Technical Support

Here is the new GemmeCotti video tutorial: how to assemble and disassemble mag drive centrifugal pump HTM PP/PVDF. Click here or on the image below to watch the video

MAIN FEATURES OF MAG DRIVE PUMPS HTM PP/PVDF

Mag drive centrifugal pumps series HTM PP/PVDF are chemical seal less pumps suitable to pump high corrosive fluids and are made of polypropylene or PVDF. These kind of pumps for acids has a special design in which the transmission of the motion occurs through magnetic joints (external magnet and internal magnet) without any mechanical seal. The external magnet is placed on the drive shaft and transmits the motion to the internal magnet connected to the impeller which rotates and moves the liquid through the pump.

This simple structure guarantees a very reduced maintenance with consequent save in terms of repairing and spare parts costs during the pump life.

Watch our video tutorial for more information!

When you have to unload a tank truck or an IBC container you need to use a suitable pump resistant to corrosion that can be easily moved. That’s why we designed a pumping system which is portable and composed of chemical resistant mag drive centrifugal pump series HTM PP/PVDF. The peculiarities of this device are that it is flexible for different uses, and it is portable.

The pump is placed in a proper structure that can be removed from an IBC container’s attack and connected to another, thanks to quick couplings, ensuring anyway all of its functionalities.

The displacement of the pump is easy and rapid, as a result of its compact shape and its practical handles, located on the top. The system includes a control panel composed by illuminated start and stop pushbuttons, a red LED for power on, an emergency stop button with manual restoration and a flexible supply cable with CEE plug. There is also a specific container in order to collect dropping fluid. As an optional, it is possible to order a dry running protection device and a frame with wheels for an even easier portability.

FEATURES OF THE PUMP

Materials available: PP and PVDF
Max capacity: 13 m3/h
Max head: 14 m
Standard motor: 0,55 kw, B3/B5, 2poles, single phase, 230V, 50-60HZ
Baseplate: included

 MAIN APPLICATIONS: UNLOADING TANK TRUCK AND IBC CONTAINERS

The pump is generally part of a hydraulic system that can include a various number of components such as valves, fittings, filters, expansion joints, instruments, etc. The way the piping is arranged and the position of the components has a great influence on the operation and on the life of the pump. Here are five things to keep in mind when installing a pump in a plant:

1. Locate the pump as near as possible to the liquid source and under the level of the liquid (in case of non self-priming pumps). Always use pipes as short and straight as possible and limit the number of bends assuring radius of curvature as large as possible. This would avoid air vortex that can be created in the long piping line. Avoid the creation of siphon also before the suction of the pump.
2. Do not load the pump with the weight of the pipes. The piping should be properly supported and kept in line independently from the pump, until its connections, so that the piping doesn’t exert loads on the pump.
3. The sizes of the suction and discharge pipes have to be at least as large as the inlet connection of the pump. Diameter restriction of the suction pipe is responsible and cause of the cavitation of the pump, creating a loss in the performance of the pump and a rapid wear. It’s advisable always to use (if in case) flexible reinforced pipes that don’t collapse under a situation of depression
4. A check valve should be installed on the discharge pipe to avoid the liquid to flow back when the pump is stopped.
5. The suction line has to be clean and/or contain a filter to protect the impeller from damage due to impurities, or other foreign particles, especially when starting the plant for the first time.
6. Don’t use metallic piping with plastic pumps to avoid cracks on pump connections and make sure that the connections are properly tightened otherwise the suction capacity will be reduce

The easy rules written above are very important for the correct installation of a pump but if you want to check also the correct functioning you could:

1. Install a  proper pressure gauge on both the suction and discharge piping which allows a control of the functioning in relation to the required working point. In case of cavitation or other dysfunctions, the gauges will show evident pressure fluctuations.
2. Install a wattmeter to monitor the electric power absorbed by the motor to avoid dry running of pumps.

Few precautions can prevent pump failures and consequent losses of time and money for repair.

In applications where chemicals, acids and corrosive liquids are involved it’s necessary to pay a great attention to the kind of pumps used and sometimes it’s difficult to choose between seal or sealless pumps. So which are the advantages and disadvantages of mag drive sealless pumps in comparison a with mechanical seal pumps? This is the neverending debate for pump manufacturers and pump users and in this article I would like to point out some aspects to keep in mind when choosing the pump design.

