How Do I Change My Center-Feed Pipe Assembly?
If the press is leaking (around the locknut on the 470-mm size or from the bottom leg drain holes on 630-mm and larger size presses) during the start-up of the feed process, the problem is usually leakage past the center feed quad ring seal. The quad ring may not seal for several reasons.
First check for the root cause:
Did the locknut on the outside of the press head loosen during shipment? If so, tighten the locknut using a spanner wrench, pliers, or pipe wrench.
Was extra field piping and/or manifolding added to the center-feed pipe without proper support? Unsupported loads on the center-feed pipe can cause the pipe to move off axis and unload the quad seal on one side. If this is the case, properly support all external piping. Loosen the piping from the factory supplied piping and/or valve and realign the feed pipe so that it is perpendicular to the plate surface. Tighten the locknut and reinstall the supported piping.
Was the center-feed pipe rotated during the field installation of extra piping/ manifolding? This could unseat the quad seal causing leakage around the seal. No feed pipe movement will reseat it.
Follow these steps to correct it:
Open the press and shift all of the plates to the open position (toward the cylinder head). The inside surface of the head plate will have a centrally located clip nut approximately 0.5“ (13mm) thick that retains the filter cloth on the clip nut seat. This clip nut should be removed with a spanner wrench or pliers.
If the press has non-gasketed plates, lift the cloth off the top cloth pins. If the press has gasketed plates, the cloth must be removed from the caulking groove so that the top 2/3 can be peeled down to expose the center feed and allow the movement of the center feed pipe.
Loosen the locknut and back it off 2 to 3 inches. Carefully push the center feed pipe out of its counter bore in the head plate. This allows access to the quad seal and its mounting land. Reinstall the seal onto the land. A few small drops of super glue may be applied to help retain the seal.
Reinstall the liner pipe into its counter bore and tighten the locknut making sure that the pipe remains perpendicular to the plate.
Reinstall the filter cloth.