B18Hx20/1P-SC-U 4xS28.58&W35.1

B18Hx20/1P-SC-U 4xS28.58&W35.1 designates a SWEP B18 brazed plate heat exchanger with 20 plates in the pack. The H plate is the obtuse chevron: it gives the most heat transfer per plate and the most pressure drop, so it suits duties where approach temperature matters more than pump head. Reading the string: /1P is single pass; -SC is 316/316L stainless steel plates joined with copper. The closing U is the pressure class: 64 to 140 bar. The connection field reads 4xS28.58&W35.1. 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 consistant in every other field and still not pipe up.