Troubleshooting and Maintenance of Air-Powered Pumping Systems

Troubleshooting and Maintenance of Air-Powered Pumping Systems David Kaminski QED Environmental Systems Inc. Ann Arbor, MI / San Leandro, CA Copyright QED Environmental Systems, Inc. 2013-2017; all rights reserved. The information contained within this document may not be published, broadcast, rewritten or otherwise distributed without prior written authorization from QED. Today s Webinar Topics Air-powered pump system components Principles of operation how it works Diagnosing the problem: Look and Listen Common operational issues Safety considerations during pump maintenance Tips on pump removal and installation Pump disassembly tools and tips Cleaning frequency and service life expectations Spare parts and spare pumps save time and $$$ Accessories for improving pump performance 1

2 QED AutoPump AP4+ Pump Components Discharge Head & Air Valve Assemblies Discharge Tube/Float Guide Pump Body (Casing) Float Assembly with Guide Plates Actuator Rod Inlet Valve Assembly and Inlet Screen Air-powered automatic pump: How it works Discharge Cycle When float reaches the top of its travel, exhaust valve closes and air inlet valve opens Air pressure against liquid closes inlet check valve and pushes liquid up discharge tube As liquid level drops, float follows and pulls actuator rod down, closing the air inlet valve and opening exhaust valve to repeat Fill Cycle Fill Cycle Hydrostatic pressure opens inlet check valve As pump fills with liquid, air escapes through exhaust valve and internal float rises

Normal pump operating characteristics 1. Cycling you should hear a release of air pressure when the pump is cycling (exhaust cycle). 2. Pressure gauge if there is a filter/regulator at the well head, you can see a slight drop in the air pressure (5-10 PSI) with each pump discharge cycle 3. Cycle counter the cycle counter should advance a half count in the discharge cycle, then advance a full count with an audible click during the exhaust cycle What if my pump isn t cycling? Determine if the issue is an operating condition in the well or a pump malfunction Examples of operating conditions: Very low well yield (will eventually cycle check counter) Liquid level has dropped below actuation point Air supply pressure insufficient for discharge Excessive discharge line back pressure Examples of pump malfunction Float sticking due to solids buildup, slime, silt Check valve not working due to debris, sand Air valve mechanism plugged or out of adjustment 3

First Step: Look and Listen Look at the well head and connections for an obvious problem broken fittings or loose connections, tubing kinks, etc. Listen for an air leak from a fitting or line at the well cap/flange Look at the air pressure gauge for low or no pressure Listen for a continuous discharge condition you ll hear a hissing sound coming from the pump exhaust line (may be above or below well cap) and/or the liquid discharge line Pump stuck in discharge mode Continuous air from the exhaust line (and sometimes the discharge line) can indicate that the pump is stuck in discharge mode The float may be stuck due to buildup on the discharge tube or debris inside the pump Cleaning will usually resolve the problem, but may require air valve adjustment 4

Pump stuck between cycles If the pump is stuck between cycles, both the air inlet and exhaust valves will be open, allowing air to pass continuously out of the exhaust port (and possibly through the discharge line) called a crossover malfunction Additional evidence: the cycle counter may be stuck between cycle counts Possible causes include an air valve mechanism that is worn (e.g., pivot pin, lever half bushing) or is out of adjustment Cleaning, adjustment or repair may be required to resolve the problem Is liquid level above actuation point? To determine if you have sufficient liquid over the pump to actuate the air valve, you need to know: The installed depth of the pump The pump model and its actuation point The liquid level in the well/riser If the liquid level is above the actuation point and there is sufficient air pressure but the pump isn t cycling, there may be a problem with the pump, such as a stuck float, debris, actuator rod hang-up, air valve issue, etc. 5

6 Pump Actuation Point The point at which the liquid level inside the pump activates the air valve mechanism is called the actuation point The actuation point is the distance from the bottom of the pump to the top of the float travel (top of inlet on top-fill pumps) This distance varies based on pump body length, float length and inlet position and is specified for each pump model The pump position in the well determines the maximum drawdown level in the well How vacuum affects the pump actuation point A vacuum applied to the well (e.g., landfill gas collection, vapor extraction) will RAISE the actuation point above the design point when the pump exhaust is outside the well The increase in the actuation point is based on the amount of vacuum applied to the well, measured in inches (centimeters) of water column (WC) In the example, a vacuum of 20 (51 cm) WC raises the actuation point of the pump from 33 (84 cm) to 53 (135 cm)

