When you move up to a 4-inch (100mm/DN100) "Original" Water Meter, you are dealing with a heavy-duty Bulk Flow Meter (typically a Woltman type). These are the "master meters" used by municipal water authorities, large-scale commercial farms, and industrial plants to monitor main trunk lines.
1. Key Technical Specifications
Size: 4-inch (DN100).
.Connection: Flanged (Standard PN16 or PN10). These are too large for threaded unions and require bolted flange gaskets.
Body Material: Heavy Cast Iron or Ductile Iron with a thick, anti-corrosive epoxy coating (usually blue).