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Technologies

Magnetic drive technology Armek

HOW DO SEAL AND SEALLESS PUMPS WORK?

In industrial applications where chemicals, acids and corrosive fluids are involved it is necessary to pay a great attention to the kind of pumps used and sometimes it’s necessary to choose between seal or sealless pumps. Here are some aspects to keep in mind when choosing the pump design.

MAG DRIVE PUMPS

Mag drive pumps have a particular sealless design where the hydraulic part 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 which has no access to the outside.

MAIN FEATURES

  1. This completely hermetic pump design prevents any leakage of fluid and dangerous emissions, which in case of chemicals, corrosive liquids, explosive and flammable fluids could be very dangerous for people dealing with the pump and for the environment. So magnetic drive pumps allow following strict environmental and safety objectivesrequired by many regulations.  You shouldn’t forget also that some liquids could be very expensive and their leakage due to a seal failure may cause high unnecessary extra costs.
  2. Magnetic drive pumps are very reliableand 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. Therefore their life cost is highly reduced even if it’s always better to check o-rings and bearings once in a year or two just to be sure that they are not worn.
  3. The coupling of the pump with the motor is very easy because there is no need for a motor/pump alignment.
  4. 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.

 

Armek pumps series HTM PP/PVDF – HTM SS316 – HTT and HTA are designed with the mag drive system.

MECHANICAL SEAL PUMPS

In mechanical seal pumps the seal is composed of 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.

MAIN FEATURES

  1. Well known pumping system used in chemical industries for decades.
  2. Mechanical seal pumps are the perfect solution for chemical 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.
  3. Cheap solution if the financial aspect is critical when choosing the pump.
  4. A periodical maintenance is required to check the status of the seal and avoid pump failures.

Armek pumps series HCO are designed with a mechanical seal system.

PUMP MATERIALS

When dealing with acids it’s important to use chemical pumps made of suitable materials resistant to corrosion and which are highly efficient with minimum maintenance. That is why, after years of experience in the industrial pumps field, we decided to use Polypropylene, PVDF and AISI316 as standard materials for our pumps.

Every material has its own properties and characteristics which make it suitable for transferring different acids. So it’s really important to choose the right pump material for every chemical application.

 Polypropylene (PP)

  1. Polypropylene is well known with the name Moplen (™)
  2. It’s a thermoplastic material extremely resistant to many solvents, bases and acids such as for example acetone, caustic soda and chloridric acid.
  3. It’s not suitable for concentrated, oxidizing acids.
  4. It’s used in many different industries for parts subjected to relatively modest forces.
  5. Temperature range for PP pumps is from 0° to 70°C.

Polyvinylidene fluoride (PVDF)

  1. It’s a thermoplastic material of the fluoropolymer family and it’s generally used in special applications requiring high purity, strength, and resistance to solvents, acids, saline solutions, alkali and bases.
  2. It’s mainly used with liquids such as for example sodium hypochlorite, concentrated sulfuric acid, nitric acid, gasoline.
  3. It doesn’t undergo deformation under loads and has a high mechanical resistance.
  4. Temperature range for PVDF pumps is from 0° to 90°C.

 Stainless steel AISI316

  1. It’s a metallic material used when both the properties of steel and the resistance to corrosion are required.
  2. Particularly indicated for pumps working with high temperature liquids, oils, kerosene, alcohols.
  3. It’s used to pump acids up to a maximum temperature of 160°C