Coupling Guard; Piping; Gap Between Flanges - GE OSMONICS TONKAFLO SS Series Installation, Operation And Maintenance Manual

3.6

Coupling Guard

Coupling guards are available for all Tonkaflo pumps. GE recommends a coupling
guard. Check your plant safety requirements.
3.7

Piping

The pump inlet housing has been designed for either upright or left or right horizontal
positioning. For left or right position, remove the 4 bolts holding the suction (inlet)
housing to the bearing frame. Rotate the suction housing 90° and replace the 4 bolts.
For left or right position, a pipe plug can be removed to vent off any air in the top of
the pump inlet housing should "venting" be required for pump priming and start-up for
your installation.
Suction (pump inlet) piping should be of ample size, installed in direct runs, and have
a minimum of bends to minimize pressure loss and to help ensure sufficient suction
pressure. When possible, keep the suction pipe short.
The suction (inlet) pipe size immediately ahead of the pump inlet should be sufficiently
sized so that the pressure available at the pump suction (inlet) exceeds the Net
Positive Suction Head (NPSH) required by the pump. Generally, the suction (inlet)
piping should be 4-inches (10.2 cm) for flows greater than 170 gpm (38.6 m
3-inches (7.6 cm) for 100 gpm - 170 gpm (22.7 - 38.6 m
60 gpm - 100 gpm (13.6 - 22.7 m
3
(13.6 m /h) or less (see frictional loss and pressure loss discussion below).
The recommended pipe size for most applications should result in frictional line loss
of 3 psig per 100 feet (0.21 barg per 30.5 m) or less for suction lines and 10 psig per
100 feet (0.69 bar per 30.5 m) or less for discharge lines. A larger pipe size will reduce
the frictional line loss.
The pump inlet piping should be designed to avoid areas where air may be trapped
and accumulated. Keep the suction pipe free of high points and thus air pockets,
which tend to disrupt pump priming and start-up. Suction pipe size changes just
ahead of the pump should be tapered. Reducers should be eccentric to avoid air
pockets.
Coupling
Size
6
7
8
9
Figure 3.3

Gap Between Flanges

3
/h), and 2-inches (5.1 cm) or greater for 60 gpm
9
G a p
inch mm
7/8 22.2
1 25.4
1-1/8 28.6
1-7/16 36.5
3
/h), 2-1/2 inches (6.4 cm) for
3
/h),