Servicing of Imperial Diaphragm Manifolds

To service an Imperial® Diaphragm Manifold you will need the following tools:

  • Imperial Overhaul Hit 600R
  • Adjustable Wrench
  • Clean Crease (Optional)
  • Torque Wrench
  • Long Nose Pliers
  • Clean Rags
  • Methylated Spirits or Rubbing Alcohol

Safety is important

  • Ensure work area is clean and well lit
  • Ensure there are no hazards or obstructions
  • Ensure you have safety glasses and put them on NOW
  • Check the manifold is not damaged
  • Check gauges are tight
  • Ensure the sightless (if fitted) has no damage.


Step 1 – Remove the handles

  • Using long-nose pliers gently prise off the knobs and place them in a safe convenient location
  • Check for any damage and replace if cracked


Step 2 – Remove Piston Assemblies

  • Remove all large brass nuts from the manifold
  • Gently pierce the large white diaphragm and remove it
  • Remove the spring and piston which is now removed

Step 3 – Remove All Components from Manifold

  • Your manifold should now be looking like this.
  • Check inside the cutout for the diaphragm seals, ensure there are not scratches or damage inside where the valve seats

Step 4 – Clean Valve Seat

  • Using a lint-free rag soaked in methylated spirits (or rubbing alcohol) clean the valve seat assembly
  • Leave to dry and ensure all alcohol has evaporated


Step 5 – Clean Brass Components

  • Next, disassemble the piston assembly and seal
  • Using a lint-free cloth soaked in a little alcohol clean all the brass components
  • Do this for all remaining piston assemblies
  • Using light crease lubricate the thread of the piston. Do this for all remaining pistons
  • You should end up with all pistons cleaned, brass nuts clean and all parts ready for assembly


Step 6 – Open the Repair Kit

  • Open the 600R kit and remove the components
  • Divide into 2, each kit does 2 valves
  • You should have
    – 2 Diaphragms (1 Thick 1 Thin)
    – A Brass Spacer
    – A Spring
    – A Small Nylon Spring Cap

Step 7 – Start Re-Assembly

  • Place the Spring (Large End Down) into the receptacle in the valve seat
  • Place spring cap on top

Step 8 – Valve Assembly

  • (Optional) Place a small amount of grease onto the edge of 1 face of the thick seal. Place Grease side down into the housing.

Step 9 – Valve Re-assembly

  • Place the thin seal into the receptacle
  • Place the spacer on top of this


  • Next, lightly grease screw thread of piston and insert into large brass nut

  • Ensure piston is fully restricted into the brass nut
  • Place assembly into valve seat and gently hand tighten the large nut


  • Tighten brass nut to 125 inch-pounds with a torque wrench
  • Repeat seal and piston installation and torque all remaining valve port assemblies
  • Check torque again after 24 hours


Last Step – Complete Re-Assembly

  • Finally, replace all knobs back onto piston shafts
  • Gently tighten fully and then loosen pistons
  • Perform cleanup of any excess grease