TSS s.r.l. Engineered Coating Solutions
TSS, Thermal Spray Services offered for the Pump Industry
Pumps and plungers are an integral part of industrial equipment and any fault in them can automatically translate into a production outage. Pump components are also more susceptible to corrosion and wear since they bear considerable abrasion.
• Impeller and Pump Casings When corrosion and wear resistant coatings are sprayed on impellers and face plates, a remarkable extension in life of the components is noted.
• Pump Plungers Areas of Pump Plungers which are susceptible to wear and corrosion are coated with corrosion and wear resistant like tungsten carbide and ceramics in order to provide protection and extend service life.
Impeller and Pump Casings When corrosion and wear resistant coatings are sprayed on impellers and face plates, a remarkable extension in life of the components is noted.
The plunger is the component of a power pump which normally requires most frequent replacement. The high speed and frictional load of the packing wear the plunger surface.
For longer life, plungers can be hardened or coated with a wear-resistant material.
Pump Plungers Areas of Pump Plungers which are susceptible to wear and corrosion are coated with corrosion and wear resistant like tungsten carbide and ceramics in order to provide protection and extend service life.
The most popular material of plunger for low temperature/low pressure salt water, chemical, and metering applications, is ceramic. It is excellent for corrosion and abrasion resistance while extending packing life. Recommended pumpage max temp 180°F and max pressure 2,000psi.
Are recommended for amine, glycol, fresh water, gasoline, or any other fluids requiring restricted lubrication that is not abrasive. Recommended pumpage max temp 600°F and max pressure 10,000psi.
•TUNGSTEN CARBIDE (TC)
Tungsten Carbide plungers are essentially upgraded Hard-Co plungers. This premium alloy coating gives more wear resistance than standard Hard-Co plungers, but with slightly less resistance to corrosion. TC plungers can be used in high temperature applications, up to 500°F and up to 10,000psi.
Corrosion and erosion are the primary causes of metal loss in pumps unless abrasion or cavitation is present.
Corrosion is primarily an electrochemical reaction occurring between the metal and the environment that causes the anodic metallic ions to go into solution.
To prevent this, a film or barrier coating may be applied that dielectrically insulates the metal surface, which contains anodic and cathodic regions, from the corrosive media.
Neutral Barrier Coating
Neutral materials such as alumina or chromium oxide ceramics provide excellent corrosion resistance to most corrosive environments by exclusion of the environment from the substrate. Generally a neutral material will not accelerate the corrosion of the substrate even if the coating is somewhat porous, although any corrosion of the substrate interface with the coating should be avoided to prevent coating separation. Sealing or impregnation of the thermal sprayed coating is recommended. Thicker and less porous layers have better barrier properties to the substrate and therefore exhibit superior performance.
Cathodic Barrier Coating
Cathodic Barrier Coatings are coatings which are cathodic with respect to the substrate material. A stainless steel or nickel alloy coating would be cathodic to a steel substrate. Cathodic coatings can provide excellent corrosion protection. However, there are limitations; there must be a complete barrier to substrate from the environment. If the substrate is exposed to the corrosive environment, the substrate will become the anode and corrosion will be dramatically accelerated resulting in spalling of the coating. Sealing or impregnation the coating is recommended. Thicker and less porous layers have better barrier properties to the substrate and therefore exhibit superior performance.
Anodic coatings for the protection of iron and steel substrates are almost totally limited to zinc and aluminum coatings or their alloys. Where coatings anodic to the substrate are applied, the corrosion protection is referred to as cathodic protection or sacrificial protection. The substrate is made to be the cathode and the coating the sacrificial corroding anode. An ordinary thermal sprayed coating of zinc or aluminum although somewhat porous, to a large extent excludes the environment and provides cathodic protection. Where desired the porosity can be sealed with organic sealers, or the coating painted, which can in some cases prolongs the life of the protective system by increasing the barrier effect. This method is generally regarded as providing superior corrosion protection versus galvanizing, plating and painting without excessive cost penalties.
TSS s.r.l is unique in its ability to work with its customers and provide them with a custom engineered solution for their specific surface engineering requirements.
Due to our vast 30 years experience in the field of thermal spray coatings as well as the capabilities of our laboratory facilities, engineering department, and machining facilities, TSS s.r.l is highly capable of assisting you in any phase of thermal spray coatings.