SWEP DB310

Vertically, as with any unit in two-phase duty, so that vapor and liquid separate the way the plate was designed for. Pipe the water counter-current to the refrigerant; that arrangement gives the closest approach, and on a dual unit it applies to both circuits.

Support the unit under the plate pack and support the piping separately so the connections carry no load. A two-compressor machine gives the unit two sources of pulsation. Vibration eliminators and proper line supports protect the braze joints at the connections, which is where fatigue cracks start. See Mounting and Piping.

That depends on the material code stamped on the unit, so read it before deciding. SC means 316/316L plates with copper braze, the general-duty construction for refrigerants with water or glycol.

Whatever the plate, a copper-brazed unit is wrong for ammonia and for deionized water. Chloride-bearing water - chlorinated tower water, brackish or seawater-cooled loops - pits ordinary stainless, and a pinhole on a dual unit means water in a refrigerant circuit. If the water side is anything other than a treated closed loop, tell us what it is. Background is under Plate and Brazing Materials.

The model is built with up to 350 plates. The 18 configurations on file run from 50 to 220 plates and include 50, 90, 130 and 170.

More plates give more surface and more parallel channels, so the refrigerant temperature moves closer to the leaving water temperature and the water pressure drop falls for a given flow. The unit also gets deeper, heavier and holds more refrigerant. The published 264.17 GPM does not rise with plate count, because the ports set it.

DB310 is the model: the True Dual unit of the 310 size. x170 is the number of plates. Nothing in those two fields describes materials, rating or connections.

Those come next on a full nameplate - pass arrangement after a slash, then a material code, then a pressure class letter, then the connections listed in port order. On a dual unit the connection list is long because it covers two refrigerant circuits and the water side. Units stamped under the current name read DBD310; it is the same model.

It can usually be cleaned if the fouling is caught early. Brazed units are cleaned in place by circulating a suitable solution through the water side, against the normal flow direction, followed by a thorough flush.

What cannot be fixed is a leak between circuits or channels that are fully blocked, because cleaner only goes where there is flow. A rising water pressure drop at the same flow, or a refrigerant pressure drifting away from normal at the same water conditions, is the early sign. If one circuit is already tripping on its pressure safety, a new unit is normally the quicker repair.

Record every character you can read, in order, with gaps marked. The model and the plate count are the most useful fields, and the last letter before the connection list gives the pressure class.

Then measure the unit: height, width, depth of the plate pack between the cover plates, and the spacing between connection centers. List each connection with its type and size and note which are refrigerant and which are water. Add photos of the front cover and the machine's own data plate. With those we will confirm the configuration.

These models are catalogued alongside the DB310. Each has its own page with its dimensions, materials and part numbers.

SWEP B30 - A cross-flow frame in the 200 to 400 GPM band.