How to check if vacuum is preventing the pump from cycling 1. Install a level tape in the well/riser or use a dedicated level measurement system (e.g., bubbler line) 2. Turn off and release vacuum at the well cap/flange 3. Monitor the liquid level and wait for it to begin dropping 4. If the pump starts cycling at the design actuation point, the problem is insufficient submergence under vacuum. Possible solutions: Lower the pump in the well/riser if possible Use a shorter pump model with a lower actuation point If air exhaust is outside the well, change to inside well or install an equalization valve to reference exhaust to vacuum Exhaust air equalization valve Installed in the exhaust line below the well cap/flange with exhaust terminated outside the well Nearly all of the exhaust air is vented through the valve outside the well, with only a small amount of air entering the well when the vacuum reference port opens When exhaust line pressure is equal to atmospheric pressure outside the well, the spring loaded valve closes and allows vacuum to be applied to the exhaust line, allowing the liquid level to be pumped down as low as possible 7

8 Pump not cycling - insufficient air pressure at the well head A pump may not cycle if the air pressure is too low to lift the liquid to the surface or to overcome any header loss or force main back pressure Air-powered pumps need a minimum of 0.5 PSI air pressure for every foot of lift desired plus 1.0 PSI for every PSI of back pressure in the header line Test for low air pressure: increase pressure at well head in 5 PSI increments; pump will start cycling if pressure was too low to overcome lift requirement Test for high header line back pressure: turn off air, disconnect discharge line at header and direct it back into well; pump will start cycling if pressure was too low to overcome header back pressure How to jump start your pump Sometimes a quick jump start can get the pump cycling again when it stalls or sticks (i.e., float hung up) Method 1: remove the air line from the filter/regulator, allow all the air to exhaust from the pump, then reconnect the air line; pump should cycle if sufficiently submerged Method 2: unbolt the well cap/flange and shake the pump system up & down to dislodge the float If the jump start method gets the pump cycling again, it s a good indication that the pump needs to be cleaned, serviced or adjusted to maintain consistent operation and maximum performance

Air Valve Mechanism Adjustment The air valve mechanism should not require adjustment unless it has been repaired or has some wear from long-term use If adjustment is necessary, contact QED for information and instructions based on pump model Air Valve Out of Adjustment (Gap between valve mechanism and pump head) After Proper Air Valve Adjustment Pump maintenance safety considerations Wear appropriate safety gear Safety glasses with side shields or a full face shield (best for liquids) Protective outer clothing (e.g. Tyvek jump suit) Chemically resistant gloves taped at top to prevent leaks Other safety gear required for the site (hi-vis clothing, hard hat, steel toe boots, etc.) Most importantly make sure the pump and all air and discharge lines are not pressurized before you begin any disassembly! 9

10 Shut-offs, check valves and blow-outs Shut off manual valves at the air supply and discharge header to isolate the pump Release any air pressure from the pump If the pump discharge tubing is filled with liquid, you can lighten your load by using the QED Pump Blow-Out Kit (Part Number 40234) to empty the line before lifting the pump Lifting the pump and tubing Wear protective gloves and get a good grip on the tubing or hoses Try to avoid getting kinks in tubing kinks tend to be permanent and can restrict flow or create leaks Use your legs, NOT YOUR BACK! Use a step ladder or tailgate to gain some height and leverage If the system is too heavy to lift, use a winch, crane or automated pump puller

11 Pump Pull-E - faster & safer pump pulls Designed to guide pump tubing out of the well without kinking and to reduce lifting effort to avoid worker injuries Deep-vee roller bolts onto flange or straps to outside of 6 and 8 gas well casings

Keeping debris out of air lines Debris in air lines (dirt, insects, etc.) can clog filter regulators and plug pump air valve poppets Cap or tape end of tubing after pulling the pump to avoid debris Blow out air header lines before connecting pump air supply hoses 12

13 Cleaning air-powered pumps Determining cleaning frequency Cleaning frequency is determined on a site-by-site basis - some sites may go a year or more without cleaning while others may require cleaning as often as monthly or more where high solids or sticky deposits occur If no site history, pull new pumps after 1-3 months of use to gauge need for cleaning or wait for indication of stalling Planned maintenance can be more cost effective than responding to pumps that shut down when dirty

