Valve-Less Vacuum Blocks

Midland Technologies is the Leader in Valve-Less Vacuum and Vent Technology for porosity control in high pressure die casting. From small cosmetic castings to the largest structural castings, we can provide you with the technical assistance and quality products to utilize low-maintenance, cost-effective, valve-less vacuum or chill venting to reduce air and gas porosity. As the premier North American manufacturer of valve-less vacuum blocks and chill vents we provide both a standardized line for efficient design and process planning and customized products for specific tooling.

P/NWLTEvacuation Area (.in2)PDFSTPIGS
SV-Mini2.2503.5401.000.035Download DownloadDownload
SV-25002.5005.9402.000.040Download Download Download
SV-40003.9385.9402.000.070Download Download Download
SV-45004.5665.9402.000.080Download Download Download
SV-55005.5125.9402.000.100Download Download Download
SV-55405.5125.9402.000.100Download Download
SV-65006.5005.9402.000.120Download Download Download
SV-80008.0006.4402.000.140Download Download Download

Click on an image below to download a .pdf of the catalog page.

Stationary side


Ejector side


Standard Valve-Less Vacuum Blocks are manufactured from premium H-13, heat treated to 44-46 HRC and stress tempered for long life. Standard Valve-Less Vacuum Block part numbers begin with SV- (SV-XXXX).

E-Series Valve-Less Vacuum Blocks are manufactured from pre-hard H-13 and finished with a Melonite surface treatment. E-Series blocks are intended for use when casting zinc or magnesium, or for short-run aluminum die casting. E-Series Valve-less Vacuum Block part numbers end with -E (SV-XXXX-E).

Copper for greater thermal conductivity

For applications that require the greater thermal conductivity in their casting application Midland offers two options.

Super Chill Blocks


Receive the thermal advantage of copper flow areas combined with the long life of an H-13 holder block. Inserts are replaceable to reduce costs over life of block.

Complete Copper Blocks


Can be manufactured to your custom or Midland standard designs.

Let the experts build your custom vacuum blocks!

Let the Valve-Less Vacuum and Vent Block experts design and manufacture your custom chill vents. Our machinery and manufacturing is specifically set up to for efficient manufacturing of chill vents. Every tooth is inspected on our CMM to ensure that your die has the evacuation areas that you have planned for. Email your print or CAD model to or, if you require design assistance, please callus at (763) 428-4229.


  • Reduce porosity related scrap
  • Improve part cosmetics
  • Reduce press time to fill quotas
  • Improve part fill


Incorporating vacuum-assist when first quoting a part can help to maximize job profitability and minimize potential loss by ensuring proper air and gas evacuation from the start.


  • Higher casting yields
  • Faster job completion with less press time
  • More efficiency in casting process


  • High fallout rates due to porosity or poor fill
  • Downtime while troubleshooting
  • Resources spent troubleshooting


Vacuum-assist can be a highly effective remediation tool when a casting presents unacceptable or undesirable fallout rates due to poor fill or excessive air and gas porosity. Midland Technologies provides the service of reviewing specific casting porosity and fill issues to evaluate applicability of vacuum-assist.

  • Valve-Less Vacuum Blocks are installed into a pocket cut directly into the die set or mounted to the outside of the die using support blocks.
  • Locating pucks are utilized to ensure critical alignment between the stationary and moveable sides of the Valve-Less Vacuum Block.
  • Vacuum hose is connected to the Valve-Less Block nipple via a clamp or threaded barb. Please note that threaded barbs must be requested at time of block purchase or can be purchased separately at a later time.


  • A runner system is cut from the cavity insert to the Valve-Less Vacuum Block providing a highly efficient means for evacuation of air and gas from the cavity. Midland can design your exit runner scheme when you purchase purchase Midland Valve-Less Vacuum Blocks and provide a 2D layout of your die.


When utilizing Valve-Less Vacuum Blocks the vacuum system may be kept in the “on” or “open” condition throughout solidification. Note that Valve-Less Vacuum Blocks can also be utilized for passive venting by simply disconnecting them from the vacuum system.

Click on image below to download larger image


Correct installation is critical to proper function

Ensure parting line of blocks is flush with, or .001 – .002 proud to cavity inserts

Blocks inserted at least 4.50″ from the edge of the mold base

Inlet of blocks should be flush to the die cavity insert and mate evenly in closed condition

Correctly machine pockets to ensure no shift in locating key

Use vertical mounting holes when running with water

Manage velocity with properly designed exit runners

Excessive velocity in metal exiting the cavity can lead to several failure points when using vacuum-assist. To achieve the best possible results with Valve-Less Vacuum Blocks we recommend managing velocity of metal as it exits the cavity to help prevent solder, flash, spitting or runner washout.


Midland Technologies can supply you with a recommended exit runner design when Midland Valve-Less Blocks are purchased!


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