FELUWA MULTISAFE® double hose-diaphragm pumps
for abrasive, aggressive and toxic media

MULTISAFE® double Hose-diaphragm pumps

Efficient. Reliable. Environmentally friendly.

The unique, patented MULTISAFE® technology with the hermetically sealed redundant double hose-diaphragms ensures double safety for transportation of critical and environmentally hazardous fluids.

Two hose-diaphragms, arranged one inside the other, are fixed in the pump head. These hose-diaphragms enclose the medium ensuring double separation of the hydraulic drive end.

Pressure:up to 350 bar
Flow rates:up to 1,350 m³/h
Driving power:up to 5,000 kW


High operating safety: The conveyed fluid is not in contact with the pump casing.
Should one of the hose-diaphragms leak, the second one ensures that pump operation can still be continued until the system allows for shutdown and repair.

Unique diagnostic system: Permanent condition monitoring of essential items such as check valves and hose-diaphragm.

Innovative pump design: Absolutely safe against excess-pressure, vacuum and unfavourable suction conditions.

FELUWA TopEntry Valve Performance Monitoring System (FVPMS) Hose-Diaphragm Guard (HDG) TempGuard (TG) Double Safety! Pump Condition Guard (PCG)

⇒ MULTISAFE® double hose-diaphragm pump
   with double valves

Working principle of FELUWA MULTISAFE® pumps

The rotary driving motion of the pump gearbox is converted into a reciprocating action of the crosshead by means of the crank drive. The crosshead is connected to the piston or plunger, respectively. By means of hydraulic fluid the piston actuates a pair of redundant hose-diaphragms, which are arranged one inside the other. They not only enclose the conveyed fluid in a linear flow path, but also provide double hermetic sealing from the hydraulic drive end. The conveyed fluid will neither come in contact with the pump head nor with the hydraulic area.

For general process engineering applications, the hydraulic fluid normally consists of hydraulic oil. As an alternative option, non-compressible fluids with physiologically harmless lubricants are applied, which are compatible with the conveyed fluid. Pumping action is effected by displacement of the inside volume resulting from contraction of the hose-diaphragms. Unlike so-called peristaltic hose pumps with mechanical drive, the hose-diaphragms of the MULTISAFE® pump are not squeezed. In step with the piston stroke, they are only subject to pulsating action, comparable with that of a human vein. Elastic distortion of the hose-diaphragms is path-controlled and effected in a concentric manner due to their inherent construction.

As a result of hydraulic support, the hose-diaphragms are subject to little load even under high working pressures. The service life of hose-diaphragms is considerably extended beyond that of traditional flat diaphragms, which reflects in very good MTBF (Mean Time Between Failure) and MTBR (Mean Time Between Repair) values.

MULTISAFE® double hose-diaphragm pump, triplex design

The main advantages

To avoid this direct medium-metal contact, a flexible hose-diaphragm is inserted into the pump housing. The slurry is fully enclosed by the hosediaphragm and led in a linear flow path from the suction valve to the discharge valve. The connection between hose-diaphragm and piston is provided by a non-compressible liquid. However, piston pumping systems, as described above, have a great disadvantage: The slurry is always in contact with piston and sealing system. Abrasive fluids will reduce the lifetime of the seals. Special materials, like duplex stainless steel, have to be chosen for the pump housing when pumping corrosive media, e. g. tailings with sea water. Using a piston pump for these applications will result in high costs for wear parts and maintenance and low availability of the system.

Types of MULTISAFE® Pumps

Crank drive type SG 70 - 250<br> Driving Power 7.5 kW to 150 kW
Crank drive type DG 130 - 500<br>Driving power 60 kW to 1300 kW
Crank Drive type TG 40 - 200<br>Driving power 3 kW to 100 kW<br>Crank drive type TGK 250 - 500<br>Driving power 220 kW - 1500 kW
Crank drive type QGK 250 - 500<br>Driving power 815 kW to 3500 kW

Quintuplex Design

MULTISAFE® double hose-diaphragm pumps are designed with relatively narrow cylindrically shaped pump heads when compared to standard diaphragm piston pumps and therefore allow for the arrangement of five single-acting plungers in parallel.

When considering high flow and pressure rates, quintuplex design would not be economical for traditional diaphragm piston pumps because circular flat diaphragms would require a gearbox design that would be excessively wide to accommodate the size of the heads in parallel. Quintuplex configuration offers unprecedented uniformity.

All series are available both in upflow (from the bottom to the top of the pump) and downflow (from the top to the bottom of the pump) configuration.



Capacity of quintuplex series QGK

Unique uniformity of quintuplex MULTISAFE® double hose-diaphragm pumps

For high flow rates, by far the highest efficiency and lowest irregularity is achieved by means of single-acting five cylinder pumps. Quintuplex configuration not only allows for uniformities comparable with that of centrifugal pumps, but also contributes to a reduction of valve wear to an extent that has not been feasible thus far.

Even without pulsation dampening, the irregularity of single-acting quintuplex reciprocating pumps is reduced to 5.1 % (vs. 23.0 % of single-acting three cylinder pumps and 32.5 % of single-acting four cylinder pumps). The irregularity of 5.1 % is to be considered as a theoretical value, which does not yet make allowance for additional compensation as a result of gas content included in the hydraulic oil and the medium.

Redundancy of pulsation dampening equipment is all the more advantageous as the negating of manually or automatically operated dampening devices is a great benefit as they are usually mandatorily employed when operating at variable discharge pressures.

Singe-acting five-cylinder pump

Daniel Hagnbuchner

Regional Sales Manager
North and South America, Africa
Phone: +49 (0) 6594 10 109
Fax: +49 (0) 6594 10 200
E-Mail: hagnbuchner[at]feluwa.de

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