Wafer Vortex Flow Meter

A wafer flow meter (wafer-type, sandwich body) has no flanges of its own; the meter is a short spool that sandwiches between the two existing pipe flanges, held by long through-bolts. At the same DN it is roughly 60% shorter face-to-face, 40% lighter, and 20-30% cheaper than the flanged LUGB. Accuracy and turndown match the flanged equivalent; the trade-off is pressure range (PN16–PN40 wafer vs PN64–PN100 flanged). Below PN40 / 250 °C; HVAC, district energy, low-pressure steam, pharma loops; the wafer is the right answer.

No; accuracy and turndown are identical to the flanged LUGB at the same DN: ±1.0% standard, ±0.5% on the VRd version, 1:15 and 1:70 turndown respectively. The bluff body, piezoelectric sensor, and on-board electronics are the same hardware; only the body’s face-to-face length and bolt arrangement change. The 1:70 VRd turndown in particular is why some buyers pick wafer over flanged for sub-measurement service; they still get the leakage-catching low-flow resolution in the shorter, cheaper body.

The body is machined to sit concentric between any of: ANSI B16.5 Class 150# and 300# raised-face, DIN EN 1092 PN16 / PN25 / PN40, or JIS B2220 10K / 20K. Specify the flange standard and rating at quote time and we supply a matching gasket and through-bolt set sized to your standard. The meter is the same casting across standards; only the bolt-through circle diameter and gasket kit change. This makes wafer especially useful for international retrofits where you may not know the upstream flange standard until the line is opened.

Much faster in most cases. A flanged meter swap requires removing the existing meter, cleaning both pipe flanges, and installing a unit whose bolt-pattern circle must match exactly. The wafer slides into the existing gap between pipe flanges; you only need the gap to be ≥ the wafer face-to-face (typically 65 mm for DN25, 150 mm for DN250). Most orifice-plate retrofits and many old rotameter replacements can be done in-gap without pipe re-work. Budget 1-2 hours for a wafer retrofit versus 3-5 hours for a flanged swap.

Both. The wafer body handles liquid (HVAC chilled water, hot water, condensate, CIP/SIP solutions, WFI), gas (compressed air, nitrogen, low-pressure natural gas), and steam (saturated and superheated up to 250 °C / 4.0 MPa). Above 250 °C / PN40 you need the flanged form for gasket retention and bolt-load margin; the wafer body is pressure-limited by the bolts clamping through the full length, not by the casting itself, so the operating range is set by the sandwich geometry. For mid-pressure saturated steam, hot oil to 250 °C, and low-pressure superheated at utility service, wafer is the standard specification.

For clean-utility service such as CIP cleaning loops, SIP steam-in-place, and pharma compressed-air headers the wafer LUGB ships with 316L wetted parts as standard. For 3A-dairy or sanitary-fitting service (tri-clamp connections, fully drainable) the wafer bolt-through flange arrangement is not compatible; for that service specify a sanitary tri-clamp meter with quick-release clamp fittings instead.

The difference between wafer and flange connection comes down to three things: face-to-face length, pressure range, and install time. The wafer-type meter sandwiches between two pipe flanges and is clamped by long through-bolts; roughly 60% shorter face-to-face, 40% lighter, and 20-30% cheaper than an equivalent flanged body at the same DN. The trade-off is pressure range: wafer is rated PN16–PN40, the flanged LUGB extends to PN64 / PN100. Below PN40 and 250 °C the wafer is almost always the right answer; above either threshold, specify flanged.