SWEP E5T

The designation on the exchanger itself, for example E5THx12/1P-SC-S, with its connection code, or the SWEP article number. On the E5T the connection code is the part people leave off, and it is the part that matters most: catalogued configurations include 3/4" threaded ports and versions listed with plain port holes.

If the label is gone, send the outline, the port centres, the plate count and a clear photo of the port face showing whether there are threaded stubs or flat holes with seal seats. The boiler make and model help as a cross-check, but the exchanger's own numbers are what identify it.

All five publish the same 17.61 GPM ceiling, so flow does not separate them. Size and plate design do. The B5T and B5AS are 193 x 76 mm; the E5T and E5AS are 192 x 73 mm; the B5 is smaller again at 187.5 x 72.5 mm and is shown nickel brazed, where the others are copper brazed.

The E5T uses its cover plates for heat transfer. The E5AS has the same outline with AsyMatrix asymmetric channels, optimized for hot tap water. The B5AS is described for small oil or water coolers. An E5AS will physically fit where an E5T was, but it is a different plate and will not perform identically.

Because it controls how quickly hot water arrives and how the unit behaves between draws. SWEP publishes the same per-channel volume on both sides of the E5T, and with at most 41 plates the total on each side is very small.

A small hold-up means the tap-water outlet reaches temperature within moments of the burner firing, which is the point of a plate exchanger in an instantaneous boiler. The other side of that is scale: the little water left standing in hot channels after a draw is where hardness deposits first. In hard-water areas the first sign is a falling hot-water flow rate or temperature swings at the tap.

PED, UL and KHK - the European pressure equipment route, the North American listing and the Japanese high-pressure gas approval.

For a component inside an appliance, the appliance's own certification is the one the installer answers to, and it was granted with a specific exchanger fitted. That is the practical reason to replace an E5T with the same designation rather than something close: a different plate count or connection may still work hydraulically but is no longer the part the boiler was approved with. The approval marks on the unit you recieve are the ones that apply; if a particular mark is needed, say so when asking for a quote.

It is the pressure class. Every E5T part number on file is S class, the general-duty category of 31 bar at 155 C. That is a class envelope, not the stamped rating of an individual unit; the nameplate figures govern.

On boiler duty the system runs far below that, so the class is rarely the limiting factor. It still needs to be read correctly, because the letter sits right after the material code - in E5TH/2P-SC-S, SC is the material and the final S is the class. The Pressure Classes page lists the others.

It is right where it was designed to go: inside a wall-hung, non-condensing boiler, transferring heat from the boiler circuit to another water circuit in the smallest possible space.

It is the wrong choice as a general-purpose small exchanger on a plant-room wall. The 41-plate limit caps its capacity, and configurations with plain port holes need a manifold to seal against rather than a pipe to screw onto. Its 316/316L plates and copper braze also rule it out for ammonia, deionized water and chloride-heavy water. For a free-standing small duty, a B-series unit with standard connections is easier to pipe and to support.

Up to 41 on the datasheet, with part numbers on file from 10 to 40 plates - 10, 12, 14 and 20 among them. More plates mean more channels, lower pressure drop and more heat transferred at the same flow.

In a boiler the count is tied to the appliance's output, so a replacement should carry the same count as the original. Weight is trivial at any count: the published formula is 0.29 kg plus 0.04 kg per plate, which puts a 40-plate unit at about 1.9 kg (4.2 lb).

These models are catalogued alongside the E5T. Each has its own page with its dimensions, materials and part numbers.

SWEP B5T - Compact 316 stainless frame for low-flow heating and cooling loops.

SWEP B5 - Very compact brazed plate heat exchanger for small flows, used as a small oil or water cooler.

SWEP B5AS - Very compact AsyMatrix brazed plate heat exchanger for low flows - small oil and water coolers.

SWEP E5AS - AsyMatrix brazed plate heat exchanger on the B5T frame, built for hot tap water production in boilers.