A Rubber Rotary Lobe Pump is considered a viable alternative to Peristaltic and Progressing Cavity Pumps due to their in-line design which enables easy and simple integration into pipework systems.

The MG Rotary Lobe Pumps have a reversible design which means they are ideal for tank emptying and refilling applications which removes the requirement for line stripping or a secondary pump for many users. The pumps also feature a relatively small pump head and the versatility available in drive configurations allows the Industrial Lobe Pump to be easily integrated onto mobile systems such as tankers and tractors. You can find more information about the drive configurations in the relevant tab.

Features and Benefits of the Rotary Lobe Pump

The main features and benefits of the MG Industrial Rubber Rotary Lobe Pumps can be summarised as follows:

Near pulseless, reversible flow
Gentle product handling & low shear effect on fluid
Self-Priming to 5m
Replaceable Wear Plates at front and back of the pump housing in Wear Resistant Steel (400 HB)
Hardened bushes as standard increase wear resistance & reliability in arduous and abrasive applications
Bean-shaped lobes facilitate easier and smoother passage of solids
Short Dry Running Capability thanks to Grease Lubricated Seals
Seal Leakage Checking System enables quick and easy inspection
Swan Neck Suction & Discharge Manifolds aide in Priming & and can be fitted with Pressure Gauges for a quick inspection of pump & system conditions. Drain & Vent Ports are also fitted as standard.
Quick & Easy Lobe Maintenance & Inspection thanks to Front Pull-Out Design – Pump can be left in the pipework, Seals & Transmission system are left untouched.
ATEX Rated Models are MG07, 14, 20, 27 & 40

Industrial Rotary Lobe Pump Applications

These Industrial Rotary Lobe Pump has been designed for the transfer of viscous, fibrous, abrasive and solids laden products within the following industries:

Industrial: Lime milk, molasses, resins, paper & pulp, ceramics, machining of glass and marble
Water Treatment: Sewage, dewatered sludge, sludge clarifier, activated sludge, digested sludge, lime milk, raw sludge, polymers & slurries
Petro-Chemical: Crude oil, solvents, heavy oils, waste oils
Anaerobic Digestion: Digestate, Feedstock Supply, Waste Waters & Slurries
Marine: Waste Waters & Dirty Oil Transfers

Rotary Lobe Pump Options according to Application

		Lobes
		NBR	EPDM	Viton	SBR	Polyurethane
Generally Resistant to most		Hydrocarbons, Fats, Oils	Vegetable & Animal Fats, Oils, Ozone, Aromatics, Aliphatic, Hydraulic Fluids, Chemicals	Elongated Hydrocarbons, Acids	Acids, Water & Chemicals Good abrasion Resistance	Mineral Oils, Aromatic & Aliphatic Hydrocarbons
Generally Attacked by		Ozone, Ketones, Esters, Aldehydes, Nitro & Chlorinated Hydrocarbons	Mineral Oils, Solvents, Aromatic Hydrocarbons	Ketones, Low Molecular Weight Esters, Nitro Containing Compounds	Ozone, Oils, Fats, Strong Acids & Hydrocarbons	Acids, Phenols, Toluene, Aldehydes & Ketones, Chlorinated Hydrocarbons
Resistance to	Oils	Very good	Poor	Excellent	No	Very good
	Fuels	Good	Poor	Excellent	No	Very good
	Ketones	Fair	Excellent	Poor	Fair	Poor
	Hydrocarbons	Good	Poor	Excellent	No	Poor

Tapflo UK also offer a Sanitary Lobe Pump from Pomac Pumps for hygienic applications.

Rotary Lobe Design

These Industrial Rotary Lobe Pumps are classified as Rotary Positive Displacement Pumps, this means the capacity remains independent from system pressure which means that they can deliver the same flow rate across their rated pressure. This ensures that the pumps are suited to mobile applications where discharge conditions are constantly changing or for fixed-in-place applications where process fluid viscosities and densities vary.

Pump bodies are constructed from GG 30 continuously cast spheroidal graphite Iron with wear plates in wear-resistant steel & triple seal design as standard.

