Product Description
20
TT Twin-Screw Pump -
Installation, Operation & Maintenance Manual
Product Description
General description
Product description
The TT Series Twin-Screw pump is a positive displacement pump capable of handling
viscosities from 0.2cSt up to >100.000cSt. Due to the fully non-contacting rotor design
(following API676 MPP requirements) this pump is perfectly suitable to handle all types of
fluids, viscosities and fluid mixtures. High gas contents as well as temporary dry run during
self-priming and resting operations can be pumped. This series offers higher flow capability
and better NPSH requirements than similarly sized pumps for these applications. With
discharge pressure limited to 20 barg, this high capacity pump’s narrower root diameter
increases the displacement, resulting in greater flow at the same pressure. The pump is made
up of two sets of opposed screws. Each set of screws conveys liquid toward the center of the
pump where the discharge port is located. Since hydraulic forces are opposite and equal, the
rotor is hydraulically balanced in the axial direction.
Casing
– The casing is foot mounted with side -suction and top discharge nozzle. TT series
are equipped with DIN/ASME flanges. DIN Suction flanges class PN250, 300, 350, 400, 450
and 600. DIN Discharge flanges class PN200, 250, 300, 350,400 and 550. ASME flanges class
150 and 300 are also available. The solid cast body has thick cross sections for rigidity. Body
passages are designed to eliminate dead spaces to prevent liquid stagnation. Direct flow path
from suction opening to entrance of pumping screws has hydraulically wide open to improve
efficiency and NPSH behavior. The result is more uniform velocity changes for lower entrance
friction losses and consequently higher suction lift capabilities.
Screw/Shaft
– Engineered rotors are built up from separate shafts and screw to utilize the best
possible material combination for the process and the most efficient fabrication methods for
shaft and screw fabrication. Shafts and screws are manufactured separately and assembled
together into one robust mechanical unit allowing for maximum rigidity and stiffness. This
minimizes shaft deflection, an important consideration in high-pressure service. Screw block
root diameter are reduced for greater displacement. Basically, the pump is equipped with
engineered screw block/split screws and on request integral screw shaft can also be
manufactured.
Seal Chamber
– The seal chambers are under suction pressure only. They are designed to
accommodate standard single in either a component or cartridge configuration. Seal chamber
tapping’s can be configured to support most API 682 seal plans. On applications where,
