RPDA 4AN21/2” – 6”

Modification OverviewModification Overview

Production of the RPDA 4AN series began in Production of the RPDA 4AN series began in 2008.2008.

The 4AN indicates an “N” shaped pattern.The 4AN indicates an “N” shaped pattern.

The RPDA 4AN can utilize either a Type I or The RPDA 4AN can utilize either a Type I or

Type II bypass.Type II bypass.

A Lead free version (4ALF) was introduced in A Lead free version (4ALF) was introduced in 2011.2011.

Check Cover RemovalCheck Cover Removal Cover is secured by a Cover is secured by a

V-band clamp and o-V-band clamp and o-ring sealed.ring sealed.

To remove clamp, To remove clamp, loosen lock nut until the loosen lock nut until the latch can be disengaged latch can be disengaged from the T-bolt.from the T-bolt.

Cover has no spring Cover has no spring load.load.

A flat screwdriver will A flat screwdriver will help pry the lid from the help pry the lid from the body.body.

Check Valve Removal Check Valve Removal

Check valve modules Check valve modules are secured by a are secured by a spacer and o-ring spacer and o-ring sealed.sealed.

Remove the spacer Remove the spacer from the body.from the body.

Pull the module Pull the module straight out of the straight out of the body.body.

Check Disc ReplacementCheck Disc Replacement

Remove the lock nuts Remove the lock nuts and the retaining plate and the retaining plate on the back of the on the back of the module.module.

** Do not remove any ** Do not remove any hardware from the hardware from the spring side of the spring side of the module.module.

Separate the disc Separate the disc retainer from the retainer from the module.module.

Check Seat RemovalCheck Seat Removal

The check seat is part The check seat is part of the check module of the check module and can not be and can not be removed.removed.

If the seat is If the seat is damaged, the damaged, the complete check complete check module will need to module will need to be replaced.be replaced.

Check Valve Reassembly NotesCheck Valve Reassembly Notes

Reassemble check Reassemble check modules in reverse modules in reverse order.order.

Do not over tighten Do not over tighten the lock nuts.the lock nuts.

Check Valve Reassembly Check Valve Reassembly

Lubricate check Lubricate check o-rings.o-rings.

Push modules Push modules straight into body.straight into body.

Insert spacer into Insert spacer into body.body.

Replace access Replace access cover.cover.

RV Cover RemovalRV Cover Removal Cover is secured by a Cover is secured by a

V-band clamp and V-band clamp and sealed by the sealed by the diaphragm.diaphragm.

Remove sensing line.Remove sensing line. To remove clamp, To remove clamp,

loosen lock nut until loosen lock nut until the latch can be the latch can be disengaged from the disengaged from the T-bolt.T-bolt.

Pull cover from body.Pull cover from body.

RV Stem RemovalRV Stem Removal

Remove the RV Remove the RV module by grasping module by grasping the diaphragm plate the diaphragm plate and pulling straight and pulling straight out of the body.out of the body.

RV Seat RemovalRV Seat Removal

The seat is pushed The seat is pushed into the body and into the body and o-ring sealed.o-ring sealed.

Simply pull the Simply pull the seat straight out of seat straight out of the body.the body.

RV Disc ReplacementRV Disc Replacement

Holding the module in Holding the module in one hand, remove the one hand, remove the bolt and washer.bolt and washer.

Remove the seat Remove the seat disc.disc.

Disassemble RV ModuleDisassemble RV Module

Module is spring Module is spring loaded.loaded.

Holding the Holding the diaphragm plate diaphragm plate firmly, remove the firmly, remove the retaining bolt.retaining bolt.

Disassemble RV ModuleDisassemble RV Module

Remove the bushing Remove the bushing from the stem.from the stem.

Remove the stem Remove the stem o-ring.o-ring.

RV Reassembly NotesRV Reassembly Notes

Replace and lubricate Replace and lubricate o-rings.o-rings.

Reassemble in Reassemble in reverse order.reverse order.

Push module straight Push module straight into body.into body.

Make sure the outer Make sure the outer edge (bead) of the edge (bead) of the diaphragm fits into the diaphragm fits into the groove on RV body.groove on RV body.