Lobes can be supplied in several different elastomer coatings including NBR, SBR, XNBR, EPDM and FPM. Lobe replacement is facilitated by a front pull-out design.

Different drive options are available to suit a wide variety of site-specific requirements such as ATEX rated motor, hydraulic drives for truck mounting and diesel/petrol drives for portable systems.

Particular care has been taken in the design of these units to improve pump life and limit maintenance intervals in arduous and challenging applications. Each pump model has been through stringent and severe laboratory testing and field tests before being launched. Each pump is then individually tested before delivery.

Rotary Lobe Pump Construction

Housing	GG30 Cast Iron
Lobes	Cast Iron Coated in NBR, SBR, XNBR, EPDM and FPM
Shoulders / Wear Plates	Wear Resistant Steel (400 HB)
Shaft Seals	Double Radial Seals, Grease Lubricated & sliding on Hardened Bushes. Standard Mech Seals or Reinforced Seals (prepared to withstand higher operating pressures; equipped with a flushing system) on request
Manifolds	Galvanised Steel

Rotary Lobe Pump Drive Options

The MG Industrial Rotary Lobe Pumps are available as three different drive types: electrically, hydraulically and diesel driven.

Electrically Driven Lobe Pump

	Model
Detail	MG 7	MG 14	MG 20	MG 27
A	1500	1500	1500	1500
B	740	740	740	740
C	780	820	820	850
Weight, Kg	270	310	345	410
Flow Rate, l/min @ 460 rpm (3 Bar)	550	1100	1600	2000
Required Power, kW	5	10	15	17
Motor Power, kW	5.5	11	18.5	18.5
Protection Class	IP 55	IP 55	IP 55	IP 55
Voltage / Frequency	380 / 50	380 / 50	380 / 50	380 / 50

Hydraulically Driven Lobe Pump

	Model
Detail	MG 7	MG 14	MG 20	MG 27
A	645	710	775	865
B	270	270	270	270
C	500	500	500	500
Weight, Kg	132	142	160	187
Displacement, cm³/rev	34	44	61	72
Oil Pressure, Bar	120	140	140	140
Speed, rpm	2050	2050	2050	2050
Motor Connections	¾”	1”	1¼”	1¼”
Flow Rate, l/min @ 540 rpm (5 Bar)	650	1300	1800	2500

Diesel Driven Lobe Pump

	Model
Detail	MG 7	MG 14	MG 20	MG 27
A	1430	1550	1700	1700
B	750	750	845	845
C	930	930	1960**	1960**
Weight, Kg	390	430	660	700
No. of Cylinders	2	2	2	2
Power, kW	14	18	23	23
Displacement, cm³	1120	1332	2078	2078
Max Discharge Pressure	5*	5*	4.5*	5*
Flow Rate, l/min @ 520 rpm	650	1300	1800	2400

How does a Rotary Lobe Pump work?

2 synchronised lobes revolve within the pump housing. The lobes do not come into contact with one another, this is prevented by timing gears located within the gearbox. As the lobes rotate, they create an expanding cavity at the pump suction which draws the fluid into the pump. The fluid is trapped by the lobes in pockets as they rotate which is then conveyed around the outside of the lobes, passing any solids with it along the way, and discharging out of the pump casing.

The pump shaft support is facilitated by bearings located outside of the fluid in the gearbox, limiting the discharge pressure to 5 bar.

Capacity is directly related to the speed at which the pump is operated at and the flow is reversible by simply changing the direction of rotation of the drive.

Industrial Rotary Lobe Pump Performance Curves

MGIndustrial Rubber Lobe PumpViscosity Changes vs Suction Pressure, MG 7, 14, 20, 27 & 40:

Changes in viscosity can have a direct impact on the suction pressure to the pump. As temperatures drop the fluids viscosity will increase and therefore result in increases pressure drops on the suction pipework and over pressure in the discharge line. To prevent anomalies during operation and risk of cavitation, it is recommended to maintain an adequate suction pressure. Before start-up it is always recommended to ensure that the system’s NPSHa is higher than the pump’s NPSHr value. For reference, below is a chart detailing the NPSHr valves of the models MG 7, 14, 20, 27 & 40.