HDX USER INSTRUCTIONS ENGLISH 85392696 - 01/11
Page 13 of 60
3 PUMP DESCRIPTION
3.1 Configurations
The HDX pumps are single stage, double suction
impeller, double volute radially split casing, centreline
mounted, with top nozzles heavy duty process
pumps.
On request, versions with side/side nozzles and high
pressure casing can be offered.
The HDX pumps provide both outstanding
performance and the highest reliability level as
required in the most arduous services of the process
industry where corrosive and volatile liquids are
pumped at high temperatures and pressures.
The different sizes available, combined with the
choice of impellers, ensure optimum efficiency
throughout the range.
Various options of construction materials and bearing
types are available.
3.2 Nomenclature
The pump size will be engraved on the nameplate
typically as below:
6-HDX-17-A
Nominal discharge branch size
Pump type
Nominal full size impeller diameter
Casing pattern type
The typical nomenclature above is the general guide
to the HDX description. Identify the actual pump size
and serial number from the pump nameplate. Check
that this agrees with the applicable certification
provided.
3.3 Design of major parts
3.3.1 Pump casing
The casing is radially split, dual volute, heavy walled,
centerline supported to achieve the safest and most
simple sealing and centerline supported to maintain
alignment at high temperatures.
Wall thickness and casing shape are chosen for the
maximum strength against stresses resulting from
combined high working pressure and high allowable
external loads on flanges.
The double volute casing minimizes the radial thrust
on the pump rotor and gives longer life to the seals,
bearings and wear rings.
3.3.2 Impeller
The standard double suction closed type impeller is
mounted with an interference fit and keyed to the
shaft, positively secured against axial movements by
a step in the shaft and a threaded shaft nut.
Impellers are designed to handle hot liquids close to
their boiling points. The symmetric pressure
distribution acting on impeller shrouds ensures
complete axial balance of the rotor.
3.3.3 Wearing Rings
The casing and the impeller are fitted with
replaceable wear rings of hardened material. The
rings are held in place by a press fit with locking pins
on the casing and with threaded dowels on the
impeller.
3.3.4 Rotors
Rotors are of the stiff shaft design.
Shafts are of ample diameter, combined with the
minimum bearing span to minimize shaft deflectors
especially when the pump is operating at off peak
conditions.
Shafts are designed to meet API 610 10
P
th
P
Edition
deflection and vibration requirements. Fully
assembled rotors are dynamically balanced can
accommodate a wide variety of single or dual seal
arrangements as standard.
3.3.5 Casing Covers
Two covers, one full size at the outboard pump end
which permits rotor removal and one reduced size
cover at inboard end provide circular type joints and
easy pump sealing with confined gaskets.
The metal to metal fit with confined controlled
compression gasket insures proper alignment
between casing and cover.
3.3.6 Bearing Housings
HDX pumps are fitted as standard with antifriction
bearings. The radial bearing is a deep groove type,
while the thrust bearings are dual single row angular
contact type.
Lubrication is provided by an oil slinger in conjunction
with a TRICO constant level oiler, both provided as
standard. In case of particularly severe operating
conditions sleeve line with antifriction or tilting pad
thrust bearing are available with self-contained or
external lube system.
Special bearing isolators (INPROSEAL or equivalent)
are available on request. Bearing housings can also
be adapted for optional oil mist or purge mist
lubrication systems.
