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• Rodolfo Castro

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Triplex Pump Training Module

2.3

PAGE : 31 December 1999

Fluid End There are 5 different Dowell Fluid Ends available for the PG Series Power End. The most common ones are the 'G', 'L' and 'H' ends. The other fluid ends ('R' and 'S') are for special applications requiring extremely high pressures such as stimulation work.

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Triplex Pump Training Module

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They are machined from forged AISI 4340 steel or better. The fluid ends with the higher-pressure ratings are usually Autofrettaged* to lengthen the fluid end's life. Autofretagging is similar to the process used in making artillery gun barrels - this improves the metal's resistance to fatigue. Fluid End Specifications MODEL

PLUNGER SIZE (INCHES)

MAX PRESSURE (PSI)

MAX FLOW RATE* (BPM)

BBL/REV PINION

THO ('H') TLO ('L') TGO ('G') TRO ('R')

5 4½ 3¾ 3

5,500 7,000 10,000 15,000

10.3 8.4 5.8 3.7

0.00681 0.00553 0.00384 0.00245

Note: It is recommended that you use both discharge ports for flow rates over 8.2 BPM due to the erosion of the discharge port, bushing and also the discharge manifold. Maximum Fluid End pressure limitations are based on Power End Maximum Rod Load rather than the pressure limitations of the fluid end. *The Maximum flow rate of a Triplex Pump is calculated on the basis of 97% volumetric efficiency.

* Auto frettaging is a heat treatment process where the material is heattreated and stress relieved simultaneously at high pressure.

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Triplex Pump Training Module

PAGE : 33 December 1999

The entire assembly of the PG05 Series (steel frame) Triplex Pump, including chaincase, power end and fluid end weighs 5,250 lbs. (2.4 tones). The PG05 power end is used on offshore skid units like the CPS 362 where unit weight is not a critical factor. It is also used in corrosive environments such as offshore areas where the PG03 power end, which has a magnesium frame, would be prone to severe corrosion. The PG03 power end is used on CPT 372, CPT 462 and CPS 310 Heli-Unit because weight is an important design factor.

CPS 362

CPT 372

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Triplex Pump Training Module 3.0

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Lubrication System It is obvious that a pump capable of outpouring 300 HHP (Hydraulic Horsepower) power requires considerable moving parts which must be kept lubricated in order to function efficiently at a reasonable temperature. It must also be dependable, with an acceptable operating life. Each component - the Chain Case, Power End and the Fluid End - has its own lubrication system to satisfy its individual requirements.

3.1

Chain Case Method of lubrication Lubricant (oil). (grease) Capacity Level

Splash (chains and sprockets) Grease (bearings and seals) SAE 40 WT moly-based 0.5-1 gal Dipstick (full mark, pump stopped)

Each chain case is equipped with either a sight glass or a dipstick for indicating the oil level in the case. The oil level indicator should be centerlined with the bottom of the input shaft.

Note: When checking the oil level, always remove the dipstick and allow the oil level to settle, then check the correct level by re-inserting and removing the dipstick. Too much as well as too little oil in the Chain Case can actually cause it to overheat. When a chain case is overheated, the bearing grease seals are usually damaged first. If overheating continues, severe damage can result to the bearings and chain as the overheated oil breaks down chemically, losing its viscosity and also its lubricating and cooling properties. The bearing grease is also affected by the high temperature, resulting in the grease not lubricating the bearings correctly, thus producing more heat.

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Triplex Pump Training Module 3.2

PAGE : 35 December 1999

PG Series Power end Method of lubrication Flow rate Oil pressure Lubricant

Force Feed 15- 20 gpm 25-45 psi SAE 80w-90 WT Gear Oil SAE 80 WT

Capacity

Level indicator Maximum Oil temperature

(above 32 deg F)

(below 32 deg F)

17 gallons (This is only the sump volume and does not include filter and hose capacity) Dipstick or 1/2 " below main bearing caps 160 deg F (70 deg C)

The Power End frame is actually the reservoir for the Power End lubricant. It should be noted that when check the oil level always remove the dipstick and allow air to escape from the tube then replace the dipstick and check for correct level.

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Triplex Pump Training Module

PAGE : 36 December 1999

Oil is taken from the power end sump by a mechanically or hydraulically driven oil pump, and returned under pressure to the power end through a filter. After the filter, it flows to a cross fitting in the line. At the cross, the lubricating oil is directed to: 1.

