B28Hx66/1P-SC-S 4x1 1/4"(D24.70)

B28Hx66/1P-SC-S 4x1 1/4"(D24.70) designates a SWEP B28 brazed plate heat exchanger with 66 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. 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. It is catalogued with 4x1 1/4"(D24.70) connections. The B28 plate pack measures 526 x 119 mm (20.71 x 4.69 in) on 470 x 63 mm port centres, and by SWEP's published weight formula a 66-plate unit comes to about 12.9 kg (28.4 lb) dry. The frame is published to 16.9 m3/h (74.41 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.