14 AutoPump *AP4+ Designed for easier cleaning Easier disassembly: removing four bolts on bottom inlet allows complete pump disassembly in minutes no turning of the inlet assembly or O-ring hang-up/dragging Easier service: quick-release clip on actuator rod allows quick float removal for easier cleaning. Pump body has a high-polish ID finish to reduce solids build-up and precision bore sizing to improve O-ring fit Increased durability: All metal parts are 304SS or higher for improved corrosion resistance; plastic parts are high-strength & hightemperature engineering plastics (PVDF, PEEK) Increased warranty: 5-year full warranty with no pro-rating in later years * Patent Pending AutoPump AP4+ Design Features New Air Valve Mechanism Design The new captured pin design eliminates need for fasteners, clips or cotter pins at valve stem Improved reliability, easier to service exhaust seat is easier to adjust Now on all AP4 models!

15 Introducing the first low-maintenance air-powered pump: The Ultra lasts up to 10 times longer between cleanings and takes up to 50% less time to clean The Ultra combines all of the design features and rugged reliability of the AutoPump AP4+ in an innovative design that reduces build-up of solids and sticky deposits on the float and center rod Greater reliability in challenging applications Fewer pump pulls for maintenance Cleaning is faster and easier Design Features Non-stick float and electro-polished center rod reduce solids buildup, low-friction engineered plastic guide plates reduce pump stalling All metallic parts are 316-grade SS for greater corrosion resistance and reliability Non-stick, high polish finishes make cleaning easier can be as easy as wipe and rinse

16 Field testers compared the new AutoPump Ultra to existing pumps and reported the following results: Maximum uptime Minimum Downtime Teardown and cleaning took absolutely no effort No soaking required Only needed a water spray to clean Removed residue with some clean water and the swipe of a hand Easier to clean by 50% It s been running for four months and I haven t had to clean it yet! Ultra pump test pulled in October 2015 after one year

17 Annual Pump Cleaning Savings with AutoPump Ultra Standard Pump AutoPump Ultra Cleaning Frequency Pump Pulls/Year AP Ultra Frequency Pump Pulls/Year Annual Pulls Saved Savings @ $100/pull Savings @ $150/pull Savings @ $200/pull 4 weeks 13 18 weeks 3 10 $ 1,000 $ 1,500 $ 2,000 2 weeks 26 8 weeks 7 19 $ 1,900 $ 2,850 $ 3,800 2 weeks 26 22 weeks 3 23 $ 2,300 $ 3,450 $4,600 1 week 52 19 weeks 3 49 $ 4,900 $ 7,350 $ 9,800 Using the AutoPump AP4 Ultra and reducing your cleaning frequency from monthly to quarterly at $100 per cleaning event saves $800 annually and frees up as much as 16 hours of technician field time AP4 Ultra Calculator Tool QED s latest calculator tool helps you find your potential pump maintenance time and cost savings using the AP4 Ultra pump Set up for both in-house maintenance and contractor doing field O&M work The calculator will display the time savings or cost savings against alternative air-powered pumps Find it at qedenv.com/ultracalc

18 AutoPump AP4.5 Ultra Greater Clearance = Lower Maintenance Incorporates all of the lower-maintenance features of the AutoPump Ultra into a wide-body design with increased internal clearances better handling of solids, precipitates and sticky deposits Larger discharge volume per cycle = less wear, longer service life Greater clearances further reduce cleaning frequency by 3x 5x or more Standard AP Ultra AP4.5 Ultra AutoPump AP4.5 Ultra Greater Clearance = Lower Maintenance Design features Increased clearance between float and discharge tube from 0.144 to 0.437 (3x greater) Increased area between float and casing to 0.437 0.5 gallons (1.9L) per cycle Overall dimensions: 4.6 OD x 39.9 long (11.6 cm x 101 cm) Applications Primary application in LFG well dewatering and vertical landfill leachate risers Minimum well diameter is 6 (150mm) ID AutoPump Ultra AutoPump AP4.5 Ultra

Getting the right tools QED offers a complete tool kit for AP4 pumps Double pin spanner to remove threaded inlet Honing tool to remove hard deposits from pump body Casing removal tool, punch and Allen wrench Optional pipe vise with rubber jaws to hold pump body What about tools for the AP4 Plus? The newly redesigned AP4+ has a bottom inlet design that comes off easily by removing three small bolts no need for the spanner or casing tool! The honing tool and pipe vise (if desired) can be purchased separately AP4 Service Tool Kit 19

