We recently got a quality complaint from customer that the hydraulic rod was burn during working, see below photo.

After analysis with our engineering team, we call this “Diesel Effect”. We’d like to discuss about this.

What is the “diesel effect”?

The diesel effect occurs in a hydraulic cylinder when air is drawn past the rod seals, mixes with the hydraulic fluid and explodes when pressurized.

How does this happen?

Generally the gas in the cavity cannot escape and release heat after being pressed, this is one of the problems that often occur during injection mold testing.

The main manifestation of scorching is: the dark or black dots of the product near the end of the flow or the wind-enclosed area.

The main causes of scorching:

1. Poor exhaust.

2. Running speed is too fast.

3. The temperature is too high.

4. Hydraulic seals Manual Installation error etc.

How to avoid“diesel effect”?

1.   Check all working parts of the cylinder periodically.

2.   Keep the oil in the cylinder clean at all times.

3.   Seal selection to avoid trapped pressure situation.

4.   Pay attention to exhaust before operation.