B, BC, MBM, MBMC
ATEX gear pumps
B, BC, MBM, MBMC pumps are volumetric gear pumps suitable for transferring lubricant viscous liquids without any suspended solids or abrasive substances. They are self-priming pumps used for a wide range of liquids with a viscosity from 1 to 20000 cSt. The speed of rotation is chosen according to the viscosity of the liquid. Flowrate range is from 5 to 800 L/min.
The standard construction consists of pump housing and cover in cast iron, shafts and gears in carbon steel, gaskets in Flexoid, sleeve bushings in Steel-Bronze-PTFE and a mechanical seal in ceramic-graphite-Viton. These pumps are supplied with a pressure relief valve in brass.
Nozzles in inlet and outlet are of the same diameter and positioned on the same axis.
A short and straight alignment of the flow channels provides for a good suction capability and a quiet running. The helical gears result in extremely low noise levels and reduced pressure pulsation.
B, BC pumps are tipically installed on a skid and driven by an electric motor by means of an flexible coupling (MBM, MBMC series). The sizes from 10 to 400 are also available with a heating chamber integrated in the pump housing (BC, MBMC series).
The main options available are:
• Counter-clockwise rotation
• Options on relief valve
• Special seals according to liquids and temperatures
• On skid with electric motor
• Constructions for corrosive liquids and aggressive environments
• Heating solutions
• Accessories
Nominal flow rates
This table shows the possible flow rates for non-pressurized speed. The selected speeds are the most common speeds pumping (Δp=0) and a 46 cSt fluid. at rated power of industrial electric motors at 50 and 60Hz. The flow rate of gear pumps is virtually proportional to their
B, BC – SENSE OF ROTATION AND FLOW DIRECTION
The standard version of B and BC pumps can operate only in one direction of rotation: clockwise watching the pump shaft-end.
The direction of the fluid flow is shown by an arrow placed nearby the piping connections.
A proper mounting will keep the nameplate on the top side. The flow direction will be from the left side to the right-side watching the pump shaft-end and the pressure side (delivery) will be at the right side.
On request a counterclockwise version can be supplied.
MBM, MBMC – SENSE OF ROTATION AND FLOW DIRECTION
The standard version of MBM and MBMC pumps can operate only in one sense of rotation: clockwise watching the electric motor fan.
The sense of rotation of the motor, when properly connected to the mains, is shown by an arrow placed on
the fan cover. Watching the electric motor fan, the flow direction will be from the left side to the right side and the pressure side (delivery) will be at the right side.
On request a counterclockwise version can be supplied.
PRESSURE RELIEF VALVE
B, BC, MBM, MBMC pumps are supplied with a brass pressure relief valve as a standard. It works only on outlet, in one direction.
It may be used as a safety valve only for short-term operations. When a partial discharge flow has to be drained over a prolonged period of time, a separate by-pass valve with return to the suction tank has to be installed into the piping.
The pressure relief valve is designed as a spring-preloaded
piston valve. It is integrated into the pump’s end cover. The spring pretension and the relative opening pressure can be adjusted by means of a screw. Different springs are also available to reach the desired adjustment range.
The pressure relief valve is available on request in stainless steel contruction.
As an option the pumps can be supplied without relief valve.
SHAFT-END SEALS
The standard version is fitted with mechanical seal in ceramic-graphite-FPM. A number of different seals materials can be supplied for different liquids and operating temperatures.
On request:
• Radial lip-type seal in FPM (Viton), NBR or PTFE (Teflon) • Packing seal in Acrylic yarn-PTFE
• Seal for high temperatures up to 200°C
• Reversible mechanical seal
• Dual mechanical seal; available also with flushing
system or quench
VERSION FOR AGGRESSIVE LIQUIDS AND ENVIRONMENTS
B, BC, MBM, MBMC pumps can be supplied in a corrosion and acid-resistant construction.
Stainless-steel version
Pump housing, cover, shaft and gears in stainless steel and sleeve bushings in AISI 316-Bronze-PTFE.
Bronze version
Pump housing and cover in bronze, shaft and gears in stainless
steel and sleeve bushings in AISI 316-Bronze-PTFE.
Seals and gaskets materials are choosen according to the liquid pumped.
Many combinations suitable for corrosive liquids and aggressive environment can be supplied as follows:
• Gears in bronze
• Sleeve bushings in PTFE or Tecapeek
VERSION WITH HEATING CHAMBER (BC, MBMC)
BC pumps, available from size 10 to 400, have got a heating chamber integrated in the pump housing.
BC pumps are useful when the pumped liquid (such as bitumen or wax) needs to be heated in order to prevent the liquid from hardening. The heating chamber works with a circulation of diatermic oil, hot water or saturated vapor.
A different heating solution, as an alternative to the heating chamber, is to provide holes for glow-plug or electric resistances (not included).
MBMC serie consists in a BC pump mounted on a skid and coupled to electric motor by means flexible coupling.
