mud pump pulsation dampener precharge pressure in stock
A properly serviced pulsation dampener is critical for your mud pumps’ efficiency, safety, and performance. Unfortunately, there aren’t many resources available to educate personnel on executing safe and effective servicing procedures. Please review the following steps with your personnel for safe pulsation dampener maintenance.
Should you or your personnel have any questions regarding pulsation dampener maintenance, please don’t hesitate to ask. Sigma is more than happy to help you to ensure safe and proper care is being completed on your pulsation dampening equipment.
The Charge Free Dampening System™ is the first and only complete dampening system designed for maximum performance and cost savings. With the highest pressure rating at 10,000 psi, the CFD System far surpasses any pulsation control equipment in the drilling market today. Sigma’s system utilizes both appendage and flow-through technologies and yet still maintains the most compact design.
This multistage system utilizes several of Sigma’s advanced products that are proven to maximize efficiencies and upgrade operations of any reciprocating pumping system by themselves.
By protectively coating both inside and outside the system’s Charge Free Stabilizer™ and the Charge Free Dampener™, the system is entirely corrosion-resistant. The Charge Free Dampening System™ is easily the most protected pulsation equipment available.
The Charge Free Dampening System™ is categorically the most sophisticated pulsation control available for your rigs’ pumping operations. With the introduction of the CFD System, Sigma Drilling Technologies proves to be the authority on state-of-the-art advancements in pulsation control technologies.
The Pulsation Dampener 3375-0015-3 from the Hypro series assures smooth discharge from piston and plunger pumps. It also reduces peak loading on pump bearings and other internal parts. The Pulsation Dampener 3375-0015-3 extends the system life and minimizes maintenance costs.
As a general guideline, when using two cylinder or four cylinder piston pumps, the dampener charge should be approximantely 1/2 of the pump operating pressure. When using a three or six cylinder pump, te dampener charge should be approximately 2/3 of the pump operating pressure. This pump is rated for up to 1500 psi.
The pulsation dampeners shall be installed properly to reduce the pressure fluctuation and smooth the liquid flow. In order to extend the lifespan of the air bag, it is highly recommended to maintain the suggested proportion of the pump pressure to the pre-charge pressure of the air bag for the pulsation dampeners. Generally, the pump pressure shall be 2/3 that of the discharge pressure and no more than 4.5MPa.
2. During maintenance, the pump pressure and the pressure inside the pulsation dampeners shall be zero. Since the residual pressure is generally small and can not be indicated on the pressure gauge, user shall confirm the pressure carefully to avoid accident caused by low pressure.
Mud pump pulsation dampeneris the mud pump discharge end main component, installs in the hydraulic end discharge pipe one end, plays the stable pressure and the pressure compensation function, the air bag work pressure is the mud pump work pressure 80%.Attention should be paid to the use of air bag, must be the first pressure relief.The mud pump of F500/F800 USES kb-45 air bag, and the mud pump of F1000/F1300/F1600 USES kb-75 air bag.The middle tie rod produced by our company is made of 35CrMo material, which has a smooth surface after chrome plating and fine grinding, greatly improving the wear resistance and corrosion resistance.
Proper installation and use of pulsation dampener can effectively reduce pressure fluctuations in the discharge system, thus achieving a more uniform fluid flow.In order to achieve a high service life of the air bag, always maintain the recommended ratio between the pump pressure and the air bag precharge pressure (generally not more than 2/3 of the pump discharge pressure, the maximum should not exceed 4.5mpa).
2. In the maintenance of air bag, air bag pressure must be zero, the pump pressure must be zero.Cannot rely on the pressure gauge to judge, because the residual pressure is small, the pressure gauge can not be displayed, but this low pressure will also lead to accidents!
