Pentax HP Manual Del Usuario página 44

2. TECHNICAL SPECIFICATIONS
2.1 • CONSTRUCTION
The multistage horizontal or vertical pumps are constructed from a suction cas-
ing, a discharge casing and stage casing, all mounted on a common drive shaft.
The radial impellers are cast with double curvature form and diffusers are posi-
tioned inside each stage casing (fig.11).
Stage sealing is achieved by O-rings, pressurized by a controlled axial load
applied by external tie rods.
For the horizontal pumps the cast feet on the baseframe are positioned under
the delivery casing and under the suction casing.
For vertical pumps, the baseframe is in the suction casing, in the lower part.
MAIN BEARINGS AND HYDRAULIC BALANCING
The driveshaft is supported by bearings lubricated by either oil grease,
mounted in the flanged supports, on the pump ends, in particular:
– 1 radial ball bearing and 2 angular ball bearing in the HP pumps
– 3 angular ball bearings and 1 roll bearing in the HPM pumps
– 2 angular ball bearing and a sliding sleeve in the HV pumps
– 2 angular ball bearing and 1 roll bearing in the HVM pumps
The axial thrust from the impellers is hydraulically balanced at each stage, additional hydraulic bal-
ance is achived with a pressure discharge bush in the delivery casing. Any remaining axial thrust is
absorbed by the angular main bearing or by the ball bearing.
SHAFT SEAL
The pumps are available with standard uncooled packed gland sealing for water tempera- tures
up to 105°C or, on request, with water cooled packed glands for temperatures between
105°C to 140°C (fig. 12).
The pumps can also be fitted with uncooled mechanical seals for special applications and fluid
temperatures up to 140°C (fig. 13).
The pump driveshaft is protected in the sealing area by a replaceable sleeve.
SUCTION AND DELIVERY PORT ORIENTATION
For HP, HPM, HPR pumps standard build: suction port on left hand side of pump when viewed
from end of drive shaft in standard position ie, at suction end of pump. Delivery port is
vertical. On special request, pumps can be supplied with the suction port either vertical or on
right hand side of pump.(fig.14)
HV, HVM pumps standard execution: opposite ports; special execution: different positioning.
STANDARD FLANGES
Suction flange for HP, HPM, HV, HVM series pumps, are machined to UNI2237
PN16. to UNI 2238 PN 25 for HPR pumps.
Delivery flange for HP, HPM, HV,HVM pumps UNI 2243 PN 64, to UNI 2244
PN 100 HPR pumps.
Flange adaptors machined to ANSI are available on request.
MATERIALS OF CONSTRUCTIONS
Pumps can be supplied with: suction and delivery casings, intermediate casings, impellers
and diffusers in cast iron, stainless steel or bronze. Driveshafts and sleeves in stainless
steel. For specific materials, please look it up in the technical catalogue.
ON REQUEST
ON REQUEST
9
Stage casing
Impellers
O-ring
Suction casing
Foots
Bearing
Fig.14
STANDARD
Discharge casing
Bracket
Bearing
Foots
Tie-Rod
Fig.11
Fig.12
Gland packing
Gland packing seal
Mecanical seal
Fig.13