaced when completely worn. These bearings should be watched closely and adjusted at first signs of looseness.. You will note on series 3400, 3800, 3500, and 3900 pumps, that the shims do not completely fill the outer gap between rod and cap casting, although the connecting rod bolts are tight. This is because the faces of the shell bearings project slightly beyond the faces of the rod and cap castings, and the shims are gripped only between the faces of the bearing halves. Do not try to close this outer gap by tightening the connecting rod bolt as it will put an excessive strain on the bolts.
To check for wear, place a wrench on the top connecting rod bolt and shake the rod parallel to the crankshaft. (The pressure must be relieved from the liquid end of the pump, so that the pump"s mechanism is free to move.) If the rod bearing moves without resistance, the bearing may be too loose and need adjusting. If the bearing does need adjusting, remove shims until you cannot shake the rod, then add .005" shims one at a time until there is little side movement. Be sure to torque rod bolt nuts to proper value for each adjustment. Oil clearance should be checked with Plastigage (available in most parts stores). Wipe crankshaft journal clean of any oil, place a strip of Plastigage on the crankshaft journal and tighten rod cap to the proper torque value. Once tightened, remove rod cap and measure oil clearance with scale on Plastigage package. See oil clearance chart. (NOTE: If you are making this adjustment after having had the crossheads out, be sure that the oil holes in the rod are pointing up. The "up" side is indicated by matching numbers stamped on the cap and rod at the split between them. These numbers should be the same on each rod and should be on the top side of the crankshaft.) Rotate the shaft by hand and if there is any hard drag or tight spots in the bearing, add another 0.005" shim. After this bearing is properly adjusted, loosen bolts a few turns and repeat the above operation on the other bearings. After all bearings have been adjusted.
Torque all connecting rod bolt nuts back to proper value. Again rotate the pump by hand to check for excessive drag and tight spots. If none, the pump should be ready for operation.
If the pump cannot be rotated by hand due to the drive being enclosed, care must-be taken: not to over-tighten the bearings, since they cannot be checked by rotating the pump. When bearings are adjusted by this method, watch carefully for overheating when the pump is put into operation.
It is usually better to have a bearing a little too loose than too tight. A slightly loose bearing will cause very little trouble because of the slow operating speeds of the pump, but a tight bearing will overheat and the babbitt may melt or pull. Normal precautions must be taken to insure cleanliness of parts upon their assembly.
To check for wear, place a wrench on the top connecting rod bolt and shake the rod parallel to the crankshaft. (The pressure must be relieved from the liquid end of the pump so that the pump"s mechanism is free to move.) If the rod bearing moves without resistance, the bearing may be too loose and need adjusting. If the bearing does need adjusting, remove shims until you cannot shake the rod, then add .005" shims one at a time until there is a little side movement. Be sure to torque rod bolt nuts to proper value for each adjustment. (NOTE: If you are making this adjustment after having had the crossheads out, be sure that the oil holes in the rod are pointing up. The "up" side is indicated by matching numbers stamped on the cap and rod at the split between them. These numbers should be the same on each rod and should be on the top side of the crankshaft.) Turn the shaft by hand and if there is any hard drag or tight spots in the bearing, add another .005"" shim. After this bearing is properly adjusted, loosen bolts a few turns and repeat the above operation on the other bearings. After all bearings have been adjusted, torque all connecting rod bolt nuts back to proper amount. Again turn the pump by hand to check for excessive drag and tight spots. If none, the pump should then be ready for operation.
If the pump cannot be rotated by hand due to the drive being enclosed, the bearings may be completely adjusted by shaking the bearing on the shaft as stated above. Care must be taken not to over-tighten the bearings since they cannot be checked by rotating the pump by hand. When bearings are adjusted by this method, they must be watched carefully for overheating when the pump is put into operation.
Alternatively, plastic gauge strips, found in most parts stores may be used to adjust these bearings. It is usually better to have a bearing a little too loose than too tight. A slightly loose bearing will cause very little trouble because of the slow operating speeds of the pump, but a tight bearing will overheat and the babbitt may melt or pull. with experience, an operator can tell by feel when the bearings are properly adjusted. Normal precautions must be taken to insure cleanliness of parts upon their assembly. All wrenches used in adjusting these bearings are standard wrenches.