SWEP B18

On CO2 duty an undersized unit costs more than capacity. A gas cooler with too little surface leaves the CO2 warmer than intended, and the system makes up for it at the compressor. Nothing fails; the plant just runs inefficiently for years.

Oversizing is less damaging thermally but expensive in every other way. Each plate adds 0.2504 kg, so a 100-plate pack is about 29 kg (64 lb) against roughly 14 kg (31 lb) at 40 plates, with the refrigerant hold-up rising in step. Catalogued counts on file run from 10 to 140, so there is no need to round far in either direction.

Field by field. B18 is the frame. H is the plate type, the obtuse chevron with high heat transfer and high pressure drop. x80 is the plate count. /1P is single pass. SC is 316/316L stainless plates with copper braze. U is the pressure class.

The last group is the connections: four identical ports, and the ampersand marks a combo connection that accepts two joining methods or sizes, here given as S28.58 and W35.1. Quote that group exactly as stamped. Every catalogued B18 string on file carries the same connection set, with H or L plates and counts from 10 to 140. The Model Number Guide covers each field in detail.

It is the port ceiling, 9 m3/h, and it is a liquid-flow figure. On a gas cooler or a CO2 water heater it applies in practice to the water or glycol side. The CO2 side is sized on mass flow and allowable pressure drop, and those come out of the rating, not off the datasheet header.

A unit comfortably inside 39.63 GPM on water can still be wrong on the CO2 side. If the water flow itself is pressing the ceiling, the duty has outgrown the frame and the next CO2 size up is the place to look.

No. U is a category spanning 64 to 140 bar. An individual unit carries one stamped design pressure somewhere in that span, set by its build, and that stamped figure is what the replacement has to equal or exceed.

Read the design pressure and temperature for both sides off the old nameplate and send them with the string. Never fill the gap with a lower-class unit of similar size. Frames with nearly the same face dimensions exist in ordinary refrigerant classes, and they are not a substitute at any plate count.

The catalogued builds are SC: 316/316L plates with copper braze. CO2 is the reason the frame exists, and on the secondary side water, glycol mixes and heat transfer oils are all fine with that construction.

The limit to watch is on cascade systems. Where CO2 is condensed against ammonia, the ammonia side rules out copper braze, so an SC unit is the wrong build however well the pressure class fits. Deionized water on the secondary side is excluded for the same copper reason.

The full designation off the nameplate, including the connection group, and the article number if it is shown. With those the unit is identified completely.

If the plate is damaged, send what survives plus four things: the plate count, the stamped design pressure and temperature for each side, clear photographs of the connections, and the duty - both fluids, flows, and temperatures in and out. On a U-class unit the pressure rating is the item we will not estimate, so if it is unreadable, give us the system design pressures and the relief valve settings. Send it all through Request a Quote and availability is confirmed with the quote.