MAG DRIVE PUMPS

Mag drive pumps have a particular sealless design where the pump is closed coupled to the motor. The external magnet placed on the drive shaft transmits the motion to the internal magnet connected to the impeller which rotates and moves the fluid through the pump. The external magnet and inner magnet are separated by a rear casing that creates a hermetic containment of the liquid that has no access to the outside

Advantages

1. This special hermetic pump design prevents any leakage of fluid and fugitive emissions, that in case of chemicals, corrosive liquids, explosive and flammable fluids could be very dangerous for people dealing with the pump and especially for the environment. So mag drive pumps allow to follow strict environmental and safety objectives required by many regulations.  We shouldn’t forget also that some liquids could be very expensive and their loss due to a seal failure may cause high unnecessary extra costs.
2. Mag drive pumps are very reliable and need very low maintenance thanks to their simple design. With normal working conditions these pumps can work without any kind of repair for more than a decade so their life cost is highly reduced  even if it’s always better to check o-rings and bearings every one/two years just to be sure that there is no wearing.
3. The coupling is very easy because there is no need for a motor/pump alignment.

Disadvantages

1. In applications involving even a small percentage of solids the mag drive system is not the suitable solution. Magnetic drive pumps, in fact, can work only with clean liquids without solids in suspension.
2. Magnetic drive pumps are usually more expensive than mechanical seal pumps. However, as written above, the maintenance costs are very reduced during the life of the pump and these long-term financial advantages should be considered when choosing the pump design.

MECHANICAL SEAL PUMPS

The seal in mechanical seal pumps is composed by a static ring and a rotating ring placed on the pump shaft which is directly coupled to the motor shaft. The two surfaces sliding together need to be lubricated and the seal lubricant is the liquid itself that is being pumped.

Advantages

1. Mechanical seal pumps are the perfect solution for applications involving solids in the liquid (for example waste water treatments) because their design with open impeller allows to pump very dirty liquids and fluids with high viscosity.
2. The cost of this kind of pumps is lower in comparison with mag drive pumps so, if the financial aspect is critical when choosing the pump, sealed pump may be the right selection.

Disadvantages

1. Seals are often the weak point in standard pumps because they are the first cause of failure in a chemical process. When a mechanical seals fails it allows the liquids to escape causing dangerous leakage.
2. Considering the point above, to avoid harmful events and dangerous leakage it’s necessary to plan a periodical maintenance of mechanical seal pumps to check the status of the seal and replace worn parts. In this case the costs of maintenance of these pumps could be higher than those of mag drive pumps.

In some applications it’s possible to install both mechanical seal or mag drive pumps and technicians can decide according to the advantages and disadvantages of each pump which is the best for them.

In my latest article about the different materials used for chemical pumps I wrote a brief guide helpful for a first materials selection according to their properties and characteristics. Now I would like to analyze each material from the point of view of their typical applications.

Polypropylene (PP):

Mechanical applications: PP is used for mechanical parts in corrosive environments. Compared to polyethylene with a high molecular weight, polypropylene has a higher traction resistance.

Alimentary applications: physiologically inert when it has a natural color, polypropylene is suitable for  use in contact with foods.

Electrical applications: good dielectric characteristics and weather-proof.

Chemical applications: PP is widely used in chemical industries because of its high resistance to acids and alkali. Thanks to its higher resistance to temperature than PVC  it’s used for valves, flanges gears etc. in chemical, galvanic and petrochemical industry. It’s not suitable for use with high concentration oxidizing acids.

PVDF:

Chemical applications: the high chemical resistance to acids and alkali is typical of fluorinate polymers (PVDF) that’s why it’s mainly used for parts in petrochemical and chemical industries.

Alimentary applications: physiologically inert when it has a natural color, it’s approved by different organizations for use in contact with foods. It’s often used because of this characteristics, especially in alimentary machines and in pumps for alimentary liquids.

Electrical applications: good dielectric characteristics, self-extinguishing without adding halogens and weather-proof

Mechanical applications: the low friction coefficient makes is suitable for bearings even if they work in water.

PTFE

Mechanical applications: the low coefficient of friction makes it useful for bearings unless they have to support a great weight.

Alimentary applications:  physiologically inert, it’s approved for use in contact with food by some organizations, but in some countries it’s questioned the possible use in contact with food.

Electrical applications: thanks to the good dielectric characteristics, the self-extinguishing and the stability to bad weather it’s used more and more in this field.

Chemical applications:  typical of fluorinate polymers is the high chemical resistance to acids and alkali. It’s main use is for components in petrochemical and chemical industry.

EPDM

Mechanical applications: Gaskets, section bars and technical items for cars, handmade articles for anti-acid protections.

AISI316

Suitable for plants for production of nitric and sulphuric acid and for the relative equipment (pumps, valves and pipes). It’s used in very aggressive environments (textile industry, paper industry, oenological- alimentary  industry, and especially naval industry).