KRAL K Series three-screw pump — a pump for fuel oil, lubricating oils and diesel fuel; models KF, KH, KV, KFT

KRAL - Three screw pump (K Series)

KRAL K-series fuel oil pump — a three-screw pump for heavy fuels, lubricants and diesel fuel. Manufacturer: KRAL, Austria, and describes the range as versatile: this is the widest range of sizes in the range, from 5 to 2,900 l/min at a pressure of up to 16 bar. The parts in this series are manufactured to tolerances for installation on vessels.

Why is the K series called versatile

There are two reasons. The first is— span: one series covers even a small area a circuit comprising several litres per minute, and a main pipe with a capacity of 2 900 l/min. No other KRAL series is like this It does not provide a range.

The second is the environment. Heavy fuels, lubricants and diesel fuel with a viscosity range of 2 to 10,000 mm²/s is sufficient for most applications fuel and lubricants management. Where higher pressure is required, take KRAL L Series up to 63 bar or KRAL C Series up to 100 bar; where the fluid is contaminated or not lubricates, — KRAL W Series.

On the principle of operation of a screw pair — how a screw pair works.

Technical characteristics KRAL K Series

Parameter	Value
Type	three-screw pump
Capacity	5–2,900 l/min (KFT model — 5–420 l/min)
Max. pressure at the discharge flange	16 bar
Viscosity	2–10,000 mm²/s
Housing material	high-strength EN-GJS-400 cast iron
Screws	nitrided steel
Models	KF, KH, KV, KFT

Size range according to the manufacturer’s website: 15–42, 55–118, 160–275, 370–450, 550–660, 851–1301, 1500–1700, 2200–2900. The designation corresponds to the flow rate in litres per minute at 1450 rpm.

The key data are taken from the manufacturer’s catalogue, edition 07/2007.

The seal determines temperature and inlet head

Gaskets	Max. temperature	Max. inlet pressure
Cuff-type, NBR	80 °C	1.5 bar
Cuff-type, FKM	150 °C	1.5 bar
Flat-ended, standard	150 °C	6 bar
Facing, made of hard SiC material	180 °C	10 bar
Magnetic clutch	250 °C	10 bar

Also available a balanced mechanical seal and end-to-end flushing — for circuits with an elevated backrest or a polluted environment.

The difference between a mechanical seal and a hard-wearing end cap — almost seven times the permissible inlet pressure. If the pump is situated beneath the tank, this is the primary selection criterion, rather than temperature.

Implementation of KF, KH, KV and KFT

KF — flanged pump
KH — a pump on legs
KV — a pump on a support
KFT — a pump with top flanges to DIN standards, flow rate 5–420 l/min

The hydraulics are the same; the choice depends on the layout: integration into the pipework, mounting on the frame or on the tank.

Certificates and ship permits

Classification societies: ABS, BV, CCS, DNV, GL, LRS, MRS, NK, RINA.
Explosion protection: ATEX, Group II, Category 2.

The manufacturer specifically states that the series is approved for installation on vessels. The exact set of documents will be confirmed upon order.

Current versions — on the manufacturer’s website KRAL.

Where K-series pumps are used

According to the manufacturer’s catalogue:

marine fuels and lubrication systems
mechanical engineering
torch technique, fuel supply to burners
plastics processing
tank farms and loading jetties

Thised.Applications: heavy fuels, lubricants, diesel fuel.

Selection and service provided by Steiner Ukraine

The versatility of the series K does not mean that Any standard size will do. The range starts from 5 up to 2,900 l/min simply means that the required the operating point in it you can almost always find it — but finding it It’s definitely needed, because the pump, chosen with a margin, performs worse than chosen. We We determine the flow rate, pressure, viscosity at operating temperature and inlet head, and use these to select the size, model and seal type. Next — service and spare parts. Steiner Ukraine has been operating in the industrial equipment market since 2006.