Pump and Valve Components and Maintenance

Transcription

1 Pump and Valve Components and Maintenance Outline: 1. Split case and End Suction pumps, industry in the 21 st century, cost of ownership, and performance tips 2. Split case Pumps features, maintenance, and start up 3. End Suction Pumps features, maintenance, and start up 4. Methods of Pump Alignment 5. Vertical Turbine Pumps features, maintenance, and start up 6. Valves; Types and difficult maintenance

2 Split Case Pumps & End Suction Pumps Industry and Equipment Changes, Performance & Modifications

3 Pump industry in the 21 st century Trends Information age Service economy Rise of the knowledge worker Implications for pump industry Easier access to data on pumps, pump accessories and pumping systems. Use of world wide web. a) Increasing relevance of pre and post purchase services, software associated with the product. b) Emergence of a variety of new services design & development, retrofit & energy audit, specialized maintenance, condition monitoring etc. a) Sales engineers act as consultant to clients. b) Value addition by knowledge workers in system engineering, equipment selection, pump installation and commissioning, condition monitoring, retrofit, etc.

4 Pump industry in the 21 st century Trends Implications for pump industry Age of the smart machines Increase in trust and alliances a)pumps that learn on the job. b)pump selection, application & training program. c)availability of condition monitoring tools and satellite communication. a)collaborative efforts between users and manufacturers of pumps. b)increasing use of single source procurement by major pump users. Age of mass customization Ability to customize pumps quickly and at low cost for specific applications provides competitive edge.

5 Pump product continuum and shift in strategic emphasis Domestic pumps Agricultural close coupled pumps DIN End Suction pumps ISO 2858 End Suction Pumps Standard split case pumps Standard vertical wet pit pumps Engineered split case & Wet pit pumps. Boiler feed & extraction pumps Product range optimization Tender optimization Integrated excellence Task Group excellence Little or no interaction with user Protracted Interaction Design & development skills Application engineering skill Large batch manufacturing Customized manufacturing Back room marketing Customer focused selling

6 Advantages Split Case & End Suction Pumps Inspection of internals without disturbing the pipework and the bearings. Simpler maintenance lower maintenance downtime Balanced axial thrust load for Split Case

7 Importance of efficiency a. Life cycle cost 5% 10% Initial cost Maintainance 85% Operating cost Capitalized cost of one unit difference in efficiency is equal to the price of the pump.

8 Reasons for sub-optimal performance Specification related System related Inaccurate capacity, head, NPSHA & range of operation specified. Change in demand Change in system components Change in sump/suction condition Change in application Effects of sub-optimal performance 1. Increased power consumption. 2. Increased level of noise and vibration. 3. Cavitation erosion. 4. Shaft / bearing failure. 5. Declining performance.

9 Effect of modification to pump internals LOCATION MODIFICATION EFFECT Volute throat Cut back Improves capacity and efficiency Impeller outlet Undefiled vanes Improves head at BEP Impeller inlet Cut back vanes Improves NPSHR Impeller diameter Wear rings Vane passages Impeller width No. of vanes Reduce Restore clearance Clean/Polish/Coat Increase Decreases Change in performance as per affinity law Improves efficiency particularly in low NS pumps Improves efficiency in low NS pumps Flattens curve and increases capacity Steepens curve and moves BEP down and to left

10 Split Case Base Mount Pumps Split Case, Double Suction, Pumps Components of Construction and Inspection Tips

11 Features and Benefits - SCP Horizontal Split Case, Double Suction Design Simple access to rotating assembly Hydraulically balanced Highest efficiency of any pump type Uses NEMA Frame Foot Mount Motors (Any Mfg s OK) All voltages and enclosures available. Various efficiency types and VFD compatible versions available Metric Free???? All tappings NPT (gauge and gland drain) Know what your buying, metric is OK if your prepared for it ¼ Pressure Gauge Tappings Standard Suction and discharge most all manufacturers

12 Detailed Technical Features Horizontally split casing - enables replacement of bearings and mechanical seals without disturbing system piping Internal flush water insures maximum seal life (Copper or SS tubing for Long Life) Re-greasable bearings, Double row ball bearing on non-drive end. Thrust End or OB End Impeller double suction (hydraulically balanced), minimizes axial thrust Tongue & groove case ring design eliminates axial displacement and seizure of rotating assembly Double lock nut and key arrangement ensures reverse rotation of shaft sleeve

13 Detailed Technical Features Short shaft sleeve Keyed Impeller Nut 13

14 Features & Benefits Easy maintenance Split case concept : - The top casing can be removed, in order to have direct access to the rotating parts. Reduced maintenance downtime Material information Casing : - Standard construction in Cast iron - Alternative materials available (Bronze, Stainless Steel ). 14

