SWEP DV700

It is designed for chillers and heat pumps with two refrigerant circuits, where one exchanger serves both circuits and either can run alone. The AsyMatrix plate gives the refrigerant side and the water side different channel geometry - the point of a plate that is built for a refrigerant on one side and water on the other.

It does not belong on duties with two similar liquids, where an asymmetric plate has no advantage. It does not belong on ammonia, which attacks the copper braze, or on deionized water. And its 304 plates are meant for ordinary treated water: on chlorinated or brackish water the plates are at risk of pitting. Plate and Brazing Materials covers the alternatives.

The published empty weight is 11.73 kg plus 0.609 kg per plate. A 50-plate unit comes to about 42 kg (93 lb), a 220-plate unit about 146 kg (321 lb), and the 362-plate maximum about 232 kg (512 lb).

Mount it vertically on a support that carries the plate pack itself. Anything beyond the smallest plate counts is a mechanical lift, and the connections must never be used as handles or lifting points. Add the weight of the water and refrigerant charge when sizing the bracket or base.

An undersized unit shows a wide gap between leaving water and refrigerant temperature, high water pressure drop, and a compressor working against a worse pressure ratio than it was selected for. Capacity comes up short on the design day.

An oversized unit is harder to spot. Refrigerant velocity in the channels is low, oil return is poor, and control becomes unsteady at part load - particularly when one of the two circuits is off. The usual cause on a replacement is rounding the plate count up "to be safe". Keep the original plate count unless the duty has changed, and if it has, have the unit rated at minimum load as well as full load. See Plate Count and Capacity.

Work from the machine outward. The chiller or heat pump nameplate, its parts list or its service manual will normally give the exchanger designation, and that is more dependable than measuring.

If measuring is all that is left, the outline of 725 x 302 mm and port centres of 546 x 191 mm place it in the 700-series True Dual group, and a plate-edge count gives the plate number. That still leaves three models. Since the outline is shared, the model letter has to come from a document, not from the tape. Send us the measurements, photos of all connections and the machine's model and serial number, and we will confirm the unit.

These models are catalogued alongside the DV700. Each has its own page with its dimensions, materials and part numbers.

SWEP B427 - 420 plates, dual circuit, 685 GPM.

SWEP DB650 - True Dual brazed plate condenser, 744.6 x 365.6 mm, up to 346 plates, 140 m3/h maximum flow.

SWEP DB700 - True Dual brazed plate heat exchanger, 725 x 302 mm, 304 stainless plates, up to 362 plates.

SWEP DP700 - True Dual brazed plate evaporator, 725 x 302 mm, 316/316L plates, up to 362 plates.