Product&Reapir: Crown block(TC225 TC250 TC315 TC450 TC585), Travelling block(YC225 YC250 YC315 YC350 YC450 YC450S YC585), Hook(DG225 DG250 DG315 DG350 DG450 DG585 DG675), Rotary table(ZP175 ZP205 ZP275 ZP375 ZP975AS ZP495), Swivel(SL225 SL250 SL450 SL585), Drawworks(JC20 JC30 JC40 JC50 JC70B JC90DB), Mud pump (F-500 F-800 F-1000 F-1300 F-1600 F-1600HL F-2200 F-2200HL 3NB500C,3NB1000C 3NB1300C 3NB1600 SL3NB-1000 SL3NB-1300A SL3NB-1600A),BOP(FH,FZ,Cameron,Shaffer), Control System for Surface Mounted BOP Stacks(FKQ,FKDQ),Disc brake (PS,PSZ, DBS), Bladder accumulator (NXQ), Drilling rig(ZJ40/2250DZ ZJ50/3150DZ ZJ70/4500DZ ZJ90/6750DZ), Workover rig (XJ40,XJ60, XJ80,XJ100,XJ12,ZJ15,ZJ20,ZJ3,XJ350, XJ450, XJ550,XJ650,XJ750), BPM Top drive((DQ120BSC, DQ90BSD, DQ90BSC, DQ80BSC, DQ70BSD, DQ70BSE, DQ70BSC, DQ50BC, DQ40BC, DQ40BSG, DQ40BCQ, DQ40YR, DQ30Y) Make: Bomco, Lanzhou LS,LSPE, SJ Petro, RG Petro, Sichuan Honghua, CPTDC, Beijing BPM, Shanghai Shenkai, Kingdream, CCDC, SJS Serva, DFXK, LS-NOV, Beijing PSK, Gold basin, Renqiu Boke,Guangdong Dongsu.(Guangshi), XBSY.,Tiehu, Rongsheng (HBRS), TSC. Replacements:Mission magnum/Halco centrifugal pump, Cameron FC gate valve,Cameron R check valve, Demco mud valveE( 3K&5K ), Demco butterfly valve,BJ varco handling tools (SDXL, SDML, SDS,DCS,SSC,SSD,YT, HYC, LYT, MP,MYT, MG, RGG, HGG, MGG, TA, SJ), MI SWACO / Mongoose / Derrick / /Brandt / King cobra shale shaker screen (FLC2000,FLC503,Derrick 626), M/D & OTECO Gauge(Type F,Type D,Model 6,Model 7,Model 8), Twin disc,WPT, Eaton clutch & friction disc, National (10-P-130,12-P-160 ,14-P-220 ,8-P-80 ,9-P-100), Gardner denver (PZ-7,PZ-8,PZ-9,PZ-10,PZ-11), EMSCO FB1600.International Brand: Moog, CCS, ATOS, Rexroth, Eaton, Flowrox, Italvibras, Martin, Norgren, Parker, Siemens, Vickers, 3M.Standard:API Spec 4F, API Spec 6A,API Spec 6D,API Spec 600, API Spec 7K, API Spec 8A, API Spec 8C,API Spec 16A, API Spec 16C, API Spec 16D
6500 Brittmoore Houston, Texas 77041-5109 281-931-8550 888-MUD-PUMP www.lewco-equip.com FAX 713-856-5341February 24, 2003 Page 1 of 9 Table of Contents
The Model L20-7500-DNV Discharge Pulsation Dampener....................................3Assembly Drawing ........................................................................................................4Parts List ........................................................................................................................5Mounting Instructions ..................................................................................................6Precharge Pressure Levels ...........................................................................................7Overhaul Kit ..................................................................................................................8Recommended Spare Parts ..........................................................................................9
6500 Brittmoore Houston, Texas 77041-5109 281-931-8550 888-MUD-PUMP www.lewco-equip.com FAX 713-856-5341February 24, 2003 Page 2 of 9 The Model L20-7500-DNV Discharge Pulsation DampenerThe LEWCO pulsation dampener is designed to counter the effect of pulsations often associatedwith positive displacement reciprocating pumps. The L20-7500-DNV has a dampening volumeof 20 gallons and is rated for a maximum allowable working pressure of 7,500 psi. The L20’sdesign focuses on durability and simplicity. Since the L20 uses a minimum number of parts, it iscompletely field serviceable, thereby eliminating costly shop repairs and down time. Areplaceable bottom plate having a 4 1/16” API 10,000 connection comes as a standard feature,which is ideal when working with abrasive or corrosive fluids. The large top flange allows forreplacement of the diaphragm bladder without removing the unit from the line. The stainlesssteel charge valve and pressure gage are located on the top flange and protected by a heavy-dutycover that also serves as a lifting eye. Each complete unit is hydrostatically tested to 11,250 psibefore shipment. Ask for LEWCO part number C305026
