SWEP B26

Upright, always, on two-phase duty. An evaporator or condenser laid on its side separates liquid from vapor across the plate width, and it loses capacity in a way no adjustment will recover.

The connection string tells you which ports are which. A catalogued set such as 9.65+16+2x1"&22U has two small connections of different sizes and two large matching ones. The small pair is normally the refrigerant circuit and the large pair the water circuit. Pipe the water counter-current to the refrigerant, and support the lines so the small refrigerant stubs carry no weight and no compressor vibration.

As a limit on the water side, and nothing more. 49.75 GPM (11.3 m3/h) is what the ports will pass.

On this frame the water normally runs through the larger 0.066 dm3 channels, which is why a B26 reaches a given water flow at a lower pressure drop than a symmetric plate of the same face. If your selection still shows the water pressure drop out of bounds at the full 160 plates, the ports are the constraint and the duty belongs on a frame with larger connections. Pressure Drop covers the checks.

Start with whatever letters follow "B26". The catalogued strings on file include both B26H and B26FH, and those are different plate arrangements. One letter decides which you have.

Then the measurable facts: 376 x 119 mm face, 329 x 72 mm port centres, and the plate count off the edge of the pack. Record each connection size in port order, since the refrigerant pair is usually two different sizes. Last, write down the refrigerant and what the unit did - evaporator, condenser or both in a reversible machine. A V26 has the same face and the same published flow, and the duty is often what separates the two when the label is gone.

Both are catalogued. Strings on file carry NC (304 plates) and SC (316/316L plates), each with copper braze, and all in the M pressure class - the category fatigue tested for refrigerants such as R410A. Where the water is open, untreated or unknown, SC is the one to specify.

Ammonia is excluded because of the copper braze, and so is deionized water. Chloride-bearing water pits even the 316 version. One more water-side limit applies: the 0.7 mm particle size means an open cooling-tower loop needs fine straining ahead of the unit, whatever the plate grade. Refrigerant Compatibility lists the refrigerant side.

Single pass is the norm. The datasheet example is B26H/1P-SC-F and the catalogued strings on file read /1P.

That fits the duty. Evaporators and condensers need the refrigerant to travel the plate once, bottom to top or top to bottom, with all the refrigerant channels fed in parallel from one port. Extra passes would add pressure drop on a stream where pressure drop costs saturation temperature. So when a B26 comes up short, the correction is more plates, up to the 160 maximum, and not another pass.

Read the connection group one port at a time. In 9.65(20)+22U(20)+2x1"(20) the ports are, in order, a 9.65 mm connection, a 22U universal solder connection and two 1 in connections, each with a bracketed suffix that belongs to the specification. A 22U takes both 7/8 in and 22 mm tube. An ampersand, as in 1"&22U, marks a combo connection that accepts either method.

The liquid-side sizes vary between catalogued builds - 6.5, 9.65 and 12.8 all appear on file - so do not assume the small connection on your unit is the common one. Measure the tube it was brazed to. A mismatch there means a reducer on a refrigerant line, and that is one more joint to leak.

The refrigerant inlet. The two share the 376 x 119 mm face, the 49.75 GPM ceiling, 316/316L plates and copper braze. The V26 starts from the B26 condenser design and adds a V-ring distribution system at the refrigerant inlet, aimed at reversible air-to-water heat pumps where the same exchanger has to evaporate as well as condense.

A B26 fitted in place of a V26 will bolt up and then underperform in evaporating mode.

These models are catalogued alongside the B26. Each has its own page with its dimensions, materials and part numbers.

SWEP V26 - B26-based AsyMatrix unit with V-ring refrigerant distribution for reversible air-to-water heat pumps.