Multitech 1777.8/7-10 G3 Multitec Servicing / maintenance, Bearings and lubrication, Pump

Multitec

7 Servicing / maintenance 7.2.2 Bearings and lubrication

7.1General instructions

The operator is responsible for ensuring that all maintenance, inspection and installation work be performed by authorized, qualified personnel who are thoroughly familiar with the manual.

A regular maintenance schedule will help avoid expensive repairs and contribute to trouble-free, reliable operation of the pump with a minimum of maintenance expenditure and work.

Before commencing any work on the unit, always make sure that the drive unit (electric motor, turbine, I.C. engine, ...) cannot be started up.

Pumps handling liquids posing health hazards must be decontaminated. When draining the fluid pumped see to it that there is no risk to persons or the environment.

All relevant laws must be heeded.

7.2Servicing / Inspection

7.2.1 Supervision of operation

Caution The pump must run quietly and free from vibrations at all times.

The pump must never be allowed to run dry. Max. permissible room temperature 40 ￿C.

The bearing temperature may exceed room temperature by up to 50 ￿C, but must never rise above 90 ￿C (measured on the outside of the bearing bracket), see also section 7.4.4.1.

Do not run the pump against a closed shut-off valve for prolonged periods of time so as to avoid heating up of the

fluid pumped.

Caution: For required minimum flows please refer to section 6.2.3.

During pump operation the shut-off valve in the suction line must not be closed.

The mechanical seal shows only slight or invisible (vapour) leakage during operation. It is maintenance-free.

Gland packings must leak slightly (individual drops).

Any stand-by pumps installed shall be switched on and then immediately off again once a week to keep them operational. Attention shall be paid to the correct functioning of the auxiliary connections.

On grease-lubricated units, the rolling element bearings of the MTC32 and the non-drive end rolling element bearings of the MTC50 and MTC65 in design C and D are lubricated for life and do not require re-lubrication. For this reason, no lubricating nip- ples are provided on the bearing brackets.

Pump

Depending on the pump version, the rolling element bearings are either grease-lubricated or oil-lubricated.

Grease quality / Grease change

The bearings are packed with high-quality lithium-soap grease. Depending on the size and the operating hours of the pump, the rolling element bearings must be re-lubricated or the grease in the rolling element bearings must be replaced.

		Speed (1/min)
Size MTC	< 1800	￿ 2950	￿ 3550
32-50-65	10000h	7200h	5700h
100-125	9000h	5700h	3900h
150	8300h	4000h	3100h

If re-lubrication intervals are short, we recommend to completely replace the grease once a year. If this is not the case, the grease fill must be replaced completely at least every two years. For this purpose, the rolling element bearings must be removed, cleaned and packed with new grease.

Under unfavourable operating conditions, e.g. high ambient temperature, high atmospheric humidity, dust-laden air, aggressive industrial atmosphere etc., the bearings shall be checked earlier and cleaned and packed with new grease, if required.

Use a high-quality lithium-soap grease, free of resin and acid, not liable to crumble and with good rust-preventive characteristics. The grease should have a penetration number (NLGI class) between 2 and 3, corresponding to a worked penetration between 220 and 295 mm/10. Its drop point must not be below 175￿C. The bearing cavities must only be half-filled with grease.

If required, the bearings may be lubricated with greases of other soap bases. Since greases of differing soap bases must not be mixed, the bearings must be thoroughly cleaned beforehand. The re-lubrication intervals required must then be adjusted to the greases used.

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