SWEP DB650

Height and width first: 744.6 x 365.6 mm (29.31 x 14.39 in). That outline is distinctive among the True Dual models, so if the unit in front of you measures close to 725 x 302 mm it is a 700-series model and not a DB650.

Next is the depth of the plate pack, which follows plate count. The model is built up to 346 plates and the part numbers on file run from 50 to 220, so depth varies widely between units carrying the same model name. Then record each connection: its type, its size and where it sits on the cover plate. A sketch or a photo with a tape in the frame is enough.

Empty weight is published as 14.59 kg plus 0.939 kg per plate. That works out to about 61.5 kg (136 lb) at 50 plates, 221 kg (488 lb) at 220 plates and 339 kg (748 lb) at the 346-plate maximum, before the fluid inside is counted.

A unit of this weight belongs on a base or a frame that supports the plate pack directly. Plan the lift before the old unit comes out, and never use the connections or the attached pipe as a lifting or bearing point. Once it is set, support the pipework independently so nothing hangs on the ports.

DB650x170 is the short form: DB650 is the model - D for True Dual, B for the plate series, 650 for the size - and x170 is the plate count.

The nameplate continues past that point. After the plate count comes a slash and the pass arrangement, then the material code, then the pressure class letter, then the connections in port order. The published construction for this model, 316/316L plates with copper braze, corresponds to the SC material code. The class letter matters here because the model is published for pressures up to 49 bar (710 psi), and the letter records which category the original unit was built to. The Model Number Guide covers each field.

It is larger in plan and higher in flow. The DB650 measures 744.6 x 365.6 mm with a ceiling of about 616 GPM; the three 700-series models measure 725 x 302 mm and are published at about 555 GPM.

The duty differs too. The DB650 is published as a condenser for chiller, heat pump and single-phase applications, while the published descriptions of the DB700, DP700 and DV700 are evaporator and refrigerant-circuit duties. Materials are another split: the DB650 and DP700 use 316/316L plates, the DB700 and DV700 use 304. None of the four substitutes for another without re-rating and re-piping.

It is the port limit, not a design point. At 140 m3/h (about 616 GPM) the ports are at the published ceiling regardless of how many plates are behind them, and pressure drop near that flow is high. Most duties are selected comfortably under it.

If the condenser water flow is above the ceiling, more plates will not help. The options are a frame with larger ports - the single-circuit B427 is published at about 685 GPM - or splitting the flow across two units in parallel. On a two-circuit machine, two units also means re-thinking how the refrigerant circuits are divided, so treat it as a new selection.

Yes, in place, by circulating a cleaning solution through the water side. A brazed unit has no gaskets and no frame to open, so cleaning in place is the only method - which is also why a strainer ahead of the water inlet matters more here than on a gasketed exchanger.

On a condenser fed by open cooling water, scale and biological fouling show up as rising head pressure and a growing water-side pressure drop. Clean when the trend appears rather than when the machine trips. Choose a cleaning chemical compatible with both stainless steel and copper, flush thoroughly afterward, and see Cleaning in Place for the procedure.

These models are catalogued alongside the DB650. Each has its own page with its dimensions, materials and part numbers.

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

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.

SWEP DV700 - True Dual AsyMatrix brazed plate heat exchanger, 725 x 302 mm, 304 plates, up to 362 plates.