15 Features & Benefits Easy maintenance Tong & groove wear rings. - To guarantee a correct location on reassembly. - To avoid wear on the casing. -Minimise bypass from suction to discharge Longer seal lifetime Controls cavitation Material information Wear rings : - Standard construction in Bronze. - Alternative materials available 15

16 Features & Benefits More reliable Double suction concept. - The impeller are hydraulically balanced so axial thrust is minimised. - To minimised the NPSHr Axial thrust Axial thrust More reliable Material information Impeller : - Standard construction in Bronze. - Alternative materials available (Cast iron, Stainless Steel ). 16

17 Features & Benefits Lifetime extended Between bearing concept. - To reduced shaft deflection. - To minimised vibration. - Bearings can also be removed without disturbing top casing. Longer bearing and seal lifetime Material information Shaft : - Standard construction in Stainless Steel. - Alternative materials available 316 SS, Duplex SS 17

18 Features & Benefits Lifetime extended Seal return pipes. - To avoid premature wear of the mechanical seal or packing. - For abrasive fluid use a cyclone separator in the stuffing box. Longer seal lifetime Material information Seal return pipes : - Standard construction in Copper. - Alternative materials available 18

19 19 Erosion Damage / Grit and Debris in Water

20 20 Pump Fitted with Mechanical Seal

21 21 Cavitation Damage on Inlet Vanes, Repaired & Polished

22 22 Case Wear Ring Fits must be sharp and clean

23 23 Packing Sleeve, Worn completely through into shaft due to over tightening and neglect.

24 24 Heavy Cavitation Damage due to weak NPSHR

25 25 Sometimes its necessary to line bore internal pump fits to restore efficiency.

26 26 New Sleeves, Wear Rings, Machined Case Fits, Rotor Being realigned into casing.

27 Proper Piping for Suction Side of a Split case Pump There is always an uneven turbulent flow round an elbow and when it is in a position other than vertical it causes more liquid to enter one side of the impeller than the other. This results in high un equal thrust loads that will overheat the bearings and cause rapid wear in addition to affecting hydraulic performance. 27

28 28 Improper Flow to Suction Eye s of Split Case Pump

29 29 Questions/Comments?

30 End Suction Base Mount Pumps End Suction, Centerline Discharge Base Mount Pumps Components of Construction and Inspection Tips

31 Features and Benefits - NL Radically Split, Back Pullout Design Repair wet end without disturbing piping Uses NEMA Frame Foot Mount Motors (other Mfg s OK) All voltages and enclosures available. Various efficiency types and VFD compatible versions available Metric Free All tappings NPT (gauge and gland drain) Know what your buying, Metric is OK if your prepared for it. ¼ Pressure Gauge Tappings Standard Suction and discharge

32 Detailed Technical Features Shaft Sealing : Mechanical Seal For temperature (-4 F to 250 F)

33 Detailed Technical Features List Of Components Volute Casing Casing Cover Support Foot Shaft Impeller Ball Bearing Bearing Bkt Mech. Seal Stuffing Box Shaft Sleeve (Stuffing Box)

34 Detailed Technical Features Conical seal chamber Avoids vortex formation Reduces the possibility of pressure drop in Mech seal area Anti-Rotation rib 34

35 Clean Intake screens for Raw Water Pumps are Important 35

36 Proper Piping for Suction Side of End Suction Pump Eccentric reducers should be installed directly at the suction nozzle, with the taper at the bottom to prevent air pockets from forming. Straight taper reducers should never be used in a horizontal suction line because of the air pocket that is formed at the leg of the reducer and the pipe. 36

37 37 Proper Piping Position Using Eccentric Reducer

38 Split Case Pumps & End Suction Pumps Three Methods of Proper Alignment

39 Method #1:Dimensional Alignment Step 1: Angular Alignment To check angular alignment: Insert a feeler gauge or taper gage at any four places 90 apart around the coupling halves. Insert shims under the driver feet until the same reading is obtained at all four check points. The pump and driver will then be in angular alignment. 39

40 Step 2: Parallel Alignment To check parallel alignment: A straight edge should be held against the edges of the coupling halves at any four places 90 apart around the coupling. The straight edge should be parallel to the pump and driver shafts at all times. Insert shims until the straight edge lies flat against both coupling halves at all four checkpoints. The pump and driver will then be in proper parallel alignment 40

41 41 This Method is the Least Accurate but Better than no Alignment at all!

