{"id":1588568,"date":"2025-06-12T12:12:54","date_gmt":"2025-06-12T09:12:54","guid":{"rendered":"https:\/\/steiner.com.ua\/?post_type=product&p=1588568"},"modified":"2026-08-31T16:25:16","modified_gmt":"2026-08-31T13:25:16","slug":"kral-trygvyntovyj-nasos-f-series","status":"publish","type":"product","link":"https:\/\/steiner.com.ua\/en\/catalog\/kral-trygvyntovyj-nasos-f-series\/","title":{"rendered":"KRAL - Three screw pump (F Series)"},"content":{"rendered":"

The KRAL F-series biofuel pump is a triple-screw pump designed for alternative fuels: biodiesel, methanol, ammonia, ethanol, HVO and FAME. The manufacturer is KRAL, Austria, and it positions the series specifically as a pump for the fuels of the future. The housing and all parts in contact with the fluid are made of stainless steel, whilst the drive consists of a sealed magnetic coupling as standard.<\/p>\n

For which fuels is the F series designed?<\/h2>\n

The manufacturer specifically lists the following media: biofuels, methanol, ammonia, ethanol, HVO and FAME. It is specifically noted that the pump is suitable for fuels with an acid number exceeding 0.5 mg KOH\/g \u2014 it is precisely this acidity that makes alternative fuels problematic for conventional cast-iron pumps.<\/p>\n

The second challenge is viscosity. Methanol and ammonia have virtually no lubricating properties, and the F series is designed to operate at 0.2 mm\u00b2\/s or higher, which is lower than that of diesel fuel.<\/p>\n

Why are stainless steel and magnetic couplings the standard here?<\/h2>\n

Acidic and corrosive fuels corrode cast iron, which is why the housing, screws and the entire flow path are made of stainless steel; the screws also have increased surface hardness and special coatings.<\/p>\n

Methanol and ammonia are toxic and volatile, so a leak is unacceptable under any circumstances. There is no mechanical seal here \u2014 the torque is transmitted via a sealed magnetic clutch<\/a>, and in the F series, this is not an option but comes as standard.<\/p>\n

How a screw pair works \u2014 how a screw pair works<\/a>.<\/p>\n

Technical Specifications of the KRAL F Series<\/h2>\n
\n\n\n\n\n\n\n\n\n
Size<\/th>\nFlow rate (2,900 min\u207b\u00b9, 40 bar, 1 mm\u00b2\/s)<\/th>\n<\/tr>\n<\/thead>\n
15-20<\/td>\nup to 25 l\/min<\/td>\n<\/tr>\n
32-42<\/td>\nup to 60 l\/min<\/td>\n<\/tr>\n
55-74-85<\/td>\nup to 120 l\/min<\/td>\n<\/tr>\n
105-118<\/td>\nup to 180 litres per minute<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<\/div>\n
\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n
Parameter<\/th>\nValue<\/th>\n<\/tr>\n<\/thead>\n
Type<\/td>\nthree-screw pump, hermetically sealed design<\/td>\n<\/tr>\n
Max. differential pressure<\/td>\n120 bar<\/td>\n<\/tr>\n
Max. supply pressure<\/td>\n16 bar<\/td>\n<\/tr>\n
Max. temperature<\/td>\n80 \u00b0C<\/td>\n<\/tr>\n
Viscosity<\/td>\nfrom 0.2 mm\u00b2\/s<\/td>\n<\/tr>\n
Max. revs<\/td>\n4,000 min\u207b\u00b9<\/td>\n<\/tr>\n
Material of the housing and wetted parts<\/td>\nstainless steel (as standard)<\/td>\n<\/tr>\n
Screws<\/td>\nstainless steel, increased surface hardness, special coatings<\/td>\n<\/tr>\n
Drive<\/td>\nmagnetic clutch (as standard)<\/td>\n<\/tr>\n
Explosion protection<\/td>\nATEX, Zones 1 and 2<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<\/div>\n

The differential pressure depends on the fuel<\/h2>\n

The overall limit for the series is 120 bar, but the manufacturer specifies individual values for specific media:<\/p>\n

\n\n\n\n\n\n\n
Environment<\/th>\nDifferential pressure<\/th>\n<\/tr>\n<\/thead>\n
Light fuel oil (LFO), biofuels<\/td>\nup to 80 bar<\/td>\n<\/tr>\n
Methanol, ammonia<\/td>\nup to 30 bar<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<\/div>\n

This is not a safety margin, but an operational limit \u2014 it must be factored into the circuit calculations as early as the design stage.<\/p>\n

Implementation<\/h2>\n

The manufacturer offers three versions: a flanged pump with an axial inlet, a flanged pump with a radial inlet, and a vertical pump mounted on a stand. The choice depends on the installation configuration: the vertical version is used for mounting on a tank, whilst the flanged versions are used for integration into a pipeline.<\/p>\n

A full list of models is available on the manufacturer\u2019s website KRAL<\/a>.<\/p>\n

Where are F-series pumps used?<\/h2>\n