plastic pumps

Plastic pumps: characteristics and advantages

GemmeCotti plastic pumps for acids and dangerous liquids

GemmeCotti has been producing pumps for acids and dangerous liquids for over 30 years in special materials: plastic pumps are mainly made of PP (polypropylene) or PVDF and stainless steel pumps are mainly made of AISI 316. The use of these materials ensures compatibility with a wide range of liquids such as acids, bases, oils, alkalis, refrigerants and fuels. 

In this article, we will focus on the plastic materials used for the complete range of our chemical pumps. We will analyze their main features and discover why plastic pumps are especially suitable for pumping corrosive and dangerous liquids such as sulfuric acid, sodium hydroxide, hydrochloric acid, acetone, cleaners, petrol, diesel, phosphoric acid and seawater.

Most of the PP and PVDF injected plastic parts used in GemmeCotti pumps are manufactured by Gemme Plast, a part of the GemmeCotti group, which specializes in the injection molding of plastic materials

Features of the plastic materials 

Our pumps are often used with fluids that can be corrosive and very aggressive, so it’s very important to use highly resistant and compatible plastic pumps. The pumps made of plastic materials are: 

Polypropylene [PP] pumps

PP (Polypropylene) is the main plastic material we use for our pumps. It is one of the most common polymers and, historically, one of the first to be used in industry.
Polypropylene was discovered in 1954 by Italian chemical engineer Giulio Natta, following the work of Karl Ziegler in Germany. Their innovative studies on stereospecific polymerization, which led to the discovery of crystalline polypropylene, earned them the Nobel Prize in Chemistry in 1963.
PP is highly resistant and therefore can be used with many fluids like caustic soda (or sodium hydroxide) and acid liquids. Polypropylene is reinforced with other materials like glass fiber and talc to make it more mechanically resistant and to ensure a higher resistance to pressure.
Polypropylene is perfect for obtaining injection molded parts, and the pumps made of this material can safely withstand fluid temperatures of about 60-70°C.

Plastic pumps in PVDF 

The second most important material we use for GemmeCotti plastic pumps is PVDF, which is a fluoropolymer, i.e., a technopolymer with advanced properties. Its composition makes it chemically inert to most chemicals. Since this kind of plastic is difficult to synthesize and is used in more limited and specialized sectors, it costs more than PP. However, It is significantly more resistant to high temperatures compared to polypropylene and it can be used at higher temperatures, up to 90°C.
This material too is reinforced to increase its mechanical resistance

How to choose the most suitable pump material

In order to decide whether PP, PVDF or stainless steel AISI 316 is the most suitable material you must:

  • first, know the liquid that has to be pumped, which is in contact with the pump and verify its compatibility. You can use the GemmeCotti chemical compatibility chart available at this link;
  • and then know the temperatures of the liquids to be pumped. Polypropylene is the most suitable plastic material for liquids with maximum temperatures of 60-70°C, while PVDF is preferred for temperatures up to 90 ºC.  When the temperature of the liquid exceeds 90 ºC, you can check its compatibility with stainless steel AISI 316, a material that can work with even higher temperatures.

Plastic injection molding

The GemmeCotti group includes the sister company Gemme Plast, which makes injection molded parts. Plastic parts are injection molded, a production technique widely used for the processing of most thermoplastic polymers. We produce plastic parts that are used for the production of GemmeCotti pumps and that is why we are able to control the quality of our production and guarantee our customers fast delivery with significant savings.
Gemme Plast has a range of different tonnage presses, which make it possible to inject plastic parts of various sizes according to need. So we can offer pumps with a very wide range of performance, varying from 0.5m3/h to 150m3/h.

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GemmeCotti’s new website is online

We’re happy to announce that GemmeCotti’s website has been redesigned and the content updated. Now it’s more intuitive and user-friendly to help you find what you need.
Read the article to stay up to date with all the news!


Do you want to discover more about GemmeCotti pumps? On the home page of our new website, we have added the range of pumps for acids and corrosive liquids for easy and direct access to all our products. 

If you want to explore our website, we’ve made the navigation easier by adding the drop-down menu to find all the product categories, like our mag drive pumps, the best-selling GemmeCotti product.

And where can you find the main applications of our industrial pumps? Easy, always on the home page below the GemmeCotti range of pumps section.  


On the product pages of our magnetic pumps, you can find lots of changes compared to the previous version of the website:

  • Curves and technical data of each pump to let you know clearly and accurately their performances
  • Strong points of our mag drive centrifugal pumps


  • Presentation of the optional available for each type of pump (flanges, baseplates and dry-running protection device)



Are you curious to know how a mag drive pump works? On this page, we explain every detail of its functioning and all the advantages of our mag drive pumps. 

Welcome to our new website and good navigation!

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Congratulations Sofia!

On December 16th 2022 our colleague Sofia achieved an important goal: she graduated in Economics and Management!
We are so proud of her because in these 3 years spent together she has always been a bright and determined girl with passion and dedication for her work.
She decided to write her thesis project by combining her university studies and her
working experience in our company. GemmeCotti was the subject of the thesis, where she analyzed some of the main activities and aspects regarding the relationship with customers.
She could count on the precious help of the colleagues thanks to their interviews. 

We are proud of you, well done Sofia!

