Special Operating Conditions; Chargeable Liquids; Identification; Check Of The Direction Of Rotation - Richter MNK-B Series Installation And Operating Manual

Sealless chemical magnetic drive pump

Hide thumbs

Table Of Contents

Table of Contents

Enlarged version

Series MNK-B,

size 25-25-100

2.6.2 Special operating conditions

The plain bearings are cooled and lubricated

by a flushing flow.

Owing to properties of the medium (e.g. sticking due

to inadmissible solids entrainment, clogging, gas

entrainment etc.) the cooling flow can be interrupted

and, as a result, an inadmissible temperature rise may

occur. Provide appropriate monitoring facilities. See

Section 5.6.

For safe pump operation, we recommend a flow rate

of 0.3 to 1.1 Q

. If the pump is operated outside this

opt

range, it must be ensured that the max. admissible

flow rate according to the pump characteristic curve is

not exceeded and that the max. admissible operating

temperature according to Section 2.6.7 is observed.

If the flow rate is too high, the differential pressure

upstream and downstream of the plain bearings could

fall so much that a lack of lubrication or dry-running

may occur.

If the flow rate is too low, the medium may heat up so

much owing to the fluid friction that the max.

admissible surface temperature of the relevant

temperature class is exceeded.

Overloading, overheating or non-observance of the

design data may lead to the decoupling of the

magnetic drive. As a result, eddy currents are induced

on the magnetic drive and the metallic back plate and

an inadmissible rise in temperature may occur.

The situation is to be remedied by providing

appropriate monitoring facilities. See Section 5.6.

The plant NPSH value (NPSHA) should be minimum

0.5 m higher than the NPSH value of the pump

(NPSHR) to prevent a lack of lubrication or dry-

running of the plain bearings.

2.6.3 Chargeable liquids

For operation with chargeable liquids with a

conductivity < 10

for flushing during evacuation if the lining of

the pump is non-conductive. See Section 6.3.

2.6.4 Identification

The identification on the pump relates to the

pump section. A separate declaration of

conformity must be provided for the shaft

coupling and motor and for other attachments as well

as corresponding identification.

Example of the identification of the pump section:

II2GD IIC TX X.

For assembling the pump with components which are

not explosion-protected (e.g. motor, shaft coupling), it

is recommended to mask or remove the "potentially

explosive" identification from the pump component

and, if necessary, from other accessories.

9230-056-en

Revision 14

TM 9542

Edition 06/2016

-8

S/m inert gas must be used

In this case the declaration of conformity applies

without ATEX identification.

At surface temperatures which depend primarily on

operating conditions, DIN EN 13463-1 Chapter 9.3

allows no temperature class or temperature to be

indicated.

The temperature class must be determined by the

operator

accordance

"Temperature Limits".

2.6.5 Check of the direction of rotation

If there is also a risk of explosion during the

installation phase, the check of the direction of

rotation must under no circumstances be conducted

by briefly switching on the unfilled pump in order to

prevent an inadmissible rise in temperature at the

plain bearings.

We recommend you to only perform a check

of the direction of rotation with filled pump and

with a rotating field instrument. See also

Section 6.1.2.

2.6.6 Mode of operation of the pump

The pump may only be started with the suction side

shut-off element fully opened and the discharge side

shut-off element slightly opened. Start-up against a

closed check valve is also possible. The discharge

side shut-off element is to be regulated to the

operating design point directly after run-up.