Both ends of the main shaft, and to each of the crossheads.

2.

A pressure relief valves is used to maintain a constant flow and maximum system pressure.

Since pressure in any hydraulic system is a result of resistance and this is a hydraulic system. Also since the flow rate will vary with engine RPM’s. The pump is sized that it will still maintain adaquate oil pressure at low engine speeds, not idle, but as the components wear lower oil pressure will result. This can create problems when the powerend is working at very low rate’s and high discharge pressures, the engine is at to low of RPM’s to create enough oil pressure to maintain a good film of oil on the eccentric bearings and the rod load is high, the two combined create catastraphic powerend failures. This is just one reason it is always important to watch and maintain powerend oil pressure. Proper sizing of the fluid end can prevent these type of failures. There are two different styles of powerend oil filters and arrangements used, one being internal by-pass (parker brand is the new style) the other being external by-pass (old style). A by-pass around the oil filter ensures continued flow of oil in the event the filter becomes plugged. This is controlled by the by-pass relief valve. On the old style it is usually mounted directly to the filter and has a hose, which directs any by-pass flow to the downstream side of the filter. On the new style the by-pass is internal of the filter housing and has a pre-determined differential setting. The new style filters have an indicator which clearly indicates when and if the filter is by-passing. Color coded- green being good and Red being Bypassing. This indicator only works when the oil is flowing through it and should be checked during the job and recorded on the STEM I report. The oil pressure is controlled by a relief valve in the system usually mounted directly to the bottom of the power end frame. A pressure gauge mounted on the control panel or directly on the power end lube oil circuit lets the operator monitor the system oil pressure on each pump. The oil must be kept clean at all times. A milky appearance usually indicates water contamination. (Refer to section on Care & Maintenance of the Power End and also the Trouble Shooting Guide in the Appendix to help identify possible problems and correct them.

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Triplex Pump Training Module

December 1999

Brown & Sharpe Webster or Tyrone Pump

It should be noted that there are oil seals inside the either main shaft bearing cap of the power end. When these seals wear the result will be lower oil pressure, primarily seen on the gauge, because the gauge is tied in directly to the cap.

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Triplex Pump Training Module

PAGE : 38 December 1999

Below are pictures of a pressure relief valve. These valves are very easy to adjust the setting. Simple remove the large cap turning the adjustment screw clockwise will increase pressure, turning it counter clockwise will reduce the pressure setting. Always consult your maintenance department before tampering with any adjustments.

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Triplex Pump Training Module

PAGE : 39 December 1999

Below are pictures of a power end lube pump on a CAT 3176 Deck engine of a CPT 372. This is a vane type hydraulic pump. This pump is directly mounted to the gear train on the engine via a splined input shaft. If the shaft seal were to leak on this type mounting, typically the result would be a noticeable increase in the engine oil level.

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Triplex Pump Training Module

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PAGE : 40 December 1999

Triplex Pump Training Module

PAGE : 41 December 1999

Here are pictures of a Tyrone Brand power end lube pump. This is a gear type hydraulic pump. When these pumps are mounted on one of the rear auxiliary drive gears of a Detroit Diesel Engine. It must be mounted using an angle drive adapter, which reduce the input Rpm’s. The auxiliary drive on these engines rotates at twice the engine Rpm’s. The Tyrone pump uses a straight input shaft, special care must be taken when installing the tapered drive adapter on this style pump. The spacing of the drive gear is critical so the gear will set correctly in the center of the driving gear of the angle drive. Failure to do so can result in loose of oil pressure to the power end in critical situations. Special instructions are located in the Maintenance Bulletins and in the Maintenance CD Set. Again if the seal were to leak on this style mounting it would increase the oil level in the engine, this would be noticed long before noticing a decrease in the power end oil level due to the differences in volumes between the engine and the power end.

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Triplex Pump Training Module

Schlumberger Confidential

PAGE : 42 December 1999

Triplex Pump Training Module

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Another of the power end lube pumps is the Webster Brand pump; these gear type pumps are obsolete and must be replaced with Tyrone pump. When doing so a complete kit must be ordered for replacement, as the angle drive must be machined to except a mounting adapter and special mounting screws.