6500 Brittmoore Houston, Texas 77041-5109 281-931-8550 888-MUD-PUMP www.lewco-equip.com FAX 713-856-5341February 24, 2003 Page 3 of 9 Assembly Drawing Model L20-7500-DNV Discharge Pulsation Dampener P/N C305026
6500 Brittmoore Houston, Texas 77041-5109 281-931-8550 888-MUD-PUMP www.lewco-equip.com FAX 713-856-5341February 24, 2003 Page 4 of 9
Read All Instructions Before Attempting to Install This Dampener.Use Safe Lifting Practices Whenever The Dampener Is Installed Or Moved. The Dampener Lifting Cap Is Designed To Lift The Dampener Only. The Dampener Must Be Completely Unflanged Before It Is Lifted.
The LEWCO Model L20-7500-DNV dampener should be mounted preferably in the verticalposition. When other conditions exist, an angular or inverted installation is acceptable and doesnot impede dampener performance. However, increased corrosion could occur due to trappedfluid.
LEWCO dampeners use ANSI and API flanged connections and NPT type threaded connections.For flanged connections, position the dampener on a gasket and mating flange so that it iscentered. Install nuts hand tight. Cross-tighten nuts one turn at a time to proper torque to insureuniform load. The torque value for the 1-1/8” stud is 778 ft. lbs.
6500 Brittmoore Houston, Texas 77041-5109 281-931-8550 888-MUD-PUMP www.lewco-equip.com FAX 713-856-5341February 24, 2003 Page 6 of 9 Precharge Pressure Levels Model L20-7500-DNV Discharge Pulsation Dampeners
x For maximum operating efficiency, the precharge pressure should be 75 percent of the minimum operating system pressure or 2,000 psig* , whichever is lower.
x For normal operating conditions, the precharge pressure should be 50 percent to 60 percent of the average operating system pressure or 2,000 psig*, whichever is lower.
x For limited operating conditions, the precharge pressure should be maintained between 30 percent to 75 percent of the average system operating pressure or 2,000 psig*, whichever is lower.
PRECHARGING General Precharging Directions Model L20-7500-DNV Discharge Pulsation DampenerThe charging valve and the pressure gauge are located under the dampener lifting cap, and theyare exposed by removing the lifting cap. Before precharging the dampener, make sure all coverstud nuts are tightened evenly and no pressure is on the operating system.
Connect one end of the hose assembly to a standard commercially available nitrogen bottle andthe other end to the charging valve located at the top of the dampener. Precharge from a standard224 cubic foot 2,200 psig nitrogen bottle equipped with a pressure regulator. Open the bottleregulator valve until recommended precharge pressure shows on the regulator gauge. Slowlyopen the charging valve on the dampener by turning the top hex nut 3 to 4 complete turnscounter-clockwise.
Allow pressure to increase in the dampener until dampener pressure gauge reads specifiedprecharge pressure. This process normally takes 5 to 15 minutes. Dampener gauge and regulatorgauge should read the same and be equal to the specified precharge pressure. Close theprecharge valve, then close the regulator valve at the nitrogen bottle. The sound of escaping gasmay be heard at the charging valve until the regulator is closed.
