TP40-80/2 Shaft Seals Manual

33
Types of shaft seals
Shaft seals
Grundfos type H
Grundfos type H seal is defined as an O-ring seal of the
cartridge type.
Description/features
• Thanks to the balanced seal design, this robust seal
is suitable for pressures up to 30 bar.
• Can be replaced without dismantling the pump part.
• Easy to replace during service.
• Risk of fretting (wear corrosion) in corrosive liquids.
Fretting occurs when an O-ring wears the protective
oxide film of a stainless steel shaft. As the seal is
designed as a cartridge seal with a sleeve on the
shaft, fretting damages the sleeve and not the shaft.
This enables replacement of the seal without having
to make an entire renovation of the pump.
• Risk of deposits around the O-ring as well as sei-
zure of the O-ring in liquids with a large content of
lime or sludge.
Fig. 45
Type H seal
Application profiles
The type H seal has the following application profiles:
• SiC/SiC
• SiC/carbon
• tungsten carbide/carbon
• tungsten carbide/tungsten carbide.
Type H for ø12, ø16 and ø22 mm shaft with SiC/SiC
(Q
1
G
/Q
1
G
) seal faces
• The seal is suitable for use in CR/CRI/CRN pumps.
• The strong seal carriers contribute considerably to
the cooling of the seal faces in case of dry running.
This makes the seal capable of withstanding several
minutes of dry running, despite the seal face mate-
rial combination.
• Suitable for lime- and sludge-containing liquids
where there is a risk of deposits and seizure.
There is no relation between the indication of suitability
and the pressure-temperature diagram, but together
they form the application profile.
Suitability
Pressure-temperature diagram
The pressure-temperature diagram is based on clean
water.
The figures in the following table refer to the pressure-
temperature diagram.
Fig. 46
Pressure-temperature diagrams
TM02 7100 2603
Suitable
Suitable under
certain
conditions
Not
suitable
Alkaline liquids
Acid liquids
Dry running
Solid particles in liquid
Precipitating/lime-
containing liquids
Anti-freeze liquids
Pos. Range
1 Optimum duty range
2
Risk of periodical noise in connection with start-up and
variations in pressure and temperature
3 Risk of periodical noise and reduced lifetime.
TM02 8448 0204
10 20 30 40 50 60 70 80 90 100 110 120 130 140 150
[˚C]
16 mm
30
25
20
15
10
5
0
0
[bar]
-40 -30 -20 -10
10 20 30 40 50 60 70 80 90 100 110 120 130 140 150
[˚C]
22 mm
0
0-40 -30 -20 -10
2
3
1
1
2
3
10 20 30 40 50 60 70 80 90 100 110 120 130 140 150
[˚C]
12 mm
30
25
20
15
10
5
0
0
[bar]
-40 -30 -20 -10
1
2
3
30
25
20
15
10
5
[bar]