Mono M12-25 Grifter 

Spare Parts for M12-25 Grifter

This page lists replacement and compatible spare parts for Mono pumps.
Pump Spares Direct is an independent supplier and is not affiliated with, endorsed by, or authorised by Mono.

Image shown for pump identification purposes only.

Spare Parts List

Select the required parts below to include them in your quote request.

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Select Qty Ref. Part Number Description Material / Spec
Macerator (125 mm) — Wear & Consumable Parts
12M125 3000Cutter Ring (stationary cutting ring)Carbon-chromium tool steel, hardened — grinder wear
14M125 3500Impeller (rotary cutter)Carbon-chromium-moly steel, hardened — grinder wear
113W40533Mechanical Seal (macerator)Carbon / ceramic, oil-lubricated
119M125 4501Shaft Seal Sleeve
118E061 4200ThrowerShaft protection disc
13W40529Torl Seal Ring
15S305360PTorl Seal Ring
117S355351PTorl Seal Ring (shaft oil-seal position)
111M125 4000Seal Retaining Boss
19N845201FImpeller Retaining Nut (left-hand thread)
18M125 4700Lock Washer
Pump Element (CP25) — Wear & Consumable Parts
12M25 2200StatorNitrile rubber — primary wear item
14CP25 2520Rotor316 SS, hard chrome plated — wear item
16MPK-SK011Mechanical Seal Kit (includes torl seal ring)Carbon / ceramic
Pump Element (CP25) — Body, Castings & Drive
11CP11 2400End CoverAcetal copolymer
15CP11 0100Pump BodyAcetal copolymer
112CP25 3210Stub Shaft
113CP25 4700Stator Support Ring
13CP00 0430Plug (fill)
Fasteners & Hardware (Pump Element)
87K113242FHex Head Bolt
88N113102FHex Nut
89W113052FPlain Washer
810W113252FSpring Washer

OEM part numbers are referenced for identification purposes only. Parts listed suit the Mono Grifter M12-25 (125 mm macerator + CP25 pump element; order codes M12B125 / M12B325). Ref. = item number on the OEM exploded assembly diagram. This is a curated list of the most-ordered wear and service parts — the full parts list (macerator inlet flange & hardware, breather, revolution counter, control gear) is available on request. Send your nameplate photo and we’ll confirm the exact part.

OEM part numbers are referenced for identification purposes only.
All parts listed are suitable for use in Mono CP800 pumps.

Exploded Parts Views 

Exploded view shown for reference only. Part numbering may vary by configuration.

Key Technical Specifications 

ParameterValue
Model / BuildGrifter M12-25 packaged pumping station (order codes M12B125 / M12B325)
Station TypePackaged sewage pumping station – 125 mm macerator (grinder) driving a Mono CP25 progressive cavity pump, in a GRP weatherproof kiosk
Pump ElementMono CP25 progressive cavity (single helical rotor / stator), positive displacement
Macerator125 mm rotary cutter / impeller running within a stationary cutting ring
Motor Power0.55 kW
Electrical Supply240V single-phase or 415V three-phase (single or duty/standby control)
Nominal Capacity0.43 L/s (≈1.5 m³/hr)
Maximum Head3 Bar (≈30 m)
Maximum Suction LiftSystem-dependent; ≈3 m at 20 m head (refer to duty / suction-lift curve)
Discharge Connection1" BSP female (package rising main 1½" BSP union)
Valves / Pipework (min. bore)25 mm internal diameter
Direction of RotationAnticlockwise (viewed at the pump end towards the motor)
Macerator MaterialsCast iron body (BS 1452 gr 220/260); hardened & tempered carbon-chromium-molybdenum steel impeller; hardened carbon-chromium tool steel cutting ring
Pump Materials316 S31 stainless steel rotor (hard chrome plated); free-moulded nitrile rubber stator; impact-resistant non-contaminating acetal copolymer body & endcover
Mechanical SealsCarbon / ceramic (macerator seal oil-lubricated, mounted external to process liquid; pump seal carbon / ceramic)
LubricationMacerator oil bath – Rock Oil ISO 100 (or equivalent), level half-way up the sight glass
Weight (Grifter unit)45 kg
Kiosk / PackageGRP kiosk 1528 × 1048 × 590 mm; sump depth 1200 mm (270 kg) or 1600 mm (350 kg)
Noise Level≤70 dB(A)
Suitable DutyNormal domestic / municipal sewage. Not for surface water, flooding, or industrial waste containing glass, bone, metal, scouring pads or excessive rag

