DMSF seal the answer at South African plant

With Sean Reynolds

Vehicle production was shutting down on a regular basis at a South African car plant as overheating caused the faces of a competitor’s seal to break. AESSEAL South Africa technical sales manager is Sean Reynolds.

What was the main problem the company was facing and how long had they been struggling to find a solution?

On the initial green field project, the project house chose a competitor as the selected seal company, and they were tasked with sealing up the e-coat application. During this phase of construction and commissioning, which spanned over eight months, the engineering house were losing seals around every two weeks.

In South Africa we struggle with loadshedding, and due to the loadshedding, the entire plant goes down. As the plant had not yet accounted for backup systems, the competitor’s systems were inadequately cooling the seal and maintaining the differential pressure. The seal ran at an average 46C, the heat generated carried into the product, thus solidifying it between the faces, and contributing to face bonding.

Can you explain a bit more about how vital the protective finish is in car production and why it was solidifying?

The e-coat is the most critical application in the plant, as the e-coat is the final coat to the chassis of the vehicles. If my memory is correct, the margin for the product to solidify is outside 32-40C, anything colder and hotter and you have a possible solidification of the product. I need to mention, the e-coat is a very expensive product according to the car manufacturer, and by losing a seal they need to immediately stop the line, and clean out the pipework and pump, as the coating could solidify in there.

How big a problem is this in car production?

This problem causes total stop in the production.

Was the solution instant?

No, we experienced a seal failure on the inboard faces of the DMSF seal as we selected silicon faces as per guidance from the portal, but we realized even with a very effective cooling and differential pressure from the Plan 53A we still had the slightest bonding on the chamfer of the faces, therefore we decided to change the faces to tungsten, and this solved the problem.

Was the installation of the DMSF or the changing of the face combination the biggest factor in solving this problem?

Both. The DMSF generated far less heat than the competitor, thus reducing the risk of product solidification in the pump, as the seal was running super cool and within the desired margin, and we needed to change the faces to a more resistant face.

Was this an existing customer? Did they approach AESSEAL and how pleased were they with the work?

They were not an existing customer, but the engineering house contacted me and requested me to visit the site, as this problem was causing a huge financial loss to him. They were very pleased.

Due to solving the problem, the end user only uses AESSEAL now, and the engineering house has made AESSEAL their prime selection for future projects.

How much money will this have saved them and has AESSEAL received any more orders as a result?

According to the client’s statement, it has saved millions of rand (one million rand equals $58,400). We have received an order for a backup seal on the e-coat and continue to receive orders for their other applications as we are replacing the competitor’s seals as they fail. However, since the seals are still functioning on the e-coat, we have not replaced the e-coat seals since resolving the issue.