Main design features
- DDH pumps, with a double suction 1st. stage impeller, balanced by means of back wear ring on the 2nd stage impeller.
- Suction and discharge nozzles, integrally cast with the casing, are normally arranged in top-top position, but side-top
or side-side nozzle arrangements are available.
- Ample balancing line from 2nd. stage to suction maintain stuffing box pressures within limits easily acceptable by any
type of balanced mechanical seals.
- Centerline casing mounting for high temperature stability.
- Stiff shaft design. Rotor operates below 1st critical speed.
- Deep stuffing boxes designed in accordance to API 682 Std., suitable to accept any type of mechanical or packing seals.
- Labyrinths and deflectors at either bearing housing to maximise protection against dirt.
- Three bearings arrangements available:
- Ball Radial / Ball Thrust
- Sleeve Radial / Ball Thrust
- Sleeve Radial / Tilting Pads Thrust (Kingsbury Type).
Technical data
- Capacities: up to 1800 m3/h (8000 gpm)
- Heads: up to 760 m (2500 feet)
- Temperatures: from -30°C (-20°F) to 455°C (850°F)
- Design working pressure: up to 210 barg (3000 Psig)
- Rotational speed: up to 4000 rpm
- Max hydrotest pressure: up to 305 barg (4500 Psig)
Design Variations
The following pump designs can be provided:
- For extremely low NPSH duties, a number of DDH pumps can be equipped with inducers.
- Steam jacketed casing for special applications.
- Replaceable stuffing box cooling or heating jackets.
- Double shaft extension.
- Cylindrical fit at coupling shaft end.
- Special bearing isolators at either bearing housing ends.
- Roller, "CARB" or hydrodynamic line bearing for high temperature application.
- Oil mist lubrication system (pure or purge).
- Forced feed lubrication system.
- Temperature and/or vibration detection and monitoring equipment.
Applications
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