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Triplex Pump Training Module

PAGE : 44 December 1999

Some earlier model units used “Brown and Sharpe” gear type lube pumps. These pumps were typically driven by a hydraulic pump and mounted under the frame of trucks or on some “Offshore skids”. All of these pumps are positive displacement type pumps.

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Triplex Pump Training Module

PAGE : 45 December 1999

Fluid End Lubrication Systems Next we will discuss the two different Fluid End lubrication systems. The first of which uses an air-driven pump to transfer packing oil to the plungers. Check valves are installed directly to the fluid end in the event of complete packing failure, product such as cement will not migrate into the small oil lines. The divider block is used in these systems. 3.3

Fluid End For optimum packing life, it is essential that the plungers and the packing be properly lubricated. It takes only a few seconds for improperly lubricated packing to begin leaking. This in turn will ruin the plungers by damaging their polished surface, especially when pumping abrasive fluids such as cement slurry or drilling mud. Inadequate lubrication also causes heat generation, which also shortens the life of the packing. The type of oil used plays an important roll in packing life. A good oil to use is a Steam Cylinder oil, when if you look at it a triplex pump is just that a Cylinder. Steam cylinder oils have a large amount of tactafiers this allows it to stick to the plunger much longer than conventional motor oil. Steam Cylinder oils usually have a high viscosity above 400 to 1000, the best one to use depend on your climate. The Alemite pump used for the lubrication system is actually a grease pump so the high viscosity is not a problem for this pump. Another factor is the high viscosity decreases the oil consumption tremendously, which offsets any cost differentials. Note: Never reuse packing oil as dirt and debre will always contaminate the system and damage the pump and plug the divider blocks.

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Triplex Pump Training Module

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PAGE : 46 December 1999

Triplex Pump Training Module 3.3.1

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PAGE : 47 December 1999

Triplex Pump Training Module

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The Divider blocks uses a code with either the number 12 or 24, the number 12 indicates that the block will discharge out of one side. The number 24 indicates the block will discharge out of both sides. This cannot be changed. The block cannot be plugged in any port, because the block must complete it’s cycle plugging any hole will stop the cycle and shut down the whole lubrication system. If it becomes necessary to abort lubrication to a centrifugal pump for example. The hose can be rerouted to the reservoir to allow the block to continue its cycle.

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Triplex Pump Training Module

PAGE : 49 December 1999

Lubrication System No. 1- Alemite Pump Method of lubrication Lubricant Capacity

Force Feed(air-driven Alemite pump) Packing Lubrication oil 20 gals (average)

The air-operated pump (Alemite Pump) delivers lubricating oil to a divider block (McCord Divider Block) which in turn delivers oil equally to each plunger. The outlet from the divider block is connected through a check valve to each individual fluid end-packing bore. From there, it goes into the fluid end and enters the lantern gland for even distribution to the packing. The Alemite pump also provides lubrication to the C-Pumps via a parallel discharge line, or on older units via the divider block. The current Alemite pump used on the PG series (cementing) pumps is the Model 9668 medium pressure (5:1 ratio) pump. The pump section works in conjunction with the Pneumatic Logic Air Motor Model 338066A1.

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Triplex Pump Training Module

PAGE : 50 December 1999

To adjust the Alemite pump rate, first set the air pressure regulator to between 110-120 psi. Then control the desired amount of packing lube oil by regulating the metering valve on the discharge side of the pump. Unlike previous model Alemite pumps, adjusting the lubrication by the sound of the air motor will cause over lubrication and will not help to minimize environmental waste.

Note: On the Model 338066-A1 Pneumatic Logic Air Motors, an air lubricator system must not be used as on previous Alemite pumps. These motors are already packed with Teflon lubricant and require no additional lubricate except during service/repair. But does require clean dry air. Note: A blockage in any of the oil delivery lines will normally mean the failure of the entire plunger lubricating system, since the McCord Divider Block will not operate at all if any of its outlet ports are blocked. Accordingly, on all current-generation pump units, a lube oil filter is installed downstream of the Alemite pump. Refer to the section on Care & Maintenance in this manual for maintenance and trouble-shooting of the Alemite Pump, Lube Oil Filter, and the McCord Divider Block. Additional information can also be found in the Maintenance Manual (Section 1-Lubrication, Bulletin Numbers 804 and 982).

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