42 Method #2: Dial Indicator Alignment Step 1: Dial Indicator Angular Alignment To check angular misalignment: Mount the dial indicator base to the coupling half, and position the dial indicator button on the front or rear face of the opposite coupling half. Set the dial to zero, rotate both coupling halves together, making sure the indicator button always indicates off the same spot. Misalignment values within inches TIR per inch of coupler radius is permissible. 42

43 Step 2: Dial Indicator Parallel Alignment To check parallel misalignment: Mount the dial indicator base to one coupling half, or shaft and position the dial indicator button on the outside diameter of the opposite coupling half. Set the dial to zero, rotate both coupling halves together, making sure the indicator button always indicates off the same spot. Misalignment within inches TIR is permissible 43

44 44 Much more accurate than the manual method but does not compensate for indicator droop.

45 45 Method #3: Laser Alignment Easiest & Most Accurate

46 General Recommended Safety Precautions of both Split Case & End Suction Pumps Do not throttle the suction line to adjust the pump output. Do not operate pump without all guards in place. Do not run pump dry, seal and packing damage may occur. Do not let heated pump temperature rise above 150 F taken on external surfaces. Disconnect and lockout power before servicing. Make certain the internal pressure is relieved before performing any service. 46

47 Before Initial start of the pump, make the following inspections Check alignment between pump and motor. Check all connections to motor and starting device with the wiring diagram. Check voltage, phase, and frequency on motor nameplate with line circuit. Check suction and discharge piping and pressure gauges for proper operation. Turn pump shaft by hand to assure that it rotates freely. Check driver lubrication. Assure that pump bearings are properly lubricated. Assure that coupling is properly lubricated, if required. Assure that pump is full of liquid ( PRIMING ) and all valves are properly set and operational, with the discharge valve closed, and the suction valve open. Check rotation. Be sure that the drive operates in the direction indicated by the arrow on the pump casing as serious damage can result if the pump is operated with incorrect rotation. Check rotation each time the motor leads have been disconnected. 47

48 48 Questions/Comments?

49 49 Vertical Turbine Pumps Used for Raw Water and High Service

50 50 Pre Assembled Pumping Skids

51 51 Small Diameter Units For Moving Water Through the Plant

52 52 Large Diameter Units For High Volume Feeds

53 53 Standard Construction Components

54 54 Hollow & Solid Shaft Connection to Driver

55 55 Impeller Adjustment - Hollow Shaft

56 56 Impeller Adjustment Solid Shaft

57 Impeller Running Clearance Adjustment Running clearance of an Open style impeller is critical, the entire performance of the pump and its ability to run at its Best Efficiency Point [BP] depends on it. Refer to the OEM for this clearance dimensions. Running clearance of a closed or shrouded impeller is also important, however its BP is based on the Diametric clearance between the impeller ring and the bowl ring. All settings must allow for shaft elongation based on the length and weight of shaft and the temperature of the water being pumped. Refer to the OEM for this calculation. After setting the Running Clearance you should be able to turn the pump with relative ease to verify there is no rubbing. Packing tension and the weight of the driver and pump assembly will have an affect on this. 57

58 Impeller Running Clearance continued On larger pumps it is possible to read AMP draw on each phase and look for a pulsation in the readings, this could indicate a rub while under power not felt when turning assembly by hand. 58

59 Pump Pre-Start Check List Check wiring connections to driver. Check voltage, phase, and frequency of circuit with name plate on driver Check for proper lubrication on Driver, reference the OEM Check Impeller adjustment Inspect packing gland for adjustment. Check flush piping & validate water flow. Check for proper rotation efore connecting driver coupling. Reference OEM for direction of rotation. Inspect all piping connections and piping supports. Install pressure gauge on discharge. Check water level in sump for proper submergence of the suction end. Not enough water could cause vortex or cavitation. 59

60 60 I Repeat; Keeping Intake Screens In Place Is Important.

61 61 Bushings and Shafts Worn to One Side Indicate a Pump Out of Level, Out of Balance, or Assembled Incorrectly

62 62 Improper Maintenance or Lubrication of Packing can Destroy Shafts

63 63 Abrasives in Pumped Media or Improper Flush Pressure to Enclosed Line Shaft can Cause Scoring & Heat Damage

64 64 Questions / Comments

65 Common Types of Valves Butterfly Plug Check Ball Cone Gate 65

66 Complexities of Valve Maintenance How Hard Is It??? The majority of water plant valve failures is caused by 1 or more of the following 66

67 Not Hard At ALL Step 1: Lubricate all moving components to OEM recommended intervals Step 2: Replace packing and soft goods when they start to leak, NOT years later. Step 3: EXERSISE! EXERSISE! EXERSISE! EXERSISE! 67

68 THANK YOU I thank you very much for your attention. If you have any further questions please don t hesitate to contact me. Matt Glova: Industrial Pump & Valve Repair ANY QUESTIONS?? 68