Figures are for the Mono Grifter M12-25 (CP25 pump element). Capacity, head and suction lift are system-dependent – confirm against the duty curve for your installation. Order codes M12B125 and M12B325 share this pump element and macerator.

Troubleshooting, Common Faults & Solutions

Static or Rising Liquid Level (Station Not Clearing the Tank)

Likely Cause: Control breaker tripped; incorrect direction of rotation; restriction in the vertical suction pipe or macerator; restriction in the check valve or delivery pipeline; damaged pump element; level control restricted at low level; or a damaged mechanical seal in the macerator or pump

Action / Part: Reset breakers and confirm rotation is anticlockwise (viewed at the pump end towards the motor). Clear the suction pipe by removing plug ‘D’ and rodding, then reseal with PTFE. Inspect the macerator (cutter ring M125 3000, impeller M125 3500) and pump element (stator M25 2200 + rotor CP25 2520); replace worn seals (macerator W40533 / pump MPK-SK011)

Unit Fails to Stop at Low Level

Likely Cause: Float / level switch movement restricted, or accumulated solids on the level switch, cable or tank bottom

Action / Part: Check the float switch moves freely through its full travel; remove any accumulated solids from the switch, cable and tank bottom that could foul it or damage the macerator/pump

Incorrect Direction of Rotation (Critical)

Likely Cause: Supply phased for the wrong rotation on initial start-up or after re-wiring

Action / Part: CRITICAL: correct rotation is anticlockwise viewed at the pump end towards the motor (also arrowed on the macerator body; confirm by the thrower ‘T’ rotation through the slots). If it runs clockwise, STOP IMMEDIATELY and re-wire the supply — running in reverse damages the pump element and can unscrew the rotor. Never run the unit in ‘hand’ where a dry run could occur

Reduced Flow / Poor Maceration

Likely Cause: Worn macerator cutter ring / impeller (poor grinding, frequent blockages) or worn pump stator and rotor (runs but low output)

Action / Part: Inspect and replace the cutter ring (M125 3000) and impeller (M125 3500); replace the pump stator and rotor together as a matched set (stator M25 2200 + rotor CP25 2520). Confirm total discharge pressure is within the pump rating (max 3 Bar)

Leakage at the Mechanical Seal / Oil Leakage

Likely Cause: Worn or damaged macerator or pump mechanical seal (leakage of pump lubricant at the back of the unit indicates a damaged seal)

Action / Part: Check the macerator oil level (half-way up the sight glass; top up with Rock Oil ISO 100 or equivalent). Replace the macerator mechanical seal (W40533) or pump mechanical seal (MPK-SK011). Note: motor or bearing damage caused by a worn mechanical seal is not covered by warranty

High Level Alarm Lit

Likely Cause: Station not keeping up with inflow — any of the “static / rising level” causes above — or an abnormal ‘flash’ inflow

Action / Part: Investigate immediately. Check breakers, rotation, and for suction/delivery restriction; inspect the pump element and macerator for wear. Do not ignore the alarm — serious damage can result if warning lights are ignored

Never Run Dry / Frequent Blockages

Likely Cause: Running dry (immediate damage to the pump element) or unsuitable material in the tank (glass, bone, metal scourers, wet-strength nappies, excessive rag, surface water)

Action / Part: Never run the pump dry — ensure at least 200 mm of liquid in the tank and the delivery valve is open; fill the pump via plug ‘P’ before starting. The Grifter is for normal domestic sewage only; exclude abrasives and surface water to preserve the cutter ring (M125 3000), impeller (M125 3500) and stator (M25 2200)

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