Filter Elements — Quick Reference (English)

Items: PH718-05-CB· PH718-05-CN

Location: Heavy cast-steel head, mounted between pump and valves (pressure leg).

Family / Size: PH718 housing, -05 length class (same height/OD — the two spares differ only by bypass option, not by length).

1) At a Glance (the only difference that matters)

⚠️ CB vs CN is a functional choice, not a cosmetic one.

They look almost identical side-by-side. The only safe way to keep them apart is the label on the box/element + the housing nameplate, not memory.

2) What to Check Before You Fit Either One

• Read the metal nameplate on the filter head (near the inlet/outlet ports):

  it must show PH718…, max working pressure (often up to 350–420 bar class), port size/type, and a FLOW ARROW.

  
  

• Old element: quick ruler check — same height / OD / centre-hole (confirms “-05”).

  
  

• Seal colour: these are normally black/dark grey (NBR).

  If the old O-ring is brown/red, stop — the housing may be specified for a higher-temp compound and you’ll need the correct variant, not “CB/CN as-written.”

  
  

3) Replacement — Pressure-Side (Safety First)

1. Close upstream isolation if fitted → bleed slowly at the head vent until the gauge reads 0 and all hissing stops.

   
   

2. Support the bowl — this is heavy cast hardware; don’t let it hang on the piping.

   
   

3. Release the retainer → lift the element straight out (follow the arrow on the head; some PH pull up, some pull down).

   
   

4. Check the bowl bottom for bright metal shavings (pump/valve wear signal — report it).

   
   

5. Wipe sealing faces → thin film of clean hydraulic oil on the O-ring (no grease, no sealant).

   
   

6. Seat the new element square on the centre support (off-centre under pressure = bypass or crush risk).

   
   

7. Reassemble → torque evenly → close vent.

   
   

8. Bring pressure up slowly → stay close for the first minutes and watch for leaks.

   
   

4) Procurement — What to Write (so Stores can’t “almost” it)

• PH718-05-CB

  → Element for PH718-05 housing, with internal bypass (CB). Supply exact match confirmed against the head nameplate model; require OD / height / centre bore / seal compound before delivery. No “same-size” substitute.

  
  

• PH718-05-CN

  → Element for PH718-05 housing, non-bypass/closed (CN) version. Same rule — confirm against the head nameplate; do not swap CB↔CN unless the equipment spec and the head’s own bypass arrangement explicitly allow it.

  
  

5) One-Line BOM (copy-paste)

• PH718-05-CB— Pressure-line element, PH718 -05 class, with internal bypass (CB), fits PH718 head nameplate only — depressurize fully before opening

  
  

• PH718-05-CN— Pressure-line element, PH718 -05 class, non-bypass/closed (CN), fits PH718 head nameplate only — depressurize fully before opening

  
  

One rule that keeps crews safe

On pressure legs: bleed until the gauge is zero, not until “it looks calm.”

And if an element’s ∆P light/alarm keeps coming back soon after replacement, the problem is usually system contamination, not the element — opening a pressure filter repeatedly without cleaning the tank/offline loop just wears out spares.