Maintenance Recommendation Nimalike Rev04

7/24/2019 Maintenance Recommendation Nimalike Rev04

http://slidepdf.com/reader/full/maintenance-recommendation-nimalike-rev04 1/3

Maintenance Recommendation:

forNimalike-upgraded valve spindles

1. Item

Upgraded valve spindles (type-standard/Stellite) to Nimalike according MWH-

remanufacturing procedure V05 and V06 (mainly MC series engines).

We provide the following lifetime assurance in diagram form for the Nimalike

remanufactured valve spindles on the basis of the following operations and maintenance

cycles.

2. Operation conditions

The user operates the engine in accordance with the operator’s manual provided by the

engine manufacturer.

The working and maintenance steps described below are carried out and documented by

qualified personnel. The service hours in the following diagram are based on a total of

6.000 hrs/year. According to our experience, the service life (TBO/welding of bottom,

head diameter and seat) of a standard new valve spindle is 12.000 hrs. For Nimalike

upgraded valve spindles the following is applicable:

Operating

hours

0 6000 12000 18000 24000

Working

steps

START A A A B

Remarks Service life

for new

standard

valve spindle

(average)

Service life for

Nimalike upgraded

V05 / V06-valve

spindle (average)

www.mwh.deFile: Maintenance_Recommendation_Nimalike_Rev04.doc



3. Description of working steps

Start: Installation of the remanufactured valve spindle together with a new guide bush,new or reconditioned seat ring and sealing set for the stem in accordance with

the engine manufacturer’s installation manual.

Step A:Dismantling and cleaning of the complete exhaust valve, measuring, inspecting

and documenting the valve spindle and seat ring geometry on the MWH data

record sheet (see annexe).

If the seats show signs of pitting (impression >0.05mms) they must be refaced. We

recommend that this work is carried out in our premises according to procedure V09(valve spindle) and V19 (seat ring).

Figure-1: Signs of pitting > 0.05mm beforerefacing

Figure-2: Seat condition after refacing

www.mwh.de

File: Maintenance_Recommendation_Nimalike_Rev04.doc



www.mwh.de

File: Maintenance_Recommendation_Nimalike_Rev04.doc

If the refinished work is carried out on board , exact compliance with the tolerances and

as little abrasion as possible must be ensured. After the valve spindle and the valve seat

have been ground the new dimensions must be documented accordingly.

The seat geometry must be checked after assembly (with new sealings). It is essential

that there is a line contact between the seat of the valve spindle and the seat ring. The

gap at the external diameter should be 0.1-0.2 mm. This must be documented.

Figure-3: Contact condition of valve spindle seat

Step B: Dismantling and cleaning the complete exhaust valve, measuring, inspection and

documenting the valve spindle and seat ring geometry on the basis of the MWH

data recording sheet (see annexe)

The valve spindle together with all the data collected during the service life must

be brought ashore for remanufacturing according V05 / V06 (valve spindle) and

V11 (seat ring).

4. Complementary Notes

a. All other instructions not given in this recommendation can be followed according to

the engine builders instructions.

b. Refacing the seat of the Nimalike upgraded valve spindles shall be carried out

according to the instructions from the grinding machine supplier for standard/Stellite

valve spindles. The maximum limit for the grinding at each service step A shall not

exceed 0.3 mms.

Documents

Maintenance Recommendation Nimalike Rev04