Crank Mechanism
PTO/PQO/PSO Range
Reciprocating pumps to API 674
The PTO-PQO-PSO series complies with API 674 and ASME standards and are specifically designed and manufactured for process applications where continuous heavy duties up to 2500 kw are involved.
The series includes two pump sizes, 160 and 190. For each size, triplex and quintuplex versions are available together with a septuplex model for the 190 size.
Quintuplex or septuplex pumps, compared with a triplex pump of equivalent performances, have reduced static and dynamic loads and lower pressure pulsations which simplifies piping design. This results in higher reliability, less maintenance and smoother operation of the pump.
The PTO/PQO/PSO series covers the highest performance range of reciprocating pumps and the flexible design allows the installation of both plunger and piston type liquid ends.
The main features of the crank mechanism are:
- Continuous shaft support with individual sleeve bearings for each plunger and hence reduced stresses making them intrinsically safe against shaft failure.
- Connection of the plunger to the crankmechanism through a spherical joint with subsequent limited loads on the sealing area.
The smallest pump of the series, model PTO 160, is also available with traditional shaft support with two roller bearings at the shaft ends, together with all the other characteristics of the series.
Liquid end
In order to meet various operating conditions and fluid characteristics, the hydraulic end incorporates different configurations of manifold, valve assembly and sealing systems and a variety of materials to suit each specific application.
The standard hydraulic end arrangement is suitable for a wide range of operating conditions, hazardous fluids and/or containing suspended solids.
Other hydraulic solutions are available for high viscosity fluids and pumping conditions at high or low temperature.
Specific liquid end designs are also available for handling slurries with a significant content of solid particles (in terms of size and weight percentage).
Valves and sealings
Various types of valves are available to meet available NPSH conditions and to suit the characteristics of different fluids, including solids content.
Sealing systems are designed according to the physical characteristics of the fluid and the risk of contact with the atmosphere.