6500 Brittmoore Houston, Texas 77041-5109 281-931-8550 888-MUD-PUMP www.lewco-equip.com FAX 713-856-5341February 24, 2003 Page 7 of 9 Overhaul Kit Model L20-7500-DNV Discharge Pulsation Dampener
ITEM QTY PART NO. DESCRIPTION 2 1 EG145 Pressure Gauge 3 1 EV215 Charging Valve 7 1 002-1666 Stabilizer Plate Bolt 8 1 002-1544 Lock Washer 9 1 108-0620 Stabilizer Plate 10 1 108-0619 Stabilizer 11 1 108-0618 Diaphragm Bladder 13 8 EN137 Nut Hvy. Hex. 1-1/8”-7 15 1 108-0656 Bottom Flange Seal 17 8 ES174 Bottom Flange Stud 19 1 EO190 Charging Valve O-Ring 25 1 108-0065 Ring Gasket
6500 Brittmoore Houston, Texas 77041-5109 281-931-8550 888-MUD-PUMP www.lewco-equip.com FAX 713-856-5341February 24, 2003 Page 8 of 9 Recommended Spare Parts Model L20-7500-DNV Discharge Pulsation Dampener
Item Qty Part No. Description 2 2 EG145 Pressure Gauge 3 2 EV215 Charging Valve 4 12 ES175 Top Flange Bolt 5 12 EN132 Top Flange Nut 7 1 002-1666 Stabilizer Plate Bolt 8 1 002-1544 Lock Washer 9 1 108-0620 Stabilizer Plate 10 1 108-0619 Stabilizer 11 1 108-0618 Diaphragm Bladder 13 8 EN137 Nut Hvy Hex. 1-1/8”-7 14 8 EC181 Bottom Flange Cap Screw 15 2 108-0656 Bottom Flange Seal 16 4 002-1629 Lifting Cap Bolt 19 2 EO190 Charging Valve O-Ring 25 1 108-0065 Ring Gasket 26 1 B310066 Charging Hose Assembly
6500 Brittmoore Houston, Texas 77041-5109 281-931-8550 888-MUD-PUMP www.lewco-equip.com FAX 713-856-5341February 24, 2003 Page 9 of 9
Product&Reapir: Crown block(TC225 TC250 TC315 TC450 TC585), Travelling block(YC225 YC250 YC315 YC350 YC450 YC450S YC585), Hook(DG225 DG250 DG315 DG350 DG450 DG585 DG675), Rotary table(ZP175 ZP205 ZP275 ZP375 ZP975AS ZP495), Swivel(SL225 SL250 SL450 SL585), Drawworks(JC20 JC30 JC40 JC50 JC70B JC90DB), Mud pump (F-500 F-800 F-1000 F-1300 F-1600 F-1600HL F-2200 F-2200HL 3NB500C,3NB1000C 3NB1300C 3NB1600 SL3NB-1000 SL3NB-1300A SL3NB-1600A),BOP(FH,FZ,Cameron,Shaffer), Control System for Surface Mounted BOP Stacks(FKQ,FKDQ),Disc brake (PS,PSZ, DBS), Bladder accumulator (NXQ), Drilling rig(ZJ40/2250DZ ZJ50/3150DZ ZJ70/4500DZ ZJ90/6750DZ), Workover rig (XJ40,XJ60, XJ80,XJ100,XJ12,ZJ15,ZJ20,ZJ3,XJ350, XJ450, XJ550,XJ650,XJ750), BPM Top drive((DQ120BSC, DQ90BSD, DQ90BSC, DQ80BSC, DQ70BSD, DQ70BSE, DQ70BSC, DQ50BC, DQ40BC, DQ40BSG, DQ40BCQ, DQ40YR, DQ30Y) Make: Bomco, Lanzhou LS,LSPE, SJ Petro, RG Petro, Sichuan Honghua, CPTDC, Beijing BPM, Shanghai Shenkai, Kingdream, CCDC, SJS Serva, DFXK, LS-NOV, Beijing PSK, Gold basin, Renqiu Boke,Guangdong Dongsu.(Guangshi), XBSY.,Tiehu, Rongsheng (HBRS), TSC. Replacements:Mission magnum/Halco centrifugal pump, Cameron FC gate valve,Cameron R check valve, Demco mud valveE( 3K&5K ), Demco butterfly valve,BJ varco handling tools (SDXL, SDML, SDS,DCS,SSC,SSD,YT, HYC, LYT, MP,MYT, MG, RGG, HGG, MGG, TA, SJ), MI SWACO / Mongoose / Derrick / /Brandt / King cobra shale shaker screen (FLC2000,FLC503,Derrick 626), M/D & OTECO Gauge(Type F,Type D,Model 6,Model 7,Model 8), Twin disc,WPT, Eaton clutch & friction disc, National (10-P-130,12-P-160 ,14-P-220 ,8-P-80 ,9-P-100), Gardner denver (PZ-7,PZ-8,PZ-9,PZ-10,PZ-11), EMSCO FB1600.International Brand: Moog, CCS, ATOS, Rexroth, Eaton, Flowrox, Italvibras, Martin, Norgren, Parker, Siemens, Vickers, 3M.Standard:API Spec 4F, API Spec 6A,API Spec 6D,API Spec 600, API Spec 7K, API Spec 8A, API Spec 8C,API Spec 16A, API Spec 16C, API Spec 16D
