B12Lx20/1P-SC-S 4x1 1/4" INT HEX(27)

This is the 20-plate B12: SWEP designation B12Lx20/1P-SC-S 4x1 1/4" INT HEX(27). The L plate is the acute chevron, which gives up some heat transfer per plate for a lower pressure drop - the usual answer when the available head is small. The /1P-SC fields read as single pass, with 316/316L stainless steel plates and a copper braze. The closing S is the pressure class: 31 bar at 155 C. The connection field reads 4x1 1/4" INT HEX(27). The B12 plate pack measures 287 x 117 mm (11.3 x 4.61 in) on 234 x 63 mm port centres, and by SWEP's published weight formula a 20-plate unit comes to about 2.3 kg (5.1 lb) dry. Maximum flow for the frame is 16.9 m3/h (74.41 GPM); that is a ceiling for the ports, not a duty point. Depth is the one dimension that changes across the plate counts of a series, so measure the space behind the unit before moving to a larger pack.