Plunger pump maintenance and overhaul procedures

Piston Pump Maintenance and Overhaul Regulations

I. Equipment Structure Diagram and Performance Principle 1.Equipment Structure Diagram

1.1 Structure Brief Description: The piston pump is mainly composed of hydraulic cylinder, piston, crosshead, guide, crankshaft, slider, pump frame and other components

. Driven by the motor through the coupling, reducer and adjustment mechanism.

2. Principle of equipment performance

2.1 The crankshaft of the pump is driven by the motor through the speed reducer and coupling, and the crankshaft drives the connecting rod, the crosshead, the intermediate rod, and the plunger to do the reciprocating motion. When the plunger moves backward, the inlet valve opens, and the liquid enters into the pump body, and the process of inletting liquid is finished until the plunger moves to the last position (the crankshaft rotates 180°). When the plunger starts to move forward, the liquid in the pump case is squeezed, the pressure rises, the inlet valve closes, the inlet valve opens and the liquid is removed.

II. Overhaul

1. Scope of application and the basis of preparation, standards and references

1.1 This procedure is applicable to the maintenance and overhaul of reciprocating piston pumps commonly used in chemical plants, and the maintenance and overhaul of special-purpose horizontal piston pumps as well as vertical piston pumps can be referred to the implementation of the maintenance and overhaul. 1.2 Prepared standards and references catalog

HGJ 1027-79 chemical plant plunger pump maintenance and overhaul procedures

"Chemical Plant Machinery Manual" Chemical Industry Press 1989 SHS 01001-2004 Petrochemical equipment intact equipment 2. overhaul cycle, overhaul category and overhaul content

When the unit condition monitoring means, already have the conditions to carry out predictive maintenance, after requesting the approval of the unit's higher-level authorities, may not be subject to the limitations of this article. 2.2 Inspection and maintenance content 2.2.1 Minor maintenance

2.2.1.1 Replace the seal packing and eliminate the leakage point.

2.2.1.2 Check, clean the filters of the pump inlet and oil system, and replace the lubricant. 2.2.1.3 Check and tighten each bolt.

2.2.1.4 Check and repair the inlet and outlet valve group parts.

2.2.1.5 Check and repair the coupling parts.

2.2.1.6 Check, adjust or replace the fragile parts and components. 2.2.2 Intermediate Repair

2.2.2.1 Including minor repair items.

2.2.2.2 Repair or replacement of inlet and outlet manifold parts.

2.2.2.3 Repair or scrape each shaft tile and inspect or replace bearings.

2.2.2.4 Check or repair the plunger, crosshead, slide, crankshaft and other major parts. 2.2.2.5 Calibrate the pressure gauge, safety valve, metering and adjusting mechanism. 2.2.2.6 Check and clean reducer. 2.2.3 Overhaul

2.2.3.1 Including medium repair items.

2.2.3.2 Disassembly, cleaning, inspection and measurement of parts and components.

2.2.3.3 Repair or replacement of major parts such as crankshaft, connecting rod, crosshead, plunger, etc. 2.2.3.4 Replace the axle shingles.

2.2.3.5 Level the body and re-align the crankshaft block. 2.2.3.6 Overhaul the reducer.

2.2.5.7 Repair the foundation and paint the body. 2.2.5.8 Motor inspection, repair and refueling. 3 overhaul preparation, inspection procedures and quality standards 3.1 pre-inspection preparation

3.1.1 to grasp the operating conditions, ready for the necessary drawings and related inspection records 3.1.2 ready for overhaul tools, gauges, fittings and materials.

3.1.3 Cut off the power supply and equipment and system contact, internal media cooling, purging, replacement of clean, in line with the safety of maintenance conditions. 3.2 Inspection procedure

3.2.1 Disassemble the coupling and check the pump alignment. 3.2.2 Disassemble accessories and ancillary piping

3.2.3 Disassemble the crosshead assembly and check the fit and wear of the crosshead, crosshead pin, crosshead and slide plate. 3.2.4 Disassemble the crankcase and check the crankshaft, connecting rods and bearings. 3.2.5 Disassemble the inlet and outlet valves on the pump body and check the parts and seals. 3.2.6 Disassemble the working cylinders and pistons, and check the wear and defects of the cylinders and pistons. 3.2.7 Disassemble the pump body and check the wear of the cylinders and the pistons. 3.2.7 Disassemble the reducer cover and check the bearing wear and gear meshing marks. 3.2.8 Disassemble the gear oil pump and check the gear meshing. 3.2.9 Check the ground bolts. 3.3 Inspection Quality Standards

3.3.1 Pump Frame

3.3.1.1 The pump frame should be free from defects such as sand holes and cracks. It should be filled with kerosene for 2-4 hours without leakage. Defects can be repaired by filler welding, welding should be slow preheating to 600-700 ° C before welding, welded immediately after heating to 650-700 ° C, insulation, slow cooling.

