Efficient & Reliable Screw Pumps.

Maximum flexibility even under changing operating conditions. Pulsation free operation for high and low viscosity liquids.

KRAL Screw Pumps.
Pumping liquids is a demanding task.

When selecting and dimensioning a screw pump, the pumped liquid, the operating conditions, the installation site as well as the standards, guidelines and directives have to be taken into consideration. A wealth of knowledge is required in order to avoid errors.

KRAL screw pumps have existed since 1950. The acquired experience is passed on from generation to generation and extended continuously. Thus ensuring employees with excellent knowledge and further training. Our customers profit from our advisory skills.

Good control capabilities.
The delivery rate of a screw pump depends strongly on the speed. If the delivery rate has to be varied, a controller has to change the rotational speed. The complexity of the controller design depends on the delivery rate characteristics of the screw pump. In contrast to many other functional principles, KRAL screw pumps have linear delivery rate characteristics. Therefore they can be controlled simply and inexpensively by means of a frequency converter.

Low-pulsation transporting.
Pressure pulsations of the liquid can damage the screw pump, the system and the pumped liquid. The strength of the pulsation depends on the functional principle of the pump. Piston and gear pumps cause considerably more pulsations than a screw pump. The KRAL screw pump feed method conserves product. The pumped liquid is not pressed, there are no pressure pulses that can damage the piping and other components or trigger vibrations. In addition, KRAL screw pumps are very quiet.

High power density.
Space for setting up or installing screw pumps is expensive or often short. KRAL screw pumps offer high delivery rates at small space requirements in comparison to other pump types.

Efficiency.
In comparison to other types of pumps, KRAL screw pumps offer a high delivery rate but don’t take up a lot of space. KRAL pumps are low in pulsation and run quiet.

Technical advantages.

Optimized flange construction.
Flanges are constructed according to ISO 3019. This means that KRAL pumps can be connected to common pump mounts. The type of construction used minimizes the size for an optional magnetic coupling.

Wear reducing surface treatment.
A special heat treatment of the pump housing minimizes friction and wear.

Optimal cooling and lubrication.
The application specific design of the balancing cylinder ensures proper cooling and lubrication of the sealing surfaces of the mechanical seals.

Self-purging.
Venting between the positive pressure side and the negative pressure side directly depends on the mechanical seal. In this way, it’s ensured that the air buffer through the medium in the vent line can be eliminated, even for vertical installation

High quality bearings.
KRAL pumps are equipped with lifetime lubricated and sealed bearings. This increases the lifespan and reduces maintenance costs.

Durable o-rings.
High quality o-rings are chemically stable and can withstand high temperatures of up to 180 °C.

Optional seals.
Standard seals are available with various qualities. Options include magnetic couplings, radial seal rings and mechanical seals with fluid (quench type).

Standard seals.
Depending on the requirements of the application, various types of mechanical sealare available that conform to DIN EN 12756.

Top quality SiC development.
The highly developed SiC quality of our mechanical seals contain graphite as a dry lubricant. This reduces damaging friction during dry operation.

No accumulation of residue.
Leakage from the mechanical seals is directly diverted from the stationary seal ring via a vent hold. There is no unnoticed accumulation of residue that might damage the bearings.

The Right Pump Series for Your Needs.

Delivery rate	Pressure	Temperature	Series	Position in KRAL product line
5 to 2,900 l/min 0.3 to 174 m³/h	16 bar	-20 to 180 ℃	K	This economical, most sold KRAL pump can be used at pressures up to 16 bar.
5 to 200 l/min 0.3 to 12 m³/h	63 bar	-20 to 180 ℃	L	The mid-pressure pump from KRAL. Robust, low wear and easy to maintain.
5 to 3,550 l/min 0.3 to 213 m³/h	100 bar	-20 to 180 ℃	C	The all-rounder – when needs exceed the standard K or L series pumps.
15 to 290 l/min 0.9 to 17.4 m³/h	120 bar	-20 to 180 ℃	W	The pump for special applications, for example contaminated, abrasive or low viscosity media.
1,300 to 11,000 l/min 80 to 660 m³/h	25 bar	-40 to 300 ℃	Z	Suitable even for aggressive and contaminated media.
5 to 3,550 l/min 0.3 to 213 m³/h	100 bar	-20 to 300 ℃	Magnetic coupling	KRAL magnetic couplings are maintenance free, hermetically sealed and can be used at temperatures up to 300 °C.
5 to 280 l/min 0.3 to 16.8 m³/h	40 bar	-20 to 180 ℃	Compact Station EK, EL	This is a commercial/economical oil burner pump with additional functions.
5 to 280 l/min 0.3 to 16.8 m³/h	40 bar	-20 to 180 ℃	Compact Station DKC, DLC, DS/L	Dual pumps are ideal when redundancy and greater safety are needed.
5 to 3,550 l/min 0.3 to 213 m³/h	100 bar	-20 to 180 ℃	Single Station	Available in a standard design, or can be set up according to specific customer needs.
5 to 3,550 l/min 0.3 to 213 m³/h	100 bar	-20 to 180 ℃	Double Station	Available in a standard design, or can be set up according to specific customer needs.