Metal Blowing through Vacuum or Vent Block

Possible Cause

Solution

Excessive Metal Velocity

If metal exits the runners from the cavity to the Valve-Less Block with excessive velocity, it can washout the steel of the critical flow area and result in sticking. Midland recommends a minimum of five 90 degree turns in the vacuum or vent runners before reaching the inlet of the Valve-Less Block(s). Midland will provide a recommended vacuum block runner layout free of charge for any die using Midland Valve-Less Vacuum Blocks.

Damaged Block It is recommended to periodically check the critical flow area of Valve-Less Blocks in order to ensure that there is no damage to the teeth. Pits, nicks, and broken teeth can result in sticking. If the block appears damaged, remove and replace with a new block.