3.3.1.2 In the pump frame machining surface with a level meter to measure the level of the pump frame installation, longitudinal and transverse leveling error are not more than 0.05mm / m.

3.3.1.3 The combination of the frame and the top cover should be flat and smooth surface, tight assembly. For those without gaskets, check with the coloring method, 2-3 color marks per square centimeter on the surface, and evenly distributed. 3.3.2 Cylinder block

3.3.2.1 The inner surface of the cylinder should be smooth and free of scars, grooves, cracks and other defects. There are slight hair pulling and abrasion, can be used semicircular oil stone along the cylinder in the circumferential direction of grinding, scarring should be serious pinch cylinder. The maximum wear of the cylinder bore shall not exceed 2% of the original size.

3.3.2.2 The roundness and cylindricity error of the inner diameter of the cylinder body should not be more than half of the tolerance of the inner diameter, and should be processed when exceeding the standard.

3.3.2.3 Cylinder centerline straightness of 0.08mm/m.

3.3.2.4 Cylinder overhaul should be done when the hydrostatic test, the test pressure for the design pressure of 1,25 times the test pressure 10-15 minutes without leakage. Cylinder block due to corrosion, erosion thinning can not withstand hydrostatic test, should be scrapped. 3.3.3 Crankshaft

3.3.3.1 Crankshaft surfaces should be smooth and damage-free, the main shaft neck and crank neck abrasion dent area greater than 2% of the area of the journal, the depth of grooves on the journal of 0.30mm or more, can be used to grind or spray plating method of repair.

3.3.3.2 On the machine tool with a micrometer to detect the crank journal radial runout and cylindricity are half of the diameter tolerance; radial runout of the main journal for 0.03mm. more than the specified limit should be replaced.

3.3.3.3 The perpendicularity between the crankshaft centerline and the cylinder centerline is 0.15mm/m, which can be measured by the instrument and the cylinder pulling wire.

3.3.3.4 Crankshaft installation level error is less than 0.10mnl/m. 3.3.3.5 Crankshaft straightness is 0.05mm/m.

3.3.3.6 The main shaft journal and crankshaft journal diameter decreases by 1 percent, it should be renewed. 3.3.4 Connecting rod

3.3.4.1 Connecting rod should be done non-destructive flaw detection, there shall be no cracks and other defects.

3.3.4.2 The parallelism of the centerline of two holes of connecting skewers is 0.30mm/m, and it should be replaced if it exceeds the specified value. 3.3.5 Phillips head, slide and guide

3.3.5.1 Phillips head pin roundness and cylindricity of half of the appropriate diameter tolerance.

3.3.5.2 The surface of the crosshead, slide plate and guideway should be smooth and free of defects such as burrs and scars. If the contact surface of slide plate and guide rail has slight abrasion and gouge depth not more than 0.10mm, it can be repaired and polished by half-round oil stone.

3.3.5.3 The clearance between the crosshead pin and bushing is 0.03-0.06mm; the maximum limit clearance is not more than 0.12mm.

3.3.5.4 The clearance between the crosshead sliding plate and the guide rail is allowed to be two-thousandths of the diameter of the crosshead; the wear clearance is not more than 0.35mm.

3.3.5.5 The contact between the sliding plate and the guide rail shall be Uniform. 3.3.6 Plunger

3.3.6.1 Plunger surface should be free of cracks, dents, spots, burrs and other defects. There is a slight abrasion, groove depth of not more than 0.10mm, should be repaired and polished.

3.3.6.2 The wear of the plunger shall not exceed the provisions of Table 4.

3.3.7 Inlet and outlet valve group

3.3.7.1 Inlet and outlet valve group seat and spool cover is not allowed to have abrasions, scratches, corrosion, pitting and other defects. 3.3.7.2 Valve seat and spool should be paired wet grinding, grinding should maintain the original sealing surface curve width. 3.3.7.3 Seat and spool grinding with kerosene test, five minutes without leakage.

3.3.7.4 Check the spring, if there is broken or reduced elasticity, should be replaced. 3.3.7.5 The contact surface of the valve seat and the valve body should be closely fit.

3.3.7.9 The valve body mounted on the cylinder must be firm, tight, no loose leakage. 3.3.8 Slide bearing

3.3.8.1 When the slide bearing is serviced, the surface roughness inside the bearing should be checked to see if it meets the requirements. Whether the wear of the groove mark is serious; groove mark depth of more than 0.30mm, can be used to scrape scraper repair, research and re-adjustment of gaskets and clearance. 3.3.8.2 Check whether the oil channel, oil holes are smooth, and whether the lubrication is good.

3.3.8.3 The bearing alloy should not have cracks, pores and shells and other defects, and can be used to determine whether the combination of the bearing alloy and the bearing body is good by using kerosene immersion method and knocking and listening to the sound of the identification method.

