Plate mate: the niche of hydraulic part re-plating
Rajeev Daswani discusses the growing scope of re-plating in the aftermarket and the role of Marami Metal Plating in reconditioning hydraulic components
As industries across the world search for cost-cutting measures, one growing segment is the market for re-plated parts — a sub-segment of the re-manufactured parts industry that is particularly suitable for the restoration of hydraulic components.
According to a report by Mordor Intelligence, the global metal finishing market is estimated to be growing at a compound annual growth rate of 6.5% and is expected to reach $101.9bn by 2020, up from just $69.8bn in 2014.
Replacement parts for heavy hydraulic machinery are increasingly available from various countries such as China, India and Italy at various price points — but they are often an inadequate replacement for the original parts and can result in greater costs being accrued due to faster wear and tear.
Rajeev Daswani, MD of Marami Metal Plating, says: “We service a large variety of hydraulic pistons and cylinders of various sizes that tend to be heavily damaged once they come to us. We find damages could have been prevented if a proper service schedule was maintained, and if the parts were serviced at regular intervals.”
Replacement chrome bars for hydraulic systems are a good example. While cheap, replacements typically often come with a protective metal coating of only 25 microns that, depending on the profile of use, could wear quickly and lead to higher expenses incurred from regular maintenance and downtime.
Alternatively, companies can opt to restore the original parts by re-applying a thicker layer at a bare minimum of 200 microns of hard plating in original base materials — such as chrome — to prolong working operations and decreases the frequency of maintenance and downtime losses.
Daswani continued: “We see hydraulic repair companies simply check to see if the existing chrome is passable. Once they find that the chrome in the cylinder and piston is fine, they change the seals and re-assemble the parts. Although this is very common, a more proactive approach is better.
“Cheaper replacement parts can be of inferior quality. These parts could not only wear away easily due to the lower thickness of chrome, but also potentially damage a unit, resulting in severe losses.”
For some contractors and asset operators, reconditioning original parts in order to both increase the longevity of the part and protect the integrity of the machine as a whole can ensure better longterm productivity and a higher return on investment.
What proportion of Marami’s business currently involves hydraulic components, and is heavy lift machinery a growth area?
Approximately 30 to 35 % of Marami’s business currently involves hydraulic components. Heavy lift machinery is definitely a growing part of hydraulic components.
What makes hydraulic components such a suitable category of machinery elements for the process of re-plating?
Hydraulic components are chrome-plated in order to impart the desirable properties of chromium as a metal. These include a high hardness coefficient, low friction coefficient, low wearability, high oil retention capability, and high corrosion resistance.
Hydraulic components work under tough conditions which result in the wear and tear of the chrome coating over a period of time, thus affecting the performance of the equipment. In such cases, it is always advisable to opt for re-plating to pre-empt oil leaks or a complete breakdown of hydraulic components.
Do you have any case studies or examples that you can provide for the advantages of re-plating over replacement parts?
At Marami, we plate both original and replacement parts. In both cases the thickness of coating is applied in line with what is required for the parts to be correctly re-assembled and to functional mechanically. The main advantage of original parts as chosen by the manufacturer, is that the parts itself are specially designed to fit the components and thus have better performance once we plate the part up to desired thickness.
This is not to say that replacement parts are not good, but in our experience salvaged original parts yield better end results. Many times, we find that companies replacing spare parts don’t always use the same grade base materials and that may have an impact on performance even if the part is plated.
Replacement parts typically have a coating thickness of about 25 microns, according to industry research, but at Marami we remove the existing damages, pre-grind the piece again and build up a coating of about 500 microns and then post-grind it to size. When tested, a part that has been re-plated in this manner will easily outperform a replacement part in all standard measures of the quality of chrome coating.
Marami has introduced the use of non-acidic processes, what does this change?
Marami has moved away from using large amounts of acid to remove old coating: we now use as little acid as possible and use machining alternatives. This is better for the environment, but does takes more manhours and therefore increases the cost for us. On the other hand, however, we have lower costs related to the storage and disposal of acid. However, the hard chrome plating removal process itself requires a bath that contains chromic acid — this cannot be prevented.
Is the general industry trend towards greater automation relevant to re-plating?
Chrome plating is a highly evolved process and the industry has been stable for a long time. While automation does provide consistent results, one needs to keep in mind that every part that is re-plated has unique requirements and has different sizes and configurations.
Automation is valuable as it enables a higher output, which then reduces cost through economies of scale. This is applicable when you have a standardised product, but it becomes challenging to apply to multiple product types as each product type is jigged separately and has different parameters to follow to attain the required plating.
However, automation of a standardised product can be beneficial as it enables plating companies to plan a robotic process that carries out the functions to meet the end needs, while ensuring you can meet the higher volume required by your clients.