20 Cleaning agents and supplies Degreasing agents such as Simple Green or Detergent 8 can remove oily or slimy deposits Scouring pads can remove about 90% of bio-growth and buildup on pump parts (but avoid float damage!) Use brush kits with extended handle to clean inside the pump body and discharge tube Cleaning agents for scale buildup Cleaning solutions such as CLR or common acids such as citric acid and vinegar (acetic acid) can help remove heavy mineral deposits and biorock avoid hydrochloric or sulfuric acids Do not leave metal parts in strong acids overnight! Don t clean acetal (Delrin ) plastic parts with acids it can weaken/damage them NEVER mix acids with other cleaning solutions ALWAYS rinse other cleaners away first to avoid dangerous (and potentially fatal) chemical fumes

Spare parts for field repairs Spare parts needed will vary by pump model, but most require only a handful of parts The quantity of spare parts you will need is dependent on the size of your site and how many pumps you have QED Customer Service can help you with recommended parts for your pumps, such as check balls, O-rings, fittings and springs Spare pumps = major cost savings When labor for cleaning or repairs exceeds 30-60 minutes, having one or more spare pumps can save considerable cost over immediate field repair Less downtime, especially valuable in LFG wells Maintenance can be done in the shop or by the manufacturer rather than under field conditions No need to stock every necessary spare parts Shipping for parts or pump repairs can be done at economy rates rather than overnight shipping 21

22 Accessories to improve performance and reduce maintenance in tough applications Silt and Foam Filter Designed to reduce solids loading in pumps to improve performance and extend maintenance intervals Threads into pump inlet assembly (replaces standard inlet screen, requires a modified inlet assembly) Filter pad material can be cleaned or replaced Can also improve pump performance and reduce leachate emitting from external exhaust line in wells with foaming leachate Accessories to improve performance and reduce maintenance in tough applications Wide Slotted Float Can improve performance in wells with silt or where solids deposit on pump components Actuator rod slot is wider for greater clearance between rod and float Now standard on AP4+ models Can be retrofit to existing AP4+ pumps (contact QED Customer Service for details) Standard Float Wide Slot Float

23 Accessories to improve performance and reduce maintenance in tough applications Wide-Slot Float with Non-Stick Coating Entire float assembly is coated with a proprietary non-stick coating Greatly reduces build-up of solids on the float, which can extend maintenance intervals Speeds cleaning and reduces chance of damaging float during cleaning Replaces Teflon-wrapped floats for applications with sticky deposits or high dissolved solids Standard on AP4 Ultra; can be retrofit to existing AP4+ pumps contact QED for details Easy Fittings faster and safer Maintenance often requires removing pump tubing Cutting tubing and clamps from barb fittings can be difficult, time consuming, poses a safety risk, and shortens tubing length 2-3 (5-8 cm) each time Easy Fittings are high-flow quick connects with quick-release retainer clips Made of high-quality stainless steel alloys with double Viton O-ring seals Saves valuable field time and cost LESS than conventional quick-connect fittings

24 Stand tubes for pump testing A stand tube should be used to verify that a pump is working before you send it back down the well to avoid pulling it again if it s still not working You can make a stand tube from a piece of 4-inch diameter PVC pipe or well casing about 5 feet long, with a flat threaded cap or plug at the bottom PVC is very inexpensive, holds up well to most cleaning solutions and leachates A stand tube can save HOURS of lost time if you find that a pump isn t working properly before it s installed Pump service life expectations Pump service life is dependent on operating conditions of each well (chemistry, temperature, solids, etc.) and proper materials selection for the application The biggest factor you can control is pump maintenance. Many QED pumps have been in use for 12-15 years and are still operational due to regular maintenance 90% of all pump maintenance is cleaning, not repairs

25 Some applications are a bit more challenging than others, but with proper selection of pump model and materials, good installation practices and adequate preventative maintenance, air-powered automatic pumps can handle some of the toughest pumping application seen at landfill and remediation sites with longer service life than other pump designs. Questions? QED Environmental Systems, Inc. E-mail: info@qedenv.com Toll-Free Numbers Ann Arbor, MI: 800-624-2026 San Leandro, CA: 800-537-1767 Website www.qedenv.com