6500 Brittmoore Houston, Texas 77041-5109 281-931-8550 888-MUD-PUMP www.lewco-equip.com FAX 713-856-5341February 24, 2003 Page 1 of 9 Table of Contents
The Model L20-7500-DNV Discharge Pulsation Dampener....................................3Assembly Drawing ........................................................................................................4Parts List ........................................................................................................................5Mounting Instructions ..................................................................................................6Precharge Pressure Levels ...........................................................................................7Overhaul Kit ..................................................................................................................8Recommended Spare Parts ..........................................................................................9
6500 Brittmoore Houston, Texas 77041-5109 281-931-8550 888-MUD-PUMP www.lewco-equip.com FAX 713-856-5341February 24, 2003 Page 2 of 9 The Model L20-7500-DNV Discharge Pulsation DampenerThe LEWCO pulsation dampener is designed to counter the effect of pulsations often associatedwith positive displacement reciprocating pumps. The L20-7500-DNV has a dampening volumeof 20 gallons and is rated for a maximum allowable working pressure of 7,500 psi. The L20’sdesign focuses on durability and simplicity. Since the L20 uses a minimum number of parts, it iscompletely field serviceable, thereby eliminating costly shop repairs and down time. Areplaceable bottom plate having a 4 1/16” API 10,000 connection comes as a standard feature,which is ideal when working with abrasive or corrosive fluids. The large top flange allows forreplacement of the diaphragm bladder without removing the unit from the line. The stainlesssteel charge valve and pressure gage are located on the top flange and protected by a heavy-dutycover that also serves as a lifting eye. Each complete unit is hydrostatically tested to 11,250 psibefore shipment. Ask for LEWCO part number C305026
6500 Brittmoore Houston, Texas 77041-5109 281-931-8550 888-MUD-PUMP www.lewco-equip.com FAX 713-856-5341February 24, 2003 Page 3 of 9 Assembly Drawing Model L20-7500-DNV Discharge Pulsation Dampener P/N C305026
6500 Brittmoore Houston, Texas 77041-5109 281-931-8550 888-MUD-PUMP www.lewco-equip.com FAX 713-856-5341February 24, 2003 Page 4 of 9
Read All Instructions Before Attempting to Install This Dampener.Use Safe Lifting Practices Whenever The Dampener Is Installed Or Moved. The Dampener Lifting Cap Is Designed To Lift The Dampener Only. The Dampener Must Be Completely Unflanged Before It Is Lifted.
The LEWCO Model L20-7500-DNV dampener should be mounted preferably in the verticalposition. When other conditions exist, an angular or inverted installation is acceptable and doesnot impede dampener performance. However, increased corrosion could occur due to trappedfluid.