Sofia graduation

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Our history begins in 1992 when Enrico Gemme e Marino Cotti, after a considerable experience on chemical pumps for acids and dangerous liquids, decided to open their company: GemmeCotti srl. This year we celebrate 30 years of activity, of dreams and of successfully completed projects. Our 30th anniversary is an important goal, which we don’t consider as a point of arrival but as a leap towards the future.
We are proud of all the achievements, but we are also ready for the upcoming challenges thanks to the experience gained, always eager to improve and grow professionally, to satisfy the requirements of our customers and the stakeholders expectations.

GemmeCotti started as a small company, but gradually expanded with the establishment of the subsidiaries Armek srl in 1999 and Gemme Plast srl in 2018, a company specialized in the injection molding of plastic materials. 

The quality of our pumps for acids and dangerous liquids and our professionalism are recognised and appreciated in Italy and abroad. We supply our pumps in more than 90 countries and in these years we have established lasting relationships with our partners, sources of great pride and satisfaction for us. 

For this special event we created a new logo which contains our commitment and our gratification.





Now a new chapter begins, full of new perspectives and goals to achieve!

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GemmeCotti e-commerce is online!

We’re excited to announce the launch of our new e-commerce site.
In this online shop you can choose and buy from a variety of GemmeCotti products like HTM magnetic drive centrifugal pumps or HTT mag drive turbine pumps with the materials and the motor power that you prefer for those pumps. 

Our e-commerce includes 3 categories of GemmeCotti products: 

  1. Mag drive pumps 
  2. Accessories
  3. Spare parts for mag drive pumps


MAG DRIVE PUMPS GemmeCotti HTM scrubbers

The pumps available on our e-commerce are the magnetic drive centrifugal pumps in PP and PVDF (pump sizes available: HTM 4 , HTM 6, HTM 10, HTM 15, HTM 31) and the magnetic drive turbine pumps in PP and PVDF (HTT 2000, HTT 3000, HTT 5000).

You can find all the details about the pumps and their technical data directly on our e-commerce site so that you can choose the right pump for your needs and order it easily and quickly. Every pump is available with different motor power and corresponding baseplate so that you can order the complete pump set ready to use. 


WE htm 10


GemmeCotti can supply WE and RWE spare parts kits for HTM mag drive pumps from HTM 4 to HTM 31 PP and PVDF. So if you want to buy a pump complete with its spare parts to keep in stock for future maintenance it’s easy to have everything through GemmeCotti’s e-commerce site. 


foto accessori


In addition to pumps and spare parts,GemmeCotti provides also accessories for its chemical pumps like for example baseplates type A,B and C (material: PP), Dry running protection device and Flanges for HTM 6, HTM 10, HTM 15 and HTM 31 mag drive pumps PP/PVDF. 


  • Type A: suitable for motors IEC B3/B5 from 0,12 kw to 0,55 kw: IEC 56 / IEC 63 / IEC 71
  • Type B: suitable for motors IEC and NEMA B3/B5 from 0,75kW to 2,2 kW: IEC 80 / IEC 90 / NEMA 56TC USA / NEMA 145T USA
  • Type C: suitable for motors IEC and NEMA B3/B5 from 3 kW to 4 kW: IEC 100 / IEC 112 / NEMA 184T USA

Our e-commerce is active only in Italy and in the European Union. If you are interested in purchasing from other countries, you can contact us by email at

If you want to discover more about our e-commerce, you just have to visit our website and click on the section “Shop”!


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A new asset for the marketing team, welcome Marta

We are excited to welcome Marta on board. She will be a new asset to our Sales and Marketing team.

After studying architecture in high school, she graduated in Industrial Product Design at Politecnico of Milan. She decided to change her previous job to follow her interests. Here in GemmeCotti she will join the marketing department and she will support the colleagues of the sales team with the pumps quotations.

Dynamic and sporty girl, she loves climbing outdoors and riding her motorbike to visit new places.

Welcome on board Marta!

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Welcome Alessia to our marketing team

Today we welcome Alessia, who has just started her internship in GemmeCotti’s marketing team.

After a degree in Communication Studies, she will soon get her master’s degree in Theory and Technology of Communication at University of Milano-Bicocca. She will join our marketing and communication department to gain practical experience and she will support the colleagues in the promotion of GemmeCotti pumps.

It’s her first working experience and she’s really excited to start this new adventure.
In her free time she loves to relax watching TV series and listening to True-Crime podcasts.

Welcome Alessia in our team!

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Summer closing days 2022

We inform you that our workshop and shipping department will be closed for summer holidays from 6th to 21st August, 2022.

Please organize your orders accordingly.

The sales office will remain open for the entire month for quotations and technical support.


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We are pleased to announce that, starting from 2021, GemmeCotti is officially a European Union trade mark! GemmeCotti trade mark certificate

Our trade mark has been recorded in the Register of European Union trade marks n. 2021/097 of 27/05/2021 (visit the EUIPO ).

The trade mark identifies the pumps of our production certifying their origin and it is valid in all the member states of the European Union.

Moreover, this mark represents two key features of GemmeCotti: our full transparency and the quality Made in Italy of our products.

Discover more about us

GemmeCotti trade mark

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Happy retirement Luigi!

Luigi retirement

Today we celebrate Luigi, who retires after 5 years in our workshop.

After a long experience as self-employed and a successful job in the aircraft industry, Luigi started to work with us in 2016 becoming soon an expert in the production of GemmeCotti chemical pumps: he collaborated in the assembly operations and quality control of our products.

The long awaited moment has finally arrived: Luigi can’t wait to cultivate his passion for flying and parachuting!

Work won’t be the same without your laugh.

Thank you Luigi for your dedication, we wish you all the best.

Enjoy your retirement! Now the fun begins!




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