B18Lx20/1P-SC-U 4xS28.58&W35.1

The B18Lx20/1P-SC-U 4xS28.58&W35.1 is a 20-plate build of the SWEP B18. 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 U is the pressure class: 64 to 140 bar. Connections are listed as 4xS28.58&W35.1, in port order. The B18 plate pack measures 377 x 119.5 mm (14.84 x 4.7 in) on 329 x 72 mm port centres, and by SWEP's published weight formula a 20-plate unit comes to about 9.0 kg (19.9 lb) dry. The frame is published to 9 m3/h (39.63 GPM) - a port limit rather than a design flow. Check the connection field separately from the plate count: two units can be consistent in every other field and still not pipe up.