T.E.A. PLUS® coating

Ternary Eco Alloy Plus®: Teatura treatment


The surface treatment TEA PLUS® Ternary Eco Alloy deposits an environmentally friendly intermetallic alloy of tin (67%) and nickel (33%) with an Sn–Ni ratio of 1:1. It yields semi-glossy, extremely passive deposits, free of micro-cracks and with excellent guarantees of resistance to wear.


It complies with international drinking water limits:

  • EN 16058: Rig test (26 weeks).
  • NSF 51.
  • EN 16889: for professional coffee machines and other devices for the food & beverage sector.
  • Directive 98/83/EC and recent EU guidelines on safe drinking water (Council Conclusions on EU Human Rights Guidelines on Safe Drinking Water and Sanitation, 17 June 2019).

Resistance to corrosion

  • 24 hours immersion in HCl, H2SO4, HNO3, NaOH: no corrosion.
  • Salt spray test NaCl 5%: no corrosion (EN 248).

The TEA+® coating is generally applied after the RUVECO® lead stripping process to prevent the progressive deterioration of brass, which in components subjected to extreme working conditions, such as steam passage above 100°C or frequent descaling cycles, feeds the circulation of lead in water or in the liquids that it comes into contact with.

December 2020: TEA PLUS® has been approved by the German Federal Environmental Agency (Umweltbundesamt - UBA) and included in the “4MSI Composition List”.
This list defines the metallic materials approved in the member states of the 4MSI group (Germany, UK, Netherlands, France and Denmark) as suitable for use in contact with drinking water.
In the downloads section at the bottom of the page you can find the updated “Positive List”, where on page 40 our Sn/Ni coating is included among the “platings”.
To view the “Positive List”, please see the downloads area below.


  • Thickness 2–4 µm
  • Hardness 400 HV
  • Free of impurities and organic pollutants
  • Corrosion resistant
  • Prevents oxidation of the material
  • Valid alternative to classic nickel, nickel + chrome, electroless nickel deposits
  • Frame treatment
  • Rotary barrel treatment


  • Minimum dimensions: a few millimetres
  • Maximum cylinder dimensions: 1850 mm – ø 450 mm – weight 450 kg
  • Maximum dimensions of parallelepipeds: 1.850x450x1.300 mm – weight 450 kg


  TEA PLUS® Ni–Cr Base
material / brass
Nickel release in H2O: LOW LOW HIGH LOW
Lead release in H2O LOW HIGH HIGH
Resistance to corrosion GOOD GOOD LOW
Internal deposit GOOD LOW N/A
Homogeneity GOOD LOW N/A


Nickel release in H2O: LOW
Lead release in H2O: LOW
Hardness: HIGH
Resistance to corrosion: GOOD
Internal deposit interno: GOOD
Homogeneity: GOOD


Nickel release in H2O: HIGH
Lead release in H2O: HIGH
Hardness: VERY HIGH
Resistance to corrosion: GOOD
Internal deposit: LOW
Homogeneity: LOW

Base material / brass

Nickel release in H2O: LOW
Lead release in H2O: ALTO
Hardness: BASSA
Resistance to corrosion: LOW
Internal deposit: N/A
Homogeneity: N/A


  • Food Sector: complements for coffee machines and vending machines (boiler cover, boiler flange, heating element flange, slot, cover plate, interface bushing, plate, double cone, block, heating element hose barb fitting, spray housing, nipples, boiler, unit body, tap unit, filter housing unit, dispensing unit, hook ring, fitting, injector, cap, mushroom button, level unit, spear valve, valve body, perforation ring, picking tube, spray housing, adapter, fitting, diffuser, sleeve, tube coupling, distributor, manifold, valve hood, pre-infusion chamber cap, injector fitting, gilgeur)
  • Food Sector: complements for ice makers (evaporator, evaporator unit, modular evaporator, CS evaporator)
  • Food Sector: beer taps and gassers (blending taps, taps, valve, tap heads, reducer)
  • Plumbing Sector (fitting, boiler, heating element, distributor, distributor, by-pass body, hydraulic components, fittings for circular heat exchangers, thermostatic valves, ball valves, manual valves, mixing valves, meter boxes, volumetric meter, fitting, metering device, reducer, elbow, cap, reduction, sleeve, tee, curved fitting, straight fitting, compression fittings, hose barb, washer, manifold)


In this section you can download the PDF for the specific process.


What materials can be processed?

It is applied directly on copper, copper and nickel alloys, white bronze (RONALLOY™ GT 300 / T.E.A.® B) and silver.

Is it durable with so little thickness?

Thicknesses of 2-4 microns, thanks to the extreme passivity of the coating, which is free of micro-cracks, guarantee a long service life and resistance to descaling or acid cleaning cycles, as well as hot water and steam.

Is this a repeatable process? Will the colouring of the parts vary between deliveries?

One of the guarantees given by this carry-over is the very high repeatability and consistency of the colour over time, as well as the uniformity of the colour between batches.

When should TEA PLUS® be applied?

After machining and before assembly.

How many types of TEA are there?

TEA+® is an intermetallic Sn (67%) – Ni (33%) alloy; Sn–Ni ratio 1:1;
RONALLOY™ GT 300 / TEA® B is a deposit of Copper (62%) and Tin (38%) --> Cu3Sn

What are the regulatory limits for lead contamination in drinking water?