Swing Piston Pumps NPK 09
Servicing
7
5.1. Changing the piston seal
Spare part*
Quantity
Piston seal
1 (twin head pumps: 2)
Countersunk flat head screw (
14
)
2 (twin head pumps: 2)
Tab. 2
* According to Spare parts list, section 8
Tools/Material
Philips screwdriver no. 2
Screwdriver (blade width 5,5 mm)
Phillips screwdriver no. 1
Felt-tip pen
Tab. 3
In the case of twin head pumps both piston seals should always be
changed at the same time.
Dismantling
1. In the case of twin head models the connecting pipework
between the heads must first be removed.
2. Make a mark (
M
) on the ribbed head (
3
), intermediate plate (
2
),
and housing (
1
) with a felt-tip pen (see
M
in figures 3 and 4).
This helps avoid incorrect assembly later.
3. Unscrew the 4 screws (
4
) and take off the ribbed head (
3
).
4. Remove gasket (
6
), valve plate (
7
), intermediate plate (
2
) and
valve plate (
8
) from housing (
1
).
5. Only for the pump model NPK09 DC: Take off the cover (
18
)
after removing the 4 screws securing it.
For this pump type applies: Where reference is made to turning
or holding the cooling fan, the necessary operations must be
carried out by turning or holding the counter-weight (
17
).
6. Turn the fan to bring the retainer plate (
11
) to top dead center.
7. Pull the cylinder (
10
) upwards to remove it.
8. Hold the fan, loosen the retainer plate screw (
14
) and remove
screw, retainer plate, support (
12
) and washer(s) (
16
).
9. Remove the piston seal (
13
) from the retainer plate.
10. Check that all parts are free from dirt and clean them if
necessary (see section
6.Cleaning
).
11. Check the valve plates for damage (tongues bent, corrosion); if
necessary use new ones when reassembling.
Assembly
1. Hold the connecting rod (
16
) vertical, and replace the cylinder
(
10
) on the pump housing (
1
).
Parts required
Tools required
