Learning Center | Lafferty Equipment Manufacturing, Inc.

Pump-Up O-Ring Replacement Guide

Proactive preventative maintenance is important to ensure reliable performance.

Introduction

Pump-Up Foamer and Sprayers operate by using air in the pressurized tank to propel ready-to-use chemical solution. Therefore, it is critical to ensure that the tank is leak-free and all of the connections are 100% sealed. This is accomplished largely using o-rings to seal the gap between the lid and tank, as well as various other areas throughout the unit. These o-rings can decay over time due to normal wear and tear, chemical exposure, physical abuse, or other variables.

Sputtering output is the result of a broken or loose seal somewhere in the unit. The fix could be as simple as tightening the lid or other fittings, lubricating the o-rings regularly with a compatible non-water-soluble grease, or it may become necessary to replace one or more o-rings.

  1. Tools Required
    Tools Required
    • Wrench
    • Small flat-head screwdriver
    • Pump-up repair kit (Viton shown, EPDM available. Select an appropriate seal material based on the chemical in use.)
    • Lubricant – see end of instructions for recommendation
  2. Separate Pump Assembly
    Separate Pump Assembly
    • Pull to separate the shaft from the piston and lid.
    • You will encounter resistance, this is normal. The shaft assembly will “snap” in and out of place.
  3. Umbrella Valve
    Umbrella Valve
    • The umbrella valve is a non-o-ring seal located at the bottom end of the piston.
    • Gently slide the flat-head screwdriver under the edge of the valve.  Do not scratch valve seat.  Pull to remove.
    • Simply snap the replacement into the hole. Ensure that the edges of the valve lay flat and form a good seal.
  4. Piston O-Ring
    Piston O-Rings
    • Gently slide the flat-head screwdriver under the o-ring and grab and pull to remove.
    • Replace with the matching replacement o-ring.
    • Ensure ample lubrication with a non-water-soluble grease.
    • TIP:  Due to friction from pumping, ensure that this o-ring remains well-lubricated.
  5. Main Tank O-Ring
    Main Tank O-Ring
    • Gently slide the flat-head screwdriver under the o-ring and grab and pull to remove.
    • Replace with the matching replacement o-ring.
    • Ensure ample lubrication with a non-water-soluble grease.
    • Reassemble the piston / shaft assembly by snapping the shaft back into the lid.
  6. Air-Relief Valve O-Rings
    Air Relief Valve O-Rings
    • Using a wrench, loosen the pressure relief valve and remove it from the tank.
    • Pull apart the two parts of the assembly.
    • Gently slide the flat-head screwdriver under the o-rings and grab and pull to remove.
    • Replace with matching replacement o-rings.
    • Ensure ample lubrication with a non-water-soluble grease.
    • Reassemble the two parts and reattach the assembly to the tank. Use caution to avoid cross-threading and ensure a snug (but not too tight) fit using the wrench.
  7. Hose Cap O-Ring
    Hose Cap O-Ring
    • Reach into the tank, grab the suction tube, and pull down gently to separate the tube from the cap.
    • Using a wrench, loosen the discharge hose cap and remove it from the tank.
    • This o-ring may be more difficult to access as it is seated deep in the well of the cap.
    • Gently slide the flat-head screwdriver under the o-ring and grab and pull to remove.
    • Replace with the matching replacement o-ring.
    • Ensure ample lubrication with a non-water-soluble grease.
    • Reattach the cap to the tank. Use caution to avoid cross-threading and ensure a snug (but not too tight) fit using the wrench.
  8. Recommended Lubricant
    Molykote 111 Silicone Lubricant
    • Molykote 111 or similar silicone compound.  Ensure that the lubricant is suitable for the chemical and o-ring material.

Refer to the unit Installation and Operation Instructions for troubleshooting, maintenance, and best practices for optimal performance. Note: The EPDM repair kit (blue material) includes additional unused o-rings.

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