The heating jacket keeps the pump hot when used for processing liquids that solidify at room temperature such as bitumen, fats, paraffin, molasses. The jacket is made up of an interspace that is connected to the hot water, hot steam or hot oil line. In pumps of the L series with external seal, the heating jacket is also installed in the rear part of the pump for keeping the seal area hot. The heating jacket is also provided for magnetic drive pumps where, in addition to the interspace on the pump body, a special double layer containment can is installed for heating up the rear part of the pump where the magnetic drive coupling is placed.
Although our pumps are also able to work with liquids containing solid parts, sometime the installation of a suction prefilter can be preferable, in order to prevent very large solid parts from entering the pump. The prefilters are produced by Belli Meccanica and sized according to the pump flow rate and the viscosity of the liquid, in order to minimize the pressure drop in suction side and to preserve the self-priming capacity. They are equipped with a removable cover and with a practical removable filter basket in order to make cleaning operations quick. The filtration diameter is generally 5-8mm, but we also make filters with thinner mesh, up to 0.5mm, if there are specific filtration requirements for the liquid. The prefilters are also made in Aisi 316 stainless steel for applications with aggressive liquids or food grade liquids.
Integrated VFD on motor or mechanical speed variator
Our pumps are volumetric, therefore it is possible to control the pump flow rate simply by changing the rotation speed. This can be done in two ways: by varying the rotation speed of the motor with a VFD inverter or by using a mechanical speed variator placed between the motor and the pump. In the first case, the motor is equipped with a VFD inverter complete with a control keypad installed on board instead of the terminal block. This system allows an electronic variation of the motor speed ensuring high efficiency and the possibility of interfacing the pump to any external control plc. In the second case, a mechanical speed variator is used and by a control knob it’s possible to regulate the pump speed. In case of applications in Atex zone 1 areas, hydraulic speed variators are installed.
Our pumps have a structure with the gearmotor connected by flange and this configuration ensures that the gearmotor-pump alignment is always perfect and avoids any possibility of alignment errors during the assembly. The structure of the pump therefore does not require an elastic joint to compensate any alignment mistake and not even any baseplate since the gearmotor is not supported on feet but by the coupling flange. However the baseplate is supplied as an option in case the pump must be placed on a not very stable or not homogeneous ground or when there is the need to adapt the flanges to a certain height from the ground. The baseplates are custom made in painted steel frames and on request also in stainless steel.
Flanges and connections
The flanges of our hollow disc pumps are standard according to UNI PN10 and iron or stainless steel flanges and gaskets are available from stock. For all our pumps on request we supply adapters for american standard Ansi 150 flanges, but also for other types of connections that are widely used such as Garolla, Clamp or hose connectors. We create custom adapters and piping sections to make the pump compatible with existing pipes. We also supply axial compensators with stainless steel bellows.
We design and manufacture electrical panels, also according to the Atex zone 1 standard, which can be installed with the pump on trolley or on skid or placed beside the pump on a wall. The panels are equipped with start, stop, reverse control and speed indicator, so that the pump can be controlled in both directions of rotation. The panels are designed by our technicians according to the requirements of the customer and can be equipped with VFD inverter for speed regulation and can be connected with control instruments such as pressure switches, flow meters or level gauges. We also develop advanced 4.0 integrated solutions with programmable PLC interconnected to the factory network by using special dedicated software and man-machine interface.
Trolley with wheels and electrical panel
The pumps can be equipped with a 3 or 4 wheels handling trolley so that they can be easily moved within the work area with versatility of use. The trolleys can be also equipped with filter, electrical panel, collection tray and parking brakes, becoming therefore a mobile skid or a filtering trolley. The structure of the trolleys is made of painted galvanized steel or of stainless steel frames to ensure maximum resistance to oxidation in any work environment. Wheels are supplied in oil-resistant rubber or white nylon depending on the type of flooring. The whole arrangement consisting of pump, trolley, electrical panel and accessories is also made according to the Atex directive for zone 1 for explosion risk areas.
Bypass psv valve
The PSV maximum pressure bypass valve is an important accessory to be installed when there is a risk that the pump delivery pipe may be accidentally closed. Since our pumps are positive displacement, their flow rate does not depend on the delivery pressure, therefore even with discharge side closed they maintain their flow rate unchanged, consequently increasing the pressure up to values that can be harmful for the pump itself or for the system. The bypass valve produced by us is supplied as an accessory that can be installed on the pump and it’s calibrated so that it starts operating in case of overpressure by recirculating the liquid in suction. The bypass valve is bidirectional, i.e. it works in both pump operating directions and can be standard or with adjustable setting.
Full recirculation bypass valve
The psv bypass valve has the function of recirculating the flow in suction in the event of temporary overpressure, it is therefore a safety device that must only work if the pump delivery is accidentally closed. If on the other hand the delivery side must be closed repeatedly without switching the pump off, such as for example to carry out a dosage or to interrupt a loading operation, it is necessary to install an oversized bypass valve capable of recirculating the entire flow not only in the case of accidental closures. Our bypass valves have an innovative structure that makes possible to orient two passage holes in the same direction, thus obtaining a double passage section, or it is possible to stack two bypass valves, thus having up to 4 passage sections in the same direction, so obtaining a total recirculation bypass valve suitable for the purpose.