Cross-Reference by Brand

Rarely without some change. Port centre distances are particular to each maker's plate, so even a unit of the same height and width seldom lands on the same four pipe positions. Pack depth also differs, because the plate count needed for the duty is not the same from one plate design to another.

Plan for some repiping at the connections. Tell us which pipes can move and which cannot, and the connection type you want to keep - threaded, solder or flange - and we will choose the frame that asks for the least rework.

Because a plate count only means something within one plate design. Plate area, chevron angle and channel depth all vary between makes, so the same number of plates can give noticeably more or less heat transfer and a different pressure drop.

It varies within SWEP as well: an H plate transfers more heat at a higher pressure drop than an L plate on the same frame. Use the old plate count as a clue to the size of the duty, then let the selection set the new one.

As a grouping by port size, nothing finer. Maximum flow is a ceiling set by the ports, so frames in the same row, such as the B10T, B25T, B86 and B26 at roughly 39 to 50 GPM, can pass similar water flows while differing in plate length, channel volume and pressure class.

The table tells you where to start looking. It does not say that two units in a row perform alike, and it says nothing useful about a refrigerant duty.

We need the refrigerant duty, not just the dimensions. Give the refrigerant, the capacity, the evaporating or condensing temperature, the superheat or subcooling, and the water-side flow and temperatures. Note which port the refrigerant enters, and wether the unit has one refrigerant circuit or two.

Evaporators in particular depend on a distribution device at the inlet ports that is matched to the duty, which is why SWEP builds dedicated evaporator models on its frames. A plain water-to-water frame of the same size is not a substitute.

Measurements and a photograph. Take the height and width of the plate, the depth of the pack, the distances between port centres in both directions, and the size and type of each connection. Count the plates along the edge of the pack; the edges are visible even when the label is gone.

Add the make and model of the machine it came out of and what each of the four ports connects to. That is normally enough to identify the frame class, and the Model Number Guide shows what the finished designation will look like.

Yes - they are part of the cross-reference, and the part most easily forgotten. Read the design pressure, design temperature and any code marks off the old label. The replacement must meet them through its pressure class and approvals, whatever its size.

Two details deserve attention. A double-wall unit has to be replaced with a double-wall unit, because the wall type is usually there to satisfy a potable-water rule. And a potable approval carries its own temperature limit: NSF/ANSI 61 is limited to 90 C. See Approvals and Certifications.