LEWCO dampeners use ANSI and API flanged connections and NPT type threaded connections.For flanged connections, position the dampener on a gasket and mating flange so that it iscentered. Install nuts hand tight. Cross-tighten nuts one turn at a time to proper torque to insureuniform load. The torque value for the 1-1/8” stud is 778 ft. lbs.
6500 Brittmoore Houston, Texas 77041-5109 281-931-8550 888-MUD-PUMP www.lewco-equip.com FAX 713-856-5341February 24, 2003 Page 6 of 9 Precharge Pressure Levels Model L20-7500-DNV Discharge Pulsation Dampeners
x For maximum operating efficiency, the precharge pressure should be 75 percent of the minimum operating system pressure or 2,000 psig* , whichever is lower.
x For normal operating conditions, the precharge pressure should be 50 percent to 60 percent of the average operating system pressure or 2,000 psig*, whichever is lower.
x For limited operating conditions, the precharge pressure should be maintained between 30 percent to 75 percent of the average system operating pressure or 2,000 psig*, whichever is lower.
PRECHARGING General Precharging Directions Model L20-7500-DNV Discharge Pulsation DampenerThe charging valve and the pressure gauge are located under the dampener lifting cap, and theyare exposed by removing the lifting cap. Before precharging the dampener, make sure all coverstud nuts are tightened evenly and no pressure is on the operating system.
Connect one end of the hose assembly to a standard commercially available nitrogen bottle andthe other end to the charging valve located at the top of the dampener. Precharge from a standard224 cubic foot 2,200 psig nitrogen bottle equipped with a pressure regulator. Open the bottleregulator valve until recommended precharge pressure shows on the regulator gauge. Slowlyopen the charging valve on the dampener by turning the top hex nut 3 to 4 complete turnscounter-clockwise.
Allow pressure to increase in the dampener until dampener pressure gauge reads specifiedprecharge pressure. This process normally takes 5 to 15 minutes. Dampener gauge and regulatorgauge should read the same and be equal to the specified precharge pressure. Close theprecharge valve, then close the regulator valve at the nitrogen bottle. The sound of escaping gasmay be heard at the charging valve until the regulator is closed.
6500 Brittmoore Houston, Texas 77041-5109 281-931-8550 888-MUD-PUMP www.lewco-equip.com FAX 713-856-5341February 24, 2003 Page 7 of 9 Overhaul Kit Model L20-7500-DNV Discharge Pulsation Dampener
ITEM QTY PART NO. DESCRIPTION 2 1 EG145 Pressure Gauge 3 1 EV215 Charging Valve 7 1 002-1666 Stabilizer Plate Bolt 8 1 002-1544 Lock Washer 9 1 108-0620 Stabilizer Plate 10 1 108-0619 Stabilizer 11 1 108-0618 Diaphragm Bladder 13 8 EN137 Nut Hvy. Hex. 1-1/8”-7 15 1 108-0656 Bottom Flange Seal 17 8 ES174 Bottom Flange Stud 19 1 EO190 Charging Valve O-Ring 25 1 108-0065 Ring Gasket
6500 Brittmoore Houston, Texas 77041-5109 281-931-8550 888-MUD-PUMP www.lewco-equip.com FAX 713-856-5341February 24, 2003 Page 8 of 9 Recommended Spare Parts Model L20-7500-DNV Discharge Pulsation Dampener
Item Qty Part No. Description 2 2 EG145 Pressure Gauge 3 2 EV215 Charging Valve 4 12 ES175 Top Flange Bolt 5 12 EN132 Top Flange Nut 7 1 002-1666 Stabilizer Plate Bolt 8 1 002-1544 Lock Washer 9 1 108-0620 Stabilizer Plate 10 1 108-0619 Stabilizer 11 1 108-0618 Diaphragm Bladder 13 8 EN137 Nut Hvy Hex. 1-1/8”-7 14 8 EC181 Bottom Flange Cap Screw 15 2 108-0656 Bottom Flange Seal 16 4 002-1629 Lifting Cap Bolt 19 2 EO190 Charging Valve O-Ring 25 1 108-0065 Ring Gasket 26 1 B310066 Charging Hose Assembly
6500 Brittmoore Houston, Texas 77041-5109 281-931-8550 888-MUD-PUMP www.lewco-equip.com FAX 713-856-5341February 24, 2003 Page 9 of 9
Mud pump pulsation dampeneris the mud pump discharge end main component, installs in the hydraulic end discharge pipe one end, plays the stable pressure and the pressure compensation function, the air bag work pressure is the mud pump work pressure 80%.Attention should be paid to the use of air bag, must be the first pressure relief.The mud pump of F500/F800 USES kb-45 air bag, and the mud pump of F1000/F1300/F1600 USES kb-75 air bag.The middle tie rod produced by our company is made of 35CrMo material, which has a smooth surface after chrome plating and fine grinding, greatly improving the wear resistance and corrosion resistance.
Proper installation and use of pulsation dampener can effectively reduce pressure fluctuations in the discharge system, thus achieving a more uniform fluid flow.In order to achieve a high service life of the air bag, always maintain the recommended ratio between the pump pressure and the air bag precharge pressure (generally not more than 2/3 of the pump discharge pressure, the maximum should not exceed 4.5mpa).
2. In the maintenance of air bag, air bag pressure must be zero, the pump pressure must be zero.Cannot rely on the pressure gauge to judge, because the residual pressure is small, the pressure gauge can not be displayed, but this low pressure will also lead to accidents!
Mud pump is one of the most critical equipment on the rig; therefore personnel on the rig must have good understanding about it. We’ve tried to find the good training about it but it is very difficult to find until we’ve seen this VDO training and it is a fantastic VDO training about the basic of mud pumps used in the oilfield. Total length of this VDO is about thirteen minutes and it is worth to watch it. You will learn about it so quickly. Additionally, we also add the full detailed transcripts which will acceleate the learning curve of learners.
Powerful mud pumps pick up mud from the suction tank and circulate the mud down hole, out the bit and back to the surface. Although rigs usually have two mud pumps and sometimes three or four, normally they use only one at a time. The others are mainly used as backup just in case one fails. Sometimes however the rig crew may compound the pumps, that is, they may use three or four pumps at the same time to move large volumes of mud when required.
Rigs use one of two types of mud pumps, Triplex pumps or Duplex pumps. Triplex pumps have three pistons that move back-and-forth in liners. Duplex pumps have two pistons move back and forth in liners.
Triplex pumps have many advantages they weight 30% less than a duplex of equal horsepower or kilowatts. The lighter weight parts are easier to handle and therefore easier to maintain. The other advantages include;
• One of the more important advantages of triplex over duplex pumps, is that they can move large volumes of mud at the higher pressure is required for modern deep hole drilling.
Triplex pumps are gradually phasing out duplex units. In a triplex pump, the pistons discharge mud only when they move forward in the liner. Then, when they moved back they draw in mud on the same side of the piston. Because of this, they are also called “single acting.” Single acting triplex pumps, pump mud at a relatively high speeds. Input horsepower ranges from 220 to 2200 or 164 to 1641 kW. Large pumps can pump over 1100 gallons per minute, over 4000 L per minute. Some big pumps have a maximum rated pressure of over 7000 psi over 50,000 kPa with 5 inch/127 mm liners.
Here is a schematic of a triplex pump. It has three pistons each moving in its own liner. It also has three intake valves and three discharge valves. It also has a pulsation dampener in the discharge line.
Look at the piston at left, it has just completed pushing mud out of the liner through the open discharge valve. The piston is at its maximum point of forward travel. The other two pistons are at other positions in their travel and are also pumping mud. But for now, concentrate on the left one to understand how the pump works. The left piston has completed its backstroke drawing in mud through the open intake valve. As the piston moved back it instead of the intake valve off its seat and drew mud in. A strong spring holds the discharge above closed. The left piston has moved forward pushing mud through the now open discharge valve. A strong spring holds the intake valve closed. They left piston has completed its forward stroke they form the length of the liner completely discharging the mud from it. All three pistons work together to keep a continuous flow of mud coming into and out of the pump.
Crewmembers can change the liners and pistons. Not only can they replace worn out ones, they can also install different sizes. Generally they use large liners and pistons when the pump needs to move large volumes of mud at relatively low pressure. They use a small liners and pistons when the pump needs to move smaller volumes of mud at a relatively high pressure.
In a duplex pump, pistons discharge mud on one side of the piston and at the same time, take in mud on the other side. Notice the top piston and the liner. As the piston moves forward, it discharges mud on one side as it draws in mud on the other then as it moves back, it discharges mud on the other side and draws in mud on the side it at had earlier discharge it. Duplex pumps are therefore double acting.
Double acting pumps move more mud on a single stroke than a triplex. However, because of they are double acting they have a seal around the piston rod. This seal keeps them from moving as fast as a triplex. Input horsepower ranges from 190 to 1790 hp or from 142 to 1335 kW. The largest pumps maximum rated working pressure is about 5000 psi, almost 35,000 kPa with 6 inch/152 mm linings.
A mud pump has a fluid end, our end and intake and the discharge valves. The fluid end of the pump contains the pistons with liners which take in or discharge the fluid or mud. The pump pistons draw in mud through the intake valves and push mud out through the discharge valves.
The power end houses the large crankshaft and gear assembly that moves the piston assemblies on the fluid end. Pumps are powered by a pump motor. Large modern diesel/electric rigs use powerful electric motors to drive the pump. Mechanical rigs use chain drives or power bands (belts) from the rig’s engines and compounds to drive the pump.
A pulsation dampener connected to the pump’s discharge line smooths out surges created by the pistons as they discharge mud. This is a standard bladder type dampener. The bladder and the dampener body, separates pressurized nitrogen gas above from mud below. The bladder is made from synthetic rubber and is flexible. When mud discharge pressure presses against the bottom of the bladder, nitrogen pressure above the bladder resists it. This resistance smoothes out the surges of mud leaving the pump.
Here is the latest type of pulsation dampener, it does not have a bladder. It is a sphere about 4 feet or 1.2 m in diameter. It is built into the mud pump’s discharge line. The large chamber is form of mud. It has no moving parts so it does not need maintenance. The mud in the large volume sphere, absorbs this surges of mud leaving the pump.
A suction dampener smooths out the flow of mud entering into the pump. Crewmembers mount it on the triplex mud pump’s suction line. Inside the steel chamber is a air charged rubber bladder or diaphragm. The crew charges of the bladder about 10 to 15 psi/50 to 100 kPa. The suction dampener absorbs surges in the mud pump’s suction line caused by the fast-moving pump pistons. The pistons, constantly starts and stops the mud’s flow through the pump. At the other end of the charging line a suction pumps sends a smooth flow of mud to the pump’s intake. When the smooth flow meets the surging flow, the impact is absorbed by the dampener.
Workers always install a discharge pressure relief valve. They install it on the pump’s discharge side in or near the discharge line. If for some reason too much pressure builds up in the discharge line, perhaps the drill bit or annulus gets plugged, the relief valve opens. That opened above protects the mud pump and system damage from over pressure.
Some rig owners install a suction line relief valve. They install it on top of the suction line near the suction dampener. They mount it on top so that it won’t clog up with mud when the system is shut down. A suction relief valve protects the charging pump and the suction line dampener. A suction relief valve usually has a 2 inch or 50 mm seat opening. The installer normally adjusts it to 70 psi or 500 kPa relieving pressure. If both the suction and the discharged valves failed on the same side of the pump, high back flow or a pressure surge would occur. The high backflow could damage the charging pump or the suction line dampener. The discharge line is a high-pressure line through which the pump moves mud. From the discharge line, the mud goes through the stand pipe and rotary hose to the drill string equipment.
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