SWEP DP700

The model prefix and the plate count. DP700 followed by x and a number fixes the model and the depth, and those two alone are enough to start a selection.

After that, the most valuable fragments are the pressure class letter at the end of the dash-separated codes and the connection string, since neither can be reliably judged by looking at the unit. If only the prefix is doubtful, remember that the DB700 and DV700 are the same size, so dimensions will not resolve it; the chiller's model and serial number will. Photograph the plate at an angle with a light held low - stamped characters often show in relief when they cannot be read straight on.

Outline 725 x 302 mm (28.54 x 11.89 in), port centres 546 x 191 mm (21.50 x 7.52 in), and the depth of the plate pack. The first two are fixed for the model. Depth depends on plate count, and with a maximum of 362 plates the range is wide.

Then list the connections. The model is published with threaded, Victaulic and solder types, and each port is specified individually.

For the plate steel and the plate. All three are True Dual models at 725 x 302 mm with a published maximum of about 555 GPM, so size and flow do not separate them.

The DP700 uses 316/316L plates where the other two use 304, which gives more corrosion margin on the water side. It is also the model described as an evaporator optimized for high performance in flexible chillers and climate control, while the DV700 is the AsyMatrix model with asymmetric channels. On a replacement there is no choice to make - stay with what the nameplate says. On a new selection, water quality is usually what decides it.

For a replacement, the full nameplate designation is enough: model, plate count, pass arrangement, material code, pressure class and connection string. A clear photo of the nameplate covers all of it.

For a new selection, the duty is needed instead: the refrigerant, the capacity of each circuit, evaporating temperature and superheat, entering and leaving water temperatures, water flow, the allowable water-side pressure drop, and whether the fluid is water or a glycol mix and at what concentration. State whether both circuits always run together or one runs alone at part load, because that changes the rating. With those in hand, Request a Quote and we will come back with a designation.

Too few, and the unit runs with a wide approach: the evaporating temperature drops to make up for the missing surface, compressor efficiency falls, water pressure drop is high, and the margin against freezing shrinks.

Too many is less obvious and just as real. The refrigerant is spread over more channels than it can fill properly, velocity falls, oil return suffers and the superheat signal becomes unstable, so the expansion valve hunts. On a True Dual unit this is sharpest at part load, when one circuit is off and the other sees the whole pack. An evaporator should be rated for its lowest operating load as well as its highest.

Vertical, with refrigerant entering at the bottom and leaving at the top as on any plate evaporator, and with the water counter-current to it. Counter-current flow gives the closest approach; a co-current hookup costs capacity that the machine cannot get back.

Support the unit under the plate pack and support every pipe separately. Keep vibration from the compressors out of the connections with proper pipe supports and, where the machine design allows, vibration eliminators - pulsation and water hammer fatigue the braze joints over time. Mounting and Piping has the layout guidance.

These models are catalogued alongside the DP700. 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 DV700 - True Dual AsyMatrix brazed plate heat exchanger, 725 x 302 mm, 304 plates, up to 362 plates.