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3.3.8.4 The journal and the bearing should be in uniform contact within 60-90o range directly below the journal, and the connecting rod tile should be in uniform contact within 60-75 range above the direction of force, and no less than 2-3 color prints per square centimeter should be examined by the color application method.

3.3.8.5 Bearing body and bearing seat, connecting rod tile and tile seat should be uniformly fit, with the coloring method to check the contact area of not less than 70% of the total area.

3.3.8.6 Main shaft neck and main shaft tile, crank neck and connecting rod tile installation clearance should be in accordance with the provisions of Table 5, wear clearance is not greater than two thousandths of the shaft diameter.

3.3.9 Rolling bearings

3.3.9.1 Rolling bearings rolling body and internal and external raceways without pit scars, pitting, corrosion and other defects, the cage is intact, contact smooth rotation flexibility without noise.

3.3.9.2 Rolling bearing disassembly should use special tools or presses. Bearing heating assembly, the oil temperature does not exceed 120 ℃, in the oil bath 10-15 minutes after assembly. It is strictly prohibited to use the flame to heat directly and use the hammer to strike the bearings directly.

3.3.9.3 According to the clearance requirements of the rolling bearing, check the wear with a plug ruler or micrometer or other methods, and replace the rolling bearing when the clearance is greater than the specified value.

3.3.9.4 Check the axial string with a micrometer to see if it meets the requirements, and adjust and replace it if it exceeds the specified value.

3.3.9.5 The fit between the shaft and the inner ring of the bearing is generally H7/K6, and the fit between the bearing and the hole of the bearing housing is generally K7/h6. 3.3.10 Coupling

3.3.10.1 The centering of the coupling should be in accordance with the provisions of Table 6.

3.3.10.2 The clearance between the two coupling halves should be equal in all directions along the circumference, with a tolerance of O.30mm.

4 Commissioning and acceptance

4.1 Preparation for commissioning

4.1.1 Check that the foundation bolts of the base and the connecting bolts between the base and the pump and the motor are tight. 4.1.2 Check the coupling connection.

4.1.3 Check that the amount of lubricant in the bearing box is appropriate. 4.1.4 Check whether the axial seal is pressed too tightly or too loosely.

4.1.5 Check whether the pressure gauge, safety valve, thermometer and other instruments are sensitive and functional.

4.1.6 When the hydraulic cylinder is insulated, check the conveying medium, whether it is liquid or not, otherwise it is not allowed to drive. 4.1.7 Check the intake pipe filter, relief valve is in good condition. 4.1.8 Inlet and outlet valve switch position is correct. 4.1.9 Coil 2-3 weeks, there should be no jams. 4.2 Commissioning

4.2.1 Empty load commissioning

4.2.1.1 After reconfirming the conditions for commissioning, turn on the power supply and start once, if there is no abnormality, then carry out empty load commissioning.

4.2.1.2 Empty load test run should check the equipment operation: a. sound and vibration; b. bearing condition; c. packing seal condition; d. current value. 4.2.2 Load test

4.2.2.1 Running under rated load, there should be no abnormal vibration and noise, and the full amplitude of the pump body is 0.10-0.20mm. 4.2.2.2 The current does not exceed the rated value.

4.2.2.3 The flow rate and pressure are smooth, reaching the nameplate output or meeting the production needs.

4.2.2.4 Seal packing leakage is not more than 10 drops / min. For metering pumps, the leakage is not more than 3 drops / min. There should be no leakage at the sealing point of each connection.

4.2.2.5 Load test pressure should be gradually increased, in the event of abnormalities, should be immediately stopped to deal with, and then retest. 4.3 Acceptance

The overhaul quality reaches the standard of this procedure, and the overhaul records are complete and confirmed. Equipment by the load test run, running well, the main operating indicators to meet the nameplate output or design requirements, you can handle the handover procedures in accordance with the prescribed procedures, delivery of production and use. Third, maintenance and troubleshooting 1 daily maintenance

1.1 Strictly implement the post operation law, carefully fill out the operating records.

1.2 Regularly check the running condition of each part (the temperature of rolling bearing does not exceed 75℃), and record on time. 1.3 Check whether the lubricant level and oil pressure meet the requirements every shift. 1.4 Check each sealing part for leakage every channel. "

1.5 In the freezing season after stopping, the pump should be drained of water and materials to avoid icing damage to parts. 2 Regular inspection content

2.1 Every three months on the lubricating oil quality to make an analysis, check the viscosity of the oil, water, impurities and other changes. 2.2 Monthly check the safety valve, check valve, pressure gauge and other instrumentation is sensitive and reliable. 2.3 Monthly check the vibration of the pump body, the pump body gold amplitude of 0.10-0.20I four It 3 common troubleshooting methods