Hydraulic Filter Elements — Quick Reference (English)

Items: PH31211CG· PH414-05-CGVRF

1) PH31211CG— Pressure-Line Filter Element

(on most housings the printed code reads with dashes as PH312-12-CG; the sticker just merged it as PH31211CG)

What it is

A disposable pleated filter element in a heavy cast-steel head on the pressure leg (between pump and valves).

• PH312 = pressure filter family (often up to ~350–420 bar class)

  
  

• 12 (or occasionally “11” if your specific head is the 11-length) = length/dirt-holding class

  
  

• CG = C = NBR (black/dark grey O-ring, mineral oil) + G = end-cap/structural variant — keep the “G” when you order; dropping it can bring the wrong centre locator.

  
  

⚠️ If the removed O-ring is brown/red, stop and confirm the fluid/temperature spec before fitting any “CG” spare.

Safety first (pressure side)

1. Close upstream isolation if fitted → bleed slowly at the head vent until gauge reads 0 bar and no more hissing.

   
   

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

   
   

3. Release the retainer → lift element straight out (follow the flow arrow on the head).

   
   

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

   
   

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

   
   

6. Seat 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 and watch for leaks.

   
   

Procurement wording (safe)

“PH31211CG (= PH312-12-CG) — Pressure-line element for PH312-family housing (12 length class, CG variant). Supply exact match confirmed against the head nameplate model; require OD / length / centre bore / seal compound before delivery. No ‘same-size’ substitute.”

2) PH414-05-CGVRF— Pressure-Line Filter Element (Different Length / Variant)

What it is

Also a pressure-leg disposable element, but this one is the PH414 family, and 05 means a shorter/smaller-dirt-holding length than the 12-class cans.

• CGV… / RF = bundled seal & bypass/end-cap variant (the “V/RF” portion often signals a higher-temp or FKM-related nuance — if the old O-ring looks brown/red, treat it as Viton-type and don’t force a plain black NBR “C” by guess).

  
  

What to check before fitting

• Head nameplate near ports: must read PH414…, MAX WP (bar/MPa), port size/type, and a FLOW ARROW.

  
  

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

  
  

• O-ring colour: black/dark grey = NBR base; brown/red = likely Viton — match exactly.

  
  

Replacement steps

Same pressure-side sequence as above:

isolate → bleed until 0 → support bowl → straight pull → inspect shavings → thin oil on O-ring → seat square → even torque → slow pressure-up → watch leaks.

Procurement wording (safe)

“PH414-05-CGVRF — Pressure-line element for PH414-family housing (05 length class, CGVRF variant). Confirm against head nameplate; require OD / length / centre bore / seal compound before delivery. Do NOT swap with PH312-12-CG just because both are ‘PH3xx pressure cans.’”

3) Quick Field ID (Don’t Mix PH312 ↔ PH414)

One-Line BOM (copy-paste)

• PH31211CG— Pressure-line element, PH312 family (12 length, CG), fits PH312 head nameplate only — full depressurize, support bowl, seat square, pressure up slow

  
  

• PH414-05-CGVRF— Pressure-line element, PH414 family (05 length, CGVRF), fits PH414 head nameplate only — same rule, not interchangeable

  
  

One rule that covers both

Bleed until the gauge is zero, not until “it looks calm.”

After that it’s always the same three things: square seating → clean O-ring → pressure up slow.

If the nameplate paint is flaked, write the ruler height (mm) of the old element on the BOM line — that alone